Revised 12/10/24
Dictionary Index: Jump to initial letters of words: |
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Abamectin A mixture of avermectins which are metabolic products of Streptomycaes avermitilis. It is an effective anthelminthic and insecticide. See avermectin. ivermectin.
Abaxial Not situated in the line of the axis. Directed away from the axis.
abd Anal body
diameter, body diameter at level of anus, used as a measure of distances
between structures, or size of structures, in posterior region, usually of
females.
Abduce
To draw or lead away.
Abduct
To draw away from a position near or parallel to the median axis.
See
adduct.
Abduction
A drawing away.
A
retraction. See adduction.
Abductor Muscle
Any muscle that draws away from the main axis or extends or draws parts from the
body. See adductor muscle.
Aberrant
Deviating from the usual type or form. Abnormal.
Abiogenesis
The theoretic arising of living from nonliving matter. Spontaneous generation.
See biogenesis.
Abiotic
Pertaining to or characterized by non- living, inanimate phenomenon or objects.
Abnormal
Deviating from the usual type or form. Aberrant.
Abomasum. The
fouth stomach of a ruminant which receives food from the omasum and passes
it on to the small intestne, See omasum.
Aboral
Remote from or opposite to the mouth.
Aborigines
The indigenous fauna and flora of a geographical region.
Abort
To arrest embryonic development.
Aborted Unsuccessful development rendering a
part or organ unfit for normal function.
Abortion
The unsuccessful or imperfect development of any entity or normally present part
or organ.
Abortive
Unsuccessful embryonic development. Rudimentary.
Abraded
Scraped, rubbed or worn away.
Abrupt
A sudden transition. Without gradation.
Abscissa
(pl.
Abscissas, Abscissae)
The transverse line perpendicular to the vertical line (ordinate) to show by
graphic design the relations of two series of facts.
Absent Buccal Capsule
When an embedded buccal capsule has walls of the same consistency as the lining
of the esophagus the buccal capsule is said to be absent.
Absorb
To take something within the body. See adsorb.
Abullate
Lacking bullae. See bullae.
Abundance A measure of the frequency of entities such as species in a community or guild measured in terms of numbers of individuals, biomass of individuals, contribution to ecosystem function or metabolic footprint of the entities.
Abyssal Environments at ocean depths or on the bed of the
ocean.
Abyssal Fauna
Organisms dwelling at oceanic depths below 6,000 feet,
quiet water,
complete
darkness. See benthnic fauna, pelagic fauna.
Acanthiform-shaped
like a thorn. See corniform.
Acaudal
Lacking a tail.
Acaudate
Lacking a tail.
Accentuation
Increased distinctness.
Accessory
Certain subordinates that are auxiliary in function, course, etc., to the
principal.
Accessory Piece
The gubernaculum.
Accessory Sexual Structures
The spicules and gubernaculum of the male nematode.
Accidental Host. An organism that accidentally harbors a paraite that is not normally a parasite of that species.
Acclimate
To cause or the process of becoming accustomed to a new environment. To
acclimatize.
Acclimatize
To acclimate.
Acclivous
A gentle rise. An upward slope.
Accrescent
A gradual increase in thickness toward the apex.
Accretion
The manner by which crystalline and certain organic forms increase by growth of
external addition, Also, the joining of parts normally separate.
Acerate
Needle-shaped.
See acerose, acicular,
pointed.
Acerose
Needle-shaped. See acerate, acicular, pointed.
Acephalous
Lacking a head.
Acescence
The process of becoming sour.
Acicular
Needle-like. Having a long, slender point.
Aciculum
(pl. Aciculums, Acicula) A seta.
Acidobiotic
Living in an acid environment.
Acidophilic
A successful mode of life in an acid environment.
Acidophobic
Intolerant of an acid environment.
Aciform-shaped
like a needle. See pointed.
Aciniform
Formed like a cluster of grapes.
Acoelomate The condition of lacking a true coelom. That is, the body cavity,
if any, is not entirely surrounded by mesoderm.
Acquired Character
A character that originates during the life of an organism due to environmental
or functional cause.
Acre-foot
One foot of water over an acre; 43,560 cubic feet; or 325,851
Acre-Inch
One-twelfth of an acre-foot.
Acrocentric
Having a subterminal centromere.
Acriniform
Having a radiated form.
Active
See
alacrious.
Acuate
Pointed. See pointed.
Acute
Pointed. With a sharp terminus. See pointed.
Acuminate
Tapering to a slender point. See pointed.
Acuminose
Subacuminate.
Adcloacal
Situated in the proximity of the cloaca.
Adanal
Situated in the proximity of the anus.
Adanal
Adanal Copulatory Papillae
The adanal supplements.
Adanal Supplements
Organs of secretion and attachment adjacent to the anus of some male nematodes,
See Figure 5.
Adaptation
Modification of an organism or its parts or organs to make it more fit for
existence under the conditions of its environment.
Addendum
(pl. Addenda) An addition. A supplement. An appendix.
Adduct
To draw towards the median axis or one part toward another. See abduct.
Adduction
A drawing toward. A drawing together. See abduction.
Adductor Muscle
Any muscle that draws toward the main axis or brings parts into opposition.
See
abductor muscle.
Adeniforn
Having the shape of a gland. Gland-like.
Adhesion
The attractive force between two dissimilar bodies that are in contact.
See
cohesion.
Adhesion Tubes
Hollow tube-like setae by which some nematodes ambulate on a surface or to
adhere to a substrate in a flowing aquatic environment.
See
ambulatory setae.
Adhesive Bristles
Adhesion tubes.
Adhesive
Tube
The spinneret.
Aditus
A passage or opening as an entrance.
Adnate
Grown together especially of unlike parts.
Adsorb
To take something upon the surface of a body.
See
absorb.
Adult
A sexually mature individual. A condition achieved after the fourth molt.
Adunc
Inwardly curved. Hooked.
See
hamate.
Adventitious
Not arising from the usual place. Arising sporadically.
Adventive
An introduced species.
Aerate
To imbue with air.
Aeration
The exchange of air in soil with air from the atmosphere. The composition of the
air in a well aerated soil is similar to that in the atmosphere; in a poorly
aerated soil, the air is considerably higher in carbon dioxide and lower in
oxygen.
Aerial
Inhabiting the air. Growing or existing above ground.
Aeriform
Of the nature or form of air. Gaseous.
Aerobic
Requiring the presence of oxygen to live.
See
anaerobic, facultative aerobic, facultative anaerobic, obligatory aerobic,
obligatory anaerobic.
Aerolated
A situation where the transverse striae enter the lateral fields,
See
Figure 17.
Aestivation
Dormancy during periods of unfavorable environment.
See
dormant.
Afferent
Bearing or conducting toward an organ or position.
See
efferent.
Affinity
Relationship. Attraction. A relation among organisms where plan of organization
and structure indicate position in the overall system.
Afrotropical Realm
The biogeographical region encompassing tropical Africa and the southern
Arabian peninsula. See Holarctic Realm, Australasian Realm.
Agar
A gelatin-like substance extracted from seaweed. Agar is used in culture media
to cause it to set.
Aggregated
See
agminate.
Agminate
Aggregated. Grouped. Clustered.
Agnobiotic Culture
A nematode population with one or more kinds of organisms present.
See
pure culture, aseptic culture, monoxenic culture, axenic culture, xenic,
synxenic, monxenic, dixenic, trixenic, polyxenic.
Alacrious
Active. Lively.
Alae
(sing.
Alar
Relating to or belong to the alae.
Alate
Having alae. Possessing lateral fields.
Albumin
A class of proteins. One segregate of the cuticle.
Albuminoid Concretion
Food reserve deposits found in modified intestinal cells of some nematodes.
Aliform
Wing-shaped.
Alimentary Canal
The alimentary tract.
Alimentary Tract
The tubular food-carrying passage extending from the mouth to the anus. Its
parts are oral aperture, stoma, esophagus, intestine, prerectum, rectum, anus.
Aliquot
A part of a whole that divides the whole without a remainder,
Allele One of two or more variants of a sequence of nucleotides (or of a gene) that are located at the same genetic locus on a chromosome; a shorthened version of the term allelomorph. See allelomorph, locus.
Allelomorph Often used in the abbreviated form
"allele". See allele..
Alleyway
A path or separation between experimental plots.
Allomone
A semiochemical,
emitted by an organism, which mediates an interaction between species
that benefits individuals of a species remitting the signal and harms
individuals receiving the signal.
See
semiochemical,
kairomone, synomone, pheromone.
Alloplasm
Functionally-specialized living matter differentiated from and less active than
protoplasm, as that of cilia.
Allotype
A paratype of the opposite sex of the specimen designated as the holotype. See
type.
Alternation of Generations
See metagenesis.
Alveolate
Having pits or cells like a honeycomb.
Alveolus
(pl. Alveoli) A small cell, cavity or pit.
Amalgamated Lips
Lips fused giving a smooth or nearly smooth contour.
Ambifenestrate
In some species of the genus Heterodera
where the vulval bridge is slender and the hatching pore is typically an
hourglass shape. See fenestrate, semifenestrate, bifenestrate,
circumfenestrate, See
Figure 32.
Ambulacral Spines
Ambulatory setae.
Ambulatory Setae
Setae, sometimes hollow and tube-like, used in locomotion. See adhesion
tubes, stilt bristles, setae.
Amendment
Any material, such as lime, gypsum, sawdust, or synthetic conditioners that is
worked into the soil to make it more productive. Strictly, a fertilizer is also
an amendment but the term "amendment" is used most commonly for added materials
other than fertilizer.
Amphicoelous
Biconcave
Amphicyrtic
Biconvex
Amphid
(pl. Amphids) Paired lateral sense organs which generally open to the
exterior on or near the lip region. See
Figure 2,
Figure 4.
Amphid Aperture
The opening leading to the pouch of the amphid. See
Figure 2,
Figure 22,
Figure 22.
Amphidelphic
Having two ovaries, generally one extending anteriad and the other posteriad of
the vulva. See monodelphic, prodelphic, didelphic. See
Figure 27.
Amphidial Duct The connecting
passage between the amphidial opening and the amphidial pouch.
Amphidial Gland An organ located posterior to the
nerve ring a.id connects with the central nervous system through the lateral
ganglion.
Amphidial Nerve The nerve extending anteriad from
the nerve ring to the amphid.
Amphidial Opening The amphid aperture.
Amphidial Orifice The amphid aperture.
Amphidial Pocket The amphidial pouch
Amphidial Pore The amphid aperture.
Amphidial Pouch The cavity or chamber of the
amphid which contains the sensilla. A dilation of the amphidial gland. Sensilla
pouch
See
Figure 2.
Amphidial Tubes
The passages containing the amphidial nerves which connect the fibrillar
terminals and the sensilla. An extension of the amphidial gland.
See
Figure 2.
Amphimixis
The union of germplasm of two organisms in sexual reproduction.
Ampliation
An enlargement.
Ampulla
A membranous sac or vesicle.
Ampullate
Flask-shaped.
Ampuliform
Flask-shaped. Dilated.
Anabiosis
Act of being revived, especially after a period of desiccation.
Anabiotic
Anabiosis
Anabolism
The constructive processes iii metabolism, from digestion to assimilation.
See
metabolism, catabolism.
Anadromous Host Fish that spend part of their life in both
fresh and salt water; they return to freshwater where they spawn and become
infected by nematodes developed in the seconday host. See secondary
host, intermediate host, primary host.
Anaerobic
Living in the absence of atmospheric oxygen.
See
aerobic, facultative aerobic, facultative anaerobic, obligatory aerobic,
obligatory anaerobic.
Anal Aperture
The anal opening.
Anal Body Diameter
(Width)
The body diameter at the level of the anus; sometimes abbreviated as abd or abw. See
Anal Diameter, abd
Anal Cleft
The anal opening
Anal Diameter
The body diameter at the level of the anus.
Anal Fenestra
In the genus
Heterodera,
the opening resulting from the breakdown of the thin walled, transparent
cuticular region of the anus.
See
Figure 34.
Anal Ganglion
Receives the ventral cord and from which the anolumbar connectives extend to the
lumbar ganglia.
Anal Muscles
Muscle cells/tissue which function to make the anus operative.
Anal Opening
The orifice to the exterior at the terminus of the rectum and delimited by the
anus.
Analogue
A part or organ similar in function to a part or organ of another individual but
differing in structure and origin.
See
homologue.
Analogous
Similar in function but differing in origin and structure.
See
homologous.
Analogy
Similarity in function between parts or organs of a different origin.
See homology.
Analytical Key The resolving of the
characteristics of nematodes into their constituent parts resulting in the
selection of a particular specimen.
Anaphase A state in mitosis or meiosis in which
daughter chromosomes migrate toward the spindle poles. See prophase,
metaphase, telophase.
Anastomosis (pl. Anastomoses) The union or
intercommunication of the lumen of a system or network.
Anceps Sword-shaped.
Androdioecious Descriptive of a population expressing the characteristics of androdioecy
Androdioecy The
condition in which a population consists of both males and hermaphrodites.
See dioecy, trioecy.
Androgynous Combining the characters of both
sexes. Hermaphroditic. See hermaphrodite, reproduction.
Androtype A male type. See type.
Aneuploid Having a chromosome number that is not a
multiple of the haploid number. See monoploid, euploid, heteroploid,
hyperploid.
Aneuploidy The process or history of becoming
polyploid.
Angulate Having angles. Angled.
Anion An ion bearing a negative charge. See
ion, cation.
Anisoglottid Having the metarhabdions of the
glottid apparatus at different levels. See isoglottoid.
Anisomorphic Of dissimilar form, especially
pertaining to the metarhabdions of the glottoid apparatus. See isomorphic.
Anisotopic At dissimilar levels, especially pertaining to a glottoid part of the stoma with dorsal part anterior to the suventral parts.
Anlage: The
rudimentary basis of an organ or body part in a developing embryo. See
embryo.
Annulate Comprising or furnished with rings.
Ringed.
Annulations Deep transverse striae which occur at
regular intervals in the cuticle.
Annule The interval between the annulations. A
transverse ornamentation of the cuticle surface formed by deep striae at regular
intervals. Formed of or giving the shape of rings. See
Figure 17.
Annulet A small ring.
Annulose Ringed.
Annulus A ring-like structure or marking.
Anolumbar Connectives Connections joining the anal
or preanal ganglia with the lumbar ganglia.
Anorectal Connectives Commissures extending from
the anal ganglia to the dorsal surface of the rectum joining the dorsorectal
ganglion from which a median nerve extends posteriad to the tail.
Antagonistic Symbiosis A symbiotic association
which is disadvantageous or destructive to one of the symbionts.
Antarctic Realm The biogeographic
region that encompasses Antarctica. See Holarctic Realm
Anteapical Situated just before the apex.
Subapical.
Antemortem Before death.
See necropsy, postmortem.
Anteriad Directed forward. Opposed to posteriad.
Anterior In front. Before. The front position as
opposed to the posterior.
Anterior Cephalic Crown A crown
of six papillae or setae located immediately posterior to the labial crown of
papillae. See labial crown of papillae, posterior cephalic crown.
Anterior Cephalid The anteriad cephalid at which
the two lateral cords arise. See
cephalid. See Figure 1.
Anterodorsal Toward the front and dorsum.
Anteroposterior Axis The long axis from head tail.
Longitudinal axis.
Anteroventral Toward the front and the ventral.
Antepudendal With genital tube anterior to vulva. See
postpudental.
Anthelminthic A compound fatal to worms or causing
the expulsion of worms, especially intestinal worms.
Antibiosis An antagonism between two or more
organisms, especially microorganisms in soil, to the detriment of one of them.
Antidromic Extending or proceeding in a direction differeing from the usual. See orthodromic.
Antidromous Changing direction.
For example, antidromously reflexed ovary.
Antipathetic Symbiosis A symbiotic association
which is advantageous or necessary to one or both symbionts.
Antrorse In a forward or upward direction. See
postrorse, retrorse.
Antrum A cavity or hollow space. A sinus.
Anus The extremity of the rectum. The posterior
opening of the alimentary canal. See
Figure 18,
Figure 28,
Figure
29,
Figure 41.
Aparity Live birth
of juveniles that emerge from eggs that are still in the uterus. See
Bagging.
Aperture An opening. Hole. Orifice. The diameter
of the opening.
Apex (pl. Apices) A proximal continuation
of the aphelenchoid spicule shaft. The tip. The point of culmination.
Aphelenchoid Esophagus Having a narrow procorpus
with a strongly formed median bulb followed by a narrow tube which extends to
the intestine. A basal swelling is lacking and the three esophageal glands lie
outside the esophagus proper.
Apically Near, toward or directed toward the apex.
Apicad Toward the apex.
Apical Cell A cell of the epithelium that forms
the gonoduct wall and is situated at the distal end of the ovary and to be
differentiated from the terminal cell.
Apical Lip Notches Indented lip margins at the
confluence of the lips.
Apiculate Abruptly terminated by a fine, distinct
point.
Apneuistic Respiration through the cuticle.
Apodeme A
ridge or knob on the cuticle of the stegostome of diplogasterid nematodes
that provide muscle attachment and movement of the structure,
Apomixis, Apomictic Parthenogensis Reproduction without
fertilization and by mitotic division of egg cells. See
Parthenogenesis, Mitotic Parthenogenesis.
Apomorphy; Apomorphic Character or Trait
A character that is unique to a group or species and that may be unique
from, or represent a "recent innovation" from that found in the ancestor.
Apophysate Bearing an apophysis.
Apophysis (pl. Apophyses) A process. A
prominence. See
Figure 24.
Apotype A specimen, other than the type, upon
which a subsequent or amended description or figure is based. Hypotype.
Plesiotype. See type.
Apparition Appearance, Visible.
Appendage An external organ or limb.
Appendix An outgrowth or process, especially an
addition to what is relatively complete in itself.
Appendicle A small appendage.
Appendicule A large, single, ventral preanal
supplementary organ which is extensible.
Applied Nematology Economic nematology. The
practical use of pure nematology for control of nematode pests.
Appose To place surfaces opposite each other.
Apposition The condition of having surfaces
against each other. See Fornent, juxtaposition.
Aquatic Living in a water habitat. See
arenicolous, edaphic, hypogaeic, marine, rheophile, terrestrial, terricolous,
xerophilous.
Arakaoderan bursa Caudal alae completely surrounding the cloacal area. See leptoderan, peloderan.
Arc A bow-like curvature.
Arcade A circular band of tissue which usually
surrounds the esophagus at the base of the lips.
Arcadial Tissue A mass of cells surrounding the
stoma.
Arch A structure or form usually curved. In
perineal patterns of Meloidogyne females the curved formation of
cuticular striae above the phasmids. See
Figure 28,
Figure
29.
Arcuate Curved like a bow. Arched.
Are A measurement of area equal to 100 square
meters or 119.6 square yards.
Area Application Broadcast application of soil
nematicides.
Area Rugosa Ornamentation
of the cuticle, sometimes present on the ventral surface in front of the
cloaca on the coiled part of the posterior extremity of the male.
Arenicolous Inhabiting sand. See hypogaeic,
aquatic, edaphic, marine, rheophile, terrestrial, terricolous, xerophilous,
fossorial.
Areolate A small area, especially of cuticle,
delimited by transverse and longitudinal markings.
Arista A bristle like appendage.
Aristate Having a slender or spiny terminus.
Arrested Growth A stopping of the growth
processes.
Arrowhead-shaped See sagittate.
Ascarocollagen The non-hydrolyzed form of
ascarogelatin. It corresponds to the fiber, internocortical and fibril layers of
the cuticle.
Ascarogelatin A segregate of the cuticle of the
collagen group.
Ascarlyose The sugar 3,6-dideoxy-L-arabinohexose.
Asepsis The state or condition of being aseptic.
See sepsis.
Aseptic Free of microorganisms. See septic.
Aseptic Culture A nematode population containing a
single species only and free of contamination by all other organisms. Aseptic
population. See pure culture, pure population, agnotobiotic,
axenic, xenic, synxenic, monoxenic, dixenic, trixenic, polyxenic.
Aseptic Population
An aseptic culture.
Asexual Reproduction
Reproduction where the union of gametes is not involved.
See
sexual reproduction.
Association
Ecologically, uniform groups of strata over a large area.
Asteriform
Star-shaped. Like a star.
Atavism
Reversion to a more primitive type.
Ataxia Poor muscle coordination and
control, generally in an animal host infected by a parasite.
Athrocyte
A coelomocyte capable of absorbing foreign material from body fluids and storing
it in crystalline form.
See
coelomocyte.
Atrophy
A wasting away or arrested development.
Attacked
To be fed upon by nematodes. To become infested with nematodes.
See
invasion, infective.
Attack Population
The pathogenic nematodes per unit of substratum capable of invasion.
Attenuate
Thin, Slender, Drawn-out, Extended
Attractant
A chemical substance causing a positive migration response.
Attraction
A positive response where the mean number of migrating nematodes reaching the
plant end of a test chamber is significantly greater (at the 95 percent level of
probability) than the mean number reaching the blank end and where this
difference occurs within 3 hours in agar or 6 hours in sand.
Auricular Appendages Horseshoe-shaped cuticular forlds in the cephalic region of some nematodes, e.g. Habronematidae. See Cordons
Australian Realm The biogeographis region that encompasses Auatralia and Pacific Islands. See Holarctic Realm, Antarctric Realm.
Autapomorphy
Author
The writer of a paper, article, treatise, etc. The author's name usually
accompanies the paper to gain credit for accomplishment and to affix
responsibility.
Autochthonous Infection Infection originating from organisms, or their progeny, that are already within the or around the host; an infection acquired locally. See autoinfection.
Autogamy
Self-fertilization, the fusion of two gametes that come from one individual.
Autoinfection
The source of infection originates within body of the host. Infection from
within by progeny of previous or current parasites. Occurs in both plant and
animal hosts.
Autoinoculation
The spread of an infestation from a focus of infection to other parts of an
organism.
Autolysis
Destruction of a cell by internal agents. Self digestion of a tissue.
Automixis, Automictic Parthenogenesis Reproduction without fertilization and with a meiotic reduction division of unfertilized egg cell. Diploid number may be re-established by fusion of nucleus with polar body. See Parthenogenesis, Meiotic Parthenogenesis.
Auto-Pseudogamy A form of Pseudogamy, where male sperm is
necessary to activate oocytes but DNA is not transferred, in which females
produce a small quantity of male offspring to supply their sperm needs.
See Pseudogamy.
Autopsy
An examination and partial dissection after death.
See
postmortem, necropsy.
Autosome
A chromosome which is not a sex chromosome.
Autotomy
Self-amputation of the posterior part of the body by some nematode forms on
gaining entrance to an animal host.
Autotroph An organism with the ability to create food resources from simple compounds using the energy of the sun; a primary producer. See Heterotroph Photoautotroph, Chemoautotroph
Autotrophic Having the
ability to create complex nutritive substances from simple compounds such as
carbon dioxide and water using energy from the sun (photoautotrophic) or
from chemical reactions (chemoautotrophic). Autotrophs are primary
procucers; the energy they capture is used by consumers (heterothrophs).
See Photoautotroph, Chemoautotroph, Heterotroph.
Autotype
A specimen identified by the author as an illustration of his species
and compared with the type or cotype. Heautotype.
See
type.
Avermectin(s) A
series of 16-membered lactone derivatives of fermentation products of
Streptomyces avermitilis. They have effective anthelminthic and
insecticidal properties. See ivermectin, abamectin.
Awl-shaped
See
subulate, styliform.
Axial
Belonging to, or around, in the direction of or along an axis, in line with...
Axial Stylet A
buccal stylet aligned along the anteroposterior axis.
Axil
The angle formed between a branch or petiole and the stem from which it arises;
the cleft between two lips. See primary axil, secondary axil,
Figure 36
Axis
(pl. Axes) A straight line passing through a body about which the parts
are symmetrically arranged.
Axon, Axone
The long process of a nerve cell conducting impulses way from the cell body.
Bacillary Bands One or two
laterally situated bands of cells of the lateral cords in the esophageal region.
See
hypodermal glands.
Bacillary Layer
A non vibratile form of cilia which line the intestinal epithelium.
Bacteria Consuming
See
bacteriophagous.
Bacteriophagous
Feeding on or consuming bacteria.
See
feeding.
Bacterivores Organisms that feed on
bacteria.
Baculiform
Having the shape of a rod or staff.
Baermann Apparatus
The funnels and accessories used to implement the Baermann funnel technique.
Baermann Funnel
Technique A method of isolating nematodes from soil, screening residue, plant
tissue, or other matter where the material is placed in water and the nematodes
by their own action move out into the water, settle and are drawn off from
tubing attached to the funnel stem.
Bagging Matricidal vivipary (egg hatch within the body of
the female), also known as Endotokia Matricida.
Bag-like
See
saccate.
Ballonets
Cuticular inflations in the cephalic region assuming a swollen band shape
immediately posterior to the lips.
See
head bulb.
Banks
Groups of peripheral longitudinal muscle cells. Muscle fields.
Barcode A machine-readable representation of data by lines of different widths and spacings; for example, the DNA sequence data that characterize a species. See DNA Barcoding, DNA Metbarcoding.
Basal
Related to, located at, or forming the base.
Basal Bulb
An enlargement of the esophageal wall, muscular or glandular, at the posterior
of the esophagus.
See
cardiac bulb, bulbous, isthmus, terminal bulb, true bulb, metacorpus, posterior
bulb.
See
Figure 1,
Figure 3.
Basal Knobs
The posterior knobs of the stylet.
See
stylet knobs.
Basal Lamella
The inner-most cuticular strata which consists of a thin layer which in cross
section appears to be striated.
See
cuticular layering.
Basal Plate
The posterior radial apparatus of the cephalic framework.
Basal Ring
The posterior circular base of the cephalic framework.
See
Figure 6.
Base Pair
Batatiform
Having the shape of a sweet potato.
Bathyal Fauna
Organisms dwelling at oceanic depths of 600 to 6,000 feet, quiet water, little
to no light.
See
benthonic fauna, pelagic fauna.
Beaded
See
moniliform.
Bean-shaped
See
reniform.
Bearding
A condition of excessive root proliferation induced by nematode feeding.
Beet Sickness
A disease of sugar beets incited by Heterodera schachtii.
Beet Weariness
A disease of sugar beets incited by
Heterodera
schachtii.
Bell-shaped
See campanulate.
Benthonic Fauna
Organisms which dwell on the bottom. They are further defined as littoral,
neritic, bathyal or abyssal by depth and nature of bottom. See pelagic
fauna.
Benthos
The sea bottom; the community of organisms at the bottom of the sea..
Besom
A broom.
Besomiform
Formed or-shaped like a broom.
Biconcave
Possessing concave surfaces on opposite sides. See amphicoelous,
amphicyrtic.
Biconvex
Possessing convex surfaces on opposite sides, See amiphicyrtic,
amphicoelous.
Bicorn
With two horns. Crescentiform.
Bicornuate
Bicorn, with two pointed tips.
Bicron
One billionth of a meter (0.000,000,001).
Bifarious
Orientated or pointed in two directions.
Bifenestrate
In some species of the genus Heterodera the vulval bridge is stout and
divides the fenestra so that the semifenestrae appear to be two nearly separate
holes. See fenestrate, semifenestrate, ambifenestrate, circumfenestrate.
See
Figure 32.
Bifid
Divided into two equal parts.
Bifilar
Having two filaments or fibers.
Biflex
Bending in two directions.
Biform
Of two forms, Possessing characteristics of two forms.
Bifurcate
Divided into two branches. Forked.
Bilaterally Symmetrical
An organism in one plane with each side being approximately a mirror image of
the other. This plane usually lies anteroposteriorly and dorsoventrally.
Binding Cells
Three coelomocytic cells adjacent to the esophagus and opposite the fibril
cells, two ventrolateral and one dorsal. See coelomocytes, fibril cells.
Bioassay
Quantitative estimation of a biologically active substance by testing its effect
under standardized conditions on living organisms or the effect of one organism
upon another.
Biodiversity
The
variety and variability of life
in an ecosystem based on
variation at the genetic, species,
functional or ecosystem levels.
Biogenesis
The doctrine that living organisms are produced only from pre-existing living
organisms. See abiogenesis.
Biogeny
The evolution of organic forms considered individually (ontogeny) or tribally
(phylogeny).
Biological Control
The limiting of pathogenic nematode population through depredation by natural
enemies.
Biological Race
A segment of total species population differing in some physiological
characteristic. See biotype
Biophagous
Feeding upon living organisms or living tissue. See
feeding.
Biosis
Life. Vitality.
Biota
The fauna and flora of a region.
Biotic
Pertaining to life or the laws of animal and plant progress and evolution.
Biotope
A region of uniform environment and biotic populations.
Biotrophic Organism An organism that requires a specialized feeding site to be kept alive so that it can complete ists life cycle. See biotrophy,
Biotrophy A
relationship with the host whereby the feeding site must be kept alive to
allow the parasite to complete its life cycle.
Biotype
A subgroup of organisms which possess the same genetic characteristics. A
subdivision of a race.
Biparasitic
A parasite upon a parasite.
See
feeding.
Bipolarity
Possessing two poles.
Bisexual
The species having two sexes distinct and in separate individuals. See hermaphrodite, gonochoristid, reproduction.
Bisulcate
Having two grooves.
Bivulvarity
The occurrence of two vulvae on a single female.
Bivalents
Paired homologous chromosomes associated with synapsis.
Blackhead Disease of Bananas
A disease of banana plants incited by Radopholus similis.
Blackhead Toppling
A disease of banana plants incited by Radopholus similis.
Black Root Rot
A disease of strawberry incited by Pratylenchus penetrans,
fungi and
bacteria.
Blasting
A failure to produce fruit or seeds.
Blastocoele
The cavity of a blastula.
Blastoderm
The cell layers formed by the repeated segmentation of the blastomeres.
Blastomere
Cells produced by the first few cell divisions. A cell of the blastula.
Blastula
The early embryo having the form of a fluid-filled sphere bounded by a single
layer of cells. See gastrula.
Blind Bud
An abortive flower bud especially one due to nematode infection.
Blind End
The closed terminus of a tube or organ. See caecum.
Blinding
Destruction of a plant growing point, stem, flower or root by nematode attack.
Blind Plant
A plant with a bud or growing point killed by nematode infection.
Blister
A vesicle of cuticle or epidermis.
Blister-like
See pustule.
Bloat
A disease of onions incited by Ditylenchus dipsaci.
Bloom
The subcrystaline layer of a waxy nature found on the cysts of some
Heterodera spp.
Blunt
See obtuse.
Boat-shaped
See scaphiform.
Body
The nematode frame with its organs. The important and largest part of an organ.
as the body of the spicule.
Body Cavity The hollow within
the body which contains the internal organs. See pseudocoel.
Body Pores A series of minute depressions slightly
submedian or lateral and apparently connected with the lateral cords via small
canals.
See
caudal pores. ventromedian pores, ventrosubmedian pores, excretory pore.
Body Wall
The structural frame consisting of cuticle, hypodermis and muscle layer.
Boss A cuticular prominence on the
surface of the nematode, See Ventral Boss.
Botryoid
Resembling in shape a cluster of grapes.
Bottle-shaped
See lageniform, ampullate, ampulliform.
Boundary Layer
The cuticular stratum which is distinct only in certain instances and probably
is a condensation layer between the matrix layer and the fiber layers. See
cuticular layering.
Bounding Membrane
A thin syncytial epithelium covering the esophagus.
Bow-like
See arc, arcuate.
Brackish Water
Saltish, slightly saline.
Brain
The nerve ring.
Branched
See
ramified, ramiform.
Branched Gland A
form with outgrowths far exceeding the diameter of the cell
body
in length.
Breaking
Joint
The site of
autotomy.
Bridging
Host
The possible passing from one host to a previously unsuitable host by transition
through the intermediation of another, the bridging host.
Brier Bud
A disease of strawberry incited by Aphelenchoides fragariae. See dwarf.
Bristle Setae
Ambulatory setae apparently non-functioning glands or sensory organs acting as
organs of traction. See setae.
Bristle-shaped
See arista, setiform.
Broadcast Application
The treatment of soil with a nematicide in such a manner that the expanding
vapors form a solid carpet throughout the field. Solid application. See
row application, spot application, drench application, gas application.
Broken Striae
Non-continuous configuration lines of the perineal pattern. See partial
striae, lighter striae, intermediate striae.
Broom-shaped
See besomiform.
Brown-Leaf Disease
A disease of Asplenium nidus incited by Aphelenchoides
fragariae.
Brown Ring Disease
A disease of daffodils and hyacinth incited by Ditylenchus dipsaci.
Brown Ring Disease of Narcissus
A disease of narcissus capable of being incited by Ditylenchus dipsaci,
Aphelenchoides fragariae, A. parientinus or Aphelenchus avenae.
Buccal
Aperture
The
oral aperture.
Buccal
Capsule Sensu lato,
the combined vestibulum and buccal capsule. The stoma. Sensu
stricto,
the anterior widening of the esophageal cuticular tube often distinguished from
the lining of the latter by it more developed cuticularization. See
Figure 12.
Buccal Capsule
Cephaloboid An elongated, chambered buccal capsule in which the
cheilostom is broad and the protostom and telostom narrow while being enclosed
by esophageal musculature. See buccal capsule panagrolaimoid.
Buccal Capsule Panagrolaimoid
An elongated, chambered buccal capsule in which a short posterior part is
narrowed and surrounded by the esophageal musculature. See buccal capsule
cephaloboid.
Buccal Cavity
A buccal capsule in the broad sense
Figure 40 .
Buccal Ring
Where present, a thickened ring delimited from the beginning of the buccal
capsule by a groove.
Buccal Rod
Where present, elongated cuticular thickenings of the buccal cavity.
Buccal Rugae Folds in the wall of the
buccal cavity that provide some rigidity; rhabdions. See rhabdions.
Buccal Spear
A stomatostyle.
Buccal
Stylet
A
stomatostyle.
Buchner Funnel
A funnel with an interior perforated plate and used for vacuum filtration.
Buffered Populations
A situation existing whereby organisms affect one another in such a way that the
population density of each remains within a certain range about a mean.
Bulb Flap
One of three parts of the valvular apparatus. One in a dorsal and two in
subventral positions. See
Figure 15.
Bulb Flaps
The valvular apparatus
Bulb Teeth
The valvular apparatus.
Bulbar Valve The valvular apparatus.
Bulbiferous Having the form of a bulb.
Bulbiform Having the form of a bulb.
Bulboid Esophagus Having a cylindrical shape
anteriorly and terminated by a basal bulb. Also termed oxyuroid esophagus.
Bulbous Bulb-like.
Bulbs The one or more muscular swellings of the
esophagus. See true bulb, pseudobulb.
Bulbus The basal bulb of the esophagus.
Bulla (pl.
Bullae) A blister-like prominence near the vulval fenestra of some
Heterodera. See Figure 33.
Bullate Having a blistered or puckered form or
appearance. Having or bearing bullae. See bullae.
Burden The total number of parasites infecting an
individual.
Bursal Musculature
The arrangement of the muscles pertaining to the bursa. See musculus
costae dorsalis, musculus costerum lateralium internis, musculus bursae basalis,
musculus costae lateralis externus posterior, musculus costae lateralis externus
anterior.
Bursal
Nerve
Innervated from bipolar sensory nerve cells forming a longitudinal strand on
either side in or near the lateral cords.
Bursal Papillae
Sensory papillae that support the bursa of certain nematodes (e.g.
Rhabditidae). Their patterns and grouping are of taxonomic
signisficance. See Genital papillae,
Figure 41
Bursal Ribs
See rays,
Figure 41 .
Bursate
Having a bursa.
Byssus
Elaborately-branched polar projections of the protein membrane on eggs of some
nematodes.
Cabbagy
Plant
A disease of teasel incited by Ditylenchus dipsaci.
Caecum
(pl. Caeca) A cavity open at one
end, the blind end of a lumen or duct.
Caliciform Having
the shape of a calyx or a cup.
Calvarium
Subcuticular cephalic framework. See
Figure 1.
Camera
Lucida
An optical instrument for use with the compound microscope where by means of
prisms and mirrors a virtual image appears as if projected upon a plane surface.
Used for pencil sketching and measuring.
Campanulate
Bell-shaped.
Campanuliform
Having the shape of a bell.
Canal
A tubular channel or passage. A duct.
Cane
A thickening with a lack of ornamentation of the posterior cuticle. See helmet.
Cap Cell
The terminal cell of the ovary. The primordial germ cell. See
Figure 27.
Capitulum
A sclerotized guiding piece for the gubernaculum on the ventral cloacal surface
of some Hoplolaiminae. The manubrium of some authors. See telamon, See
Figure 20.
Alternatively, ptoposed for dorylaimoid spicules, the head of the spicule
from the proximal end to the start of the blade or lamina - the manubrium of
some authors.
Capsula
Var. of capsule.
Capsule
A receptacle or bag. A membrane or sac-like form enclosing a structure or organ.
Cardia
A muscular structure at the base of the esophagus opening into the intestine.
See esophageal-intestinal valve, cardiac valve.
Cardiac Bulb
The basal bulb of the esophagus. See cardia.
Cardiac Caecum
The esophageal caecum.
Cardiac
Esophageal Bulb
The basal bulb of the esophagus.
Cardiac Glands
Three glandular bodies located at the base of the esophagus.
Cardiac Region of the Intestine
The anterior portion of the intestine as distinguished from the prerectum.
Cardiac Valve
A thickening or complication of the esophageal lumen lining in the basal bulb.
See cardia.
Cardiac
Bulb The basal bulb.
Careen
A left dorsal cuticular dilation supported by the left
ridge and adjacent dorsal ridge of the synlophe in strongylid nematodes.
See synlophe
Carina
(pl. Carinae) An elevated ridge or keel-like structure not necessarily
pronounced or acute.
Carinate
Keeled. Having one or more longitudinal ridges.
Carnivore
A flesh eater. A predaceous nematode. See feeding.
Carnivorous
Preying or feeding on nematodes or other animals. See feeding.
Carrier
An organism bearing internally an infectious agent of disease even though no
marked symptoms are evident. See vector.
Castration
Any process which prevents the development of mature ova or sperm in the gonads.
Catabolism
The destructive processes in metabolism. The breaking down of more complex
components in protoplasm. See metabolism, anabolism.
Cation
An ion bearing a positive charge. See ion, anion.
Caudad
Toward the tail. Opposed to cephalad.
Caudal
Belonging to, or like, a tail. Situated on or near the tail.
Caudal Alae The bursa. Alae confined to the posterior part of the male
nematode body. See alae.
Caudal Appendage In mermithids, the terminal portion of the larval tail.
See terminal spine, caudal papillae.
Caudal
Caudal Flagellum A more or less filiform, long and thin elongation of the
tail of uniform diameter, or becomes a caudal thread which is pointed at its
tip.
Caudal Glands Usually three elongate unicellular cells in or near the
tail, discharging by separate ducts into a common ampulla at the spinneret.
See
Figure 7.
Caudal Papillae In mermithids, the terminal portion of the larval tail.
Caudal Papillae See submedian
caudal papillae. See
Figure 5,
Figure 18.
Caudal Pore The spinneret. The outlet of the caudal glands.
Caudal Wing The bursa.
Caudalid A single structure similar in size, morphology and body position
as the hemizonion and located slightly anteriad of the anus. A parahemizonid.
Cauliflower Disease A disease of strawberry incited by a synergistic
association of an Aphelenchoides nematode and bacterium,
Corynebacterium fascians.
Cauliflower dwarf.
Cauliflower Dwarf Cauliflower disease. See near cauliflower.
Causal Agent The parasitic organism responsible for a disease. Causal
organism.
Causal Organism
The organism that produces a given disease. Causal agent.
Causative Agent
See causal organism.
Cavate
Hollowed out.
Cavernicolous
Cave-inhabiting. See arenicolous, hypogaeic, aquatic, edaphic, marine,
rheophile, terrestrial, terricolous, xerophilus.
Cavernous
Filled with caverns. Divided into small spaces.
cbd
Cloacal body
diameter, body diamter at level of cloaca, used as a measure of distances between structures, or size of
structures, in posterior region of males. See cloacal body
diameter.
Cecum
(pl. Ceca)
An outpocketing of the intestine at the anterior end, rarely composed of twists
or loops. See caecum.
Ceiling
The maximum population density for a given set of circumstances.
Cell
The structural and functional unit of all plant and animal life. It consists of
protoplasm, a nucleus and is surrounded by a membranous wall.
Cell Body
Cell Constancy A situation in nematodes where the multiplication of cells ceases at hatching, except for the reproductive system, and growth is by enlargement of existing cells.
Cell
Grazer A nematode that withdraws the cytoplasm from a cell and then
moves to another cell; feeding from cels without requirineg
development of a nurse cell system. See biotrophic organism.
Cell Membrane
A differentially permeable membranous surface which surrounds the cell.
Cellules
End organs or terminal bodies of some coelomocytes.
Central Area
The nonstriated region anteriad of the vulva and posteriad of the cutcular
striations in Meloidogyne perineal patterns.
See
Figure 28,
Figure
29.
Centromere
That part of a chromosome to which the spindle fiber apparently attaches in
mitosis.
Centrosome
A minute protoplasmic body in the cytoplasm or nucleus that plays an important
role in mitosis.
Cephalad Towards the head.
Cephalated Having the head set off in some manner.
Cephalic Belonging to, or situated in, on or near the head. Directed toward the head.
Cephalic Adhesion Tube
A tube for sececreting
adhesive material located in the cephalic region. See adhesion
tube.
Cephalic Arches See
ribs.
Cephalic Capsule A strongly cuticularized head set off by a groove.
Cephalis Cirrus
(pl. Cirri) One of the elaborate cephalic appendages in front of the
cephalic setae.
Cephalic Crown of Sensory Organs The circular arrangement of papillae,
etc. about the oral opening See
anterior cephalic crown, posterior crown, inner circle, outer circlet.
Cephalic Framework A rigid supporting structure which provides form to
the head and axially acts as a stylet guide.
See calvarium.
See
Figure 1,
Figure 6.
Cephalic Glands Lateral glands opening near the cephalic papillae.
Cephalic Organ The head cleft.
Cephalic Papillae Papillae of the outer circlet about the mouth. See
Figure 22.
Cephalic Probolae
Six processes surrounding the mouth opening in some cephalobids and probably
extensions of the lips; distinct from
labial probolae. See labial probolae.
Cephalic Setae Setae of the outer circlet about the mouth.
See
Figure 22,
Figure 23..
Cephalic Slits
Paired pouch-shaped cephalic sense organs.
Cephalic Suture
The posterior delimitation of the cephalic capsule; the offset groove from the
body contoure..
Cephalic Tubers
Prominences located in the head in labial and cephalic positions, often
elaborately developed.
Cephalids
Structures of a highly refractive nature, biconvex in longitudinal section and
extending around the nematode body in the cephalic region. See anterior
cephalid, posterior cephalid, caudalid, hemizonid, hemizonion, parahemizonid.
Cephalization: The tendency for sensory structures and the nervous system
to be aggregated anteriorly.
Cervical
Pertaining to, belonging to or situated in, on or near the neck.
Cervical Alae
Alae confined to the "neck region" and are known only in the parasitic groups
Strongylina, Ascaridina and Spirurina.
Cervical Duct
The excretory duct.
Cervical Expansion Expansions of the cuticle in the cervical region e.g., in
Wilsonema. See cervical.
Cervical Gland
The excretory gland.
Cervical Groove
A pronounced transverse groove on the ventral surface of the cervical region, in
some forms extending to completely encircle the cervical region.
Cervical Lacuna A
space (lacuna) between the cuticle and epidermis probabl;y created by
differences in contractility of the two surfaces See Lacuna.
Cervical Papillae
Paired lateral tactile receptors situated near the nerve ring. Deirids.
Cervical Pore
The excretory pore.
Cervical Vesicle
Inflated cuticle anterior to the cervical groove.
Challange
A test of immunity to a host by exposure to parasites after specific
immunization.
Checkered
See tessellate.
Cheek
An ampulla of an amphid.
Cheeks
In Meloidogyne kikuyuensis the heavily striated overlap of perineal
cuticle on each side of the vulva. See
Figure 28.
Cheilorhabdions
The dense cuticular walls of the cheilostom. See
Figure 10.
Cheilostom
The lip cavity of the stoma, delimited anteriorly by the oral aperture
posteriorly by the protostom; the anterior region of the stoma. See protostom, telostom,
Figure 40
Cheilostome
Alternative spelling of cheilostom.
Chelate
A type of chemical compound in which a metalic atom is firmly combined with a
molecule by means of multiple chemical bonds.
Chemoautotroph
An organism that uses the energy released from inorganic chemical
compounds to build organic compounds. See Autotroph,
Photoautotroph, Heterotroph.
Chemokinesis
Stimulation of random movement induced by a chemical agency.
Chemoreceptors
Anteriorly the amphids, posteriorly the phasmids. See tactoreceptors.
Chemotropism
A movement of turning or curvature induced by a chemical stimulus. See
tropism.
Chemotaxis
A change of position toward or away from a source of chemical stimulation.
See taxis.
Chewing Plates
The valvular apparatus. See grinder,
Figure 40
Chimney
See soil chimney.
Chirotype The type specimen upon
which a manuscript name is founded. See type.
Chisel A tillage machine with one or more
soil-penetrating points that can be drawn through the soil to loosen the soil or
subsoil.
Chitin The substance composing the exoskeleton of
insects which is not equivalent to the cuticle of nematodes but is present in egg
shells of some forms.
See
cuticle.
Chitin Plates
The valvular apparatus - probably a misnomer in terms of the constituent
material of the plates .
Chords
Var. of cords,
Chorion
The
outer shell or covering of a nematode egg.
Chromatid
During prophase and metaphase of mitosis or meiosis one of the two strands prior
to separation which resulted from duplication of a chromosome. After separation
each chromatid is known as a daughter chromosome.
Chromatin
Minute granules of a nucleo-protein constituent of a cell nucleus.
Chromosome
One of the fundamental bodies into which chromatin resolves itself prior to the
mitotic or meiotic division of a cell.
Cicatrix
(pl. Cicatrices) A scar or scar-like marking, especially in mermithids.
Cicatrization Tissue
Tissue involved in the process of healing a wound.
Ciliate
Provided with cilia.
Circa-Equatorial
About the equator. About or near the middle.
Circinate
Ring-shaped.
Circlet
A small circular arrangement of structures or parts. A crown.
Circomyrian
A type of muscle cell in which the muscle fibers completely surround the
sarcoplasm. See platymyarian, coelomyarian.
Circumfenestrate
In the genera Heterodera and Globodera where the vulva is lost when fenestration occurs
by the breakdown of the thin cyst wall around the vulva leaving a circular
hatching pore. See fenestrate, semifenestrate, bifenestrate,
ambifenestrate. See Figure 30.
Circumenteric
Ring The nerve ring.
Circum-Esophageal
About or surrounding the esophagus.
Circum-Esophageal Commissure
The nerve ring.
Circum-Oral
About or surrounding the mouth.
Cirrus
(pl. Cirri) One of the elaborate cephalic appendages in front of the
cephalic setae.
Cirrus
(pl. Cirri) A slender appendage formed by the eversion of a very long
cloaca, frequently lined with spines.
Citron-shaped
Having the form of a large lemon.
Clade A branch of a cladogram that includes a single common ancestor and all of its descendants. See monophyletic.
Cladist An evolutionary biologist who studies the pattern of species relationships; one who seeka to develop natural classification systems.
Cladistics The classification of organisms according to the proportion of measurable characteristics that they have in common; assumes that the higher the proportion of characteristics that two organisms share, the more recently they diverged from a common ancestor. See apomorphy, speciation.
Cladogram A diagram showing the degree
of genetic relationship among organisms.
Classification
The systematic arrangement of organisms into groups usually based on natural
relationships. The common categories in
diminishing rank are
phylum, class, order, family, genus, species and variety.
Clavate Club-shaped.
Clavate Cells Modifications of the hypodermis which contribute to the
formation of the lips, being two in each lip and they are long cells with a
hollow interior, lamellate with expanded distal ends that fill the convexity of
the lips.
Claviform Club-shaped. Clavate.
Clay As a soil separate, the mineral soil particles less than 0.002 mm.
in diameter. As a soil textural class, soil material that contains 40 percent or
more of clay, less than 45 percent of sand, and less than 40 percent of silt.
Clay Loam Soil material that contains 27 to 40 percent of clay and 20 to
45 percent of sand.
Clear To make
the cuticle and other body parts transparent or translucent.
Clear Tail Length That portion of the tail peculiar to
some nematode larvae in which no internal bodies, structures or arrangements can
be seen. See tail terminal.
Cleavage Following fertilization, a repeated subdivision of the zygote
cytoplasm with the corresponding nuclear mitosis. See Segmentation.
Cleft The space caused by a slit, splitting, a crack, a fissure, etc.
See suture.
Clintheriform Having a shape like a plate.
CLM See Cutaneous
Larva Migrans
Cloaca In the male a common chamber lined with cuticle which receives the
products of the intestinal and reproductive tracts and empties to the exterior
via the cloacal orifice. The hind gut. See rectum.
Cloacal Body Diameter
Body diameter at level of cloaca, used as a measure of distances between
structures, or size of structures, in posterior region, of males. See
cbd, abd, vbd.
Cloacal Cuticle The cuticular linings of the cloaca which differs in some
respects from the external cuticle. See external esophageal cuticle,
rectal cuticle, vaginal cuticle.
Cloacal Evaginations Spicule pouches which secrete and lodge the
spicules.
Cloacal Orifice The opening of the cloaca
Cloacal Papillae
Tactile receptors in the region of the cloaca. See
Figure 41
Cloacal Prominence A posterior projection of the region around the
cloacal orifice in some nematode forms. The genital cone.
Clone A group of plants derived from a single plant by means of
vegetative propagation. Each individual of a clone has the same heredity, so
that in a uniform environment a clonal line of plants will respond rather
uniformly. See strain.
Clover Sickness A disease of clover incited by Ditylenchus dipsaci.
Club-shaped See clavate,
waddiform.
Clustered See agminate.
Clypeiform Having the shape of a shield. See scutate, scutiform,
escutcheon-shaped.
Coarse Root. A condition where most of the lateral roots are killed back
by nematode attack resulting in an open system of mostly the main roots.
Cobb Formula
A system of measurement utilizing decimal formula in which the measurements
stated as percentages of the total length of the nematode are made at the
specific body points as follows:
Stylet length |
Nerve ring |
Esophagus base |
Vulva |
Anus |
as % of body length |
||||
Body width at lip
region |
Body width at nerve
ring |
Body width at
esophagus base |
Body width at vulva |
Body width at anus |
Cockles Galls produced by some species of Anguina, especially
A. tritici of wheat kernels. See purples, peppercorns.
Coelomate Having a body cavity. See pseudocoelom.
Coelom
The main body cavity in which the intestine
is suspended. Surrounded entirely by tissues of mesoderm origin.
Coelomocytes Cells lying in the pseudocoelom and appear not to be part of
the general connective or isolation tissue. They apparently are of
mesenchymatous origin. See athrocytes, fixed athrocytes, phagocytes,
stellate cells, pseudocoelocytes.
Coelomyarian A type of muscle cell in which the muscle fibers are
adjacent and perpendicular to the hypodermis and extend along the sides of the
muscle cell for varying distances. See platymyarian, circomyarian. See
Figure
9.
Coevolution The process in which two or more species reciprocally affact
each other's evolution through natural selection. See speciation.
Coexistence Living together in the same place.
Cohabitants Organisms dwelling together.
Collaret A band-like cuticular extension of the cephalic region opening
anteriorly.
Collarette A posterior elongation of the annular ring.
Collum A neck or neck-like part or process.
Collum Testis A narrowing separating the testis from the deferent ducts.
Collum Uteri The constriction which separates the uterus from the vagina.
In some forms it is elongated to form the ovijector. See
Figure 24.
Colonizer-persister (Bongers' c-p) series A series of categories of nematodes based on their life history chracteristics, response to enrichment and sensitivity to environmental perturbation.
c-p1 - Nematodes with short generation time and rapid reproducive rates, respond rapidly to resource enrichment, opportunists, r-strategists.
c-p2 - Nematodes with relatively short generation time that are tolerant to environmental disturbance and resource limitation.
c-p3 - Longer generation time and greater sensitivity to disturbance.
c-p4 - Longer generation time, greater sensitivity to pollutants; usually larger-bodied.
c-p5 - Large
bodied nematodes with long generation time, low fecundity and high
sensitivity to environmental disturbance and pollution.
Colony An assemblage of nematodes living in close association, especially
of the same species and particular niche.
Column-like See rachis.
Combs Crests of cuticle which frequently bear spines.
Comb-shaped See pectinate.
Commensal A biological
interaction between two species where one species benefits while the other
is not harmed.
Commensalism The condition of different organisms living harmoniously
together.
Comminute To breakdown into minute particles. Pulverize. See
triturate, macerate.
Commissure A bundle of nerve fibers connecting ganglia.
Compatible Host-Parasite Relationship Interaction between
a nematode species and host plant that is favorable for nematode survival and
reproduction. See incompatible.
Complete Metamorphosis
The young hatch looking unlike the adult and through successive larval instars
increase in size through several molts. The pupa or resting stage is entered
where the body tissues break down and new structures for the adult arise. See
metamorphosis, incomplete metamorphosis.
Concave
Hollow. Incurved, as the inner surface of a curved surface or line.
Concavo-convex
Having one surface concave the other convex with the convexity exceeding the
concavity.
Cone
The posterior segment of a female cyst of the genus Heterodera.
Cone
A solid body having a circle for its base and terminating in an apex.
Congeneric
Of the same genus.
Conical
Cone-shaped.
Connective
The cords of nerve fibers connecting one ganglion of a nervous system with
another.
Conoid
Having the shape of a cone.
Conspecific
Of the same species. See infraspecific.
Constitutive Characters
The suite of derived characters that are comprise to the monophyly
of a clade. See clade,
monophyly.
Constriction
Said of the junction of the head and the cervical region when delimited by a
sharply pronounced groove. See depression.
See
Figure 6.
Constrictor Vulvae
Muscles which function to close the vulva. See dilator vulvae.
Contaminate
To infect or infest, with a pest an otherwise healthy organism. To pollute.
Contaminators
Individuals of the inoculum. Organisms which bear the inoculum.
Contort
To twist upon itself. To form into curves.
Contraction Swellings
Numerous deeply staining enlargements formed at intervals along a muscle
contractile fiber.
Control
The reduction, by any means, of a plant pathogenic nematode population density
which results in an economic increase in crop yield. See soil sterilant,
spectrum.
Convergence
A resemblance between individuals or structures derived from different
ancestries or origins. Lines of development coming together from diverse origins
to form similar characters. See divergence.
Convex
A surface or line curved or rounded as the exterior of a sphere or circular
form.
Coprophagous
Feeding on dung. See feeding.
Copulation The act of
sexual intercourse.
Copulatory Apparatus The copulatory armature.
Copulatory Armature The sex organs of the male
employed in the act of copulation. See spicule, gubernaculum,
supplementary papillae
Copulatory Muscles In most male nematodes
specialized transverse muscles of varying numbers extending from the lateral
cords to the subventral sides of the body, generally anterior to the cloacal
orifice. The ventral curvature of the posterior part of the body in fixed
material is caused by these muscles.
See
bursal muscles.
Copulatory Warts
Greatly enlarged genital papillae of some male nematodes.
Cord-like
See
restiform.
Cordons
Specialized, ribbon-shaped, paired bands of cephalic cuticle; horseshoe-shaped
cuticular folds or Habronematidae. See
epaulets.
Cords
Four longitudinal lines of hypodermal thickening lying on the inner side of the
hypodermis and variously termed the dorsal, lateral and ventral cords. The cords
contain the nuclei of the hypodermis. See intercordal areas.
Coriaceous
Tough, leather-like.
Cornein
The horny substance of corals and not equivalent to the cuticle of nematodes.
See, cuticle.
Corniform
An extended mucronate or pointed process like the horn of an ox.
Coronoid Beak-like
Corpus
The most anterior segment of the esophagus of cylindrical form and of moderate
width. Sometimes the base is swollen to form a bulb in such instances the corpus
may be divided into procorpus, mesocorpus and metacorpus.
Corpus Esophagi
The corpus.
Corridor
A passage or tunnel made by an animal. See gallery.
Corrugated
Wrinkled. Formed of alternate ridges and grooves.
Cortex Layer
The outer layers of the cuticle. See matrix, fiber layers, cuticular
layering.
Cortical
Consisting of, or belonging to the cortex.
Coryogamy
Var. of koriogamy.
Cosmopolitan
Common everywhere. Widely distributed. Found in most areas of the world. See
ecumenical.
Cospeciation
A form of coevolution
in which speciation of one species dictates that of another; it is most
commonly studied in host-parasite relationships.
howqever, host-parasite phylogenies may be
altered by host switching, extinction, independent speciation, and other
ecological events, so that cospeciation harder to detect. See coevolution, speciation,
Fahrenholz's rule, phylogeny.
Costa
(pl. Costae) A rib or rib-like
structure.
Costate
Having the appearance, structure or form of a rib or ribs.
Cotype
Any one of all the specimens available when a species is named, hence the type
equals the sum of the cotypes. See type.
Coupled Annules
Adjoining annules are inserted into one another providing added rigidly and
allowing elasticity.
Crenate
Having a margin formed of rounded scallops.
Crenation
A rounded projection.
Crenature
A rounded projection, also, the indentation between crenations.
Crenulate
Minutely crenate.
Crescent
Sickle-shaped, like the new moon with convex and concave edges.
Crescentiform
Having the shape of a crescent.
Crest
A ridge or linear prominence. See carinate.
Cristate
Having a prominent crest. Crested.
Cristiform
In the shape of a ridge or crest.
Cribriform
Perforated like a sieve.
Crimp
A pathological condition incited by nematodes where plant parts are crinkled,
twisted and distorted.
Crimp
A disease of strawberry incited by Aphelenchoides fragariae.
Crop Rotation
The sequence of plants grown in a particular field.
Cross Breeding
The mating of two varieties of the same species. To hybridize.
Cross Infection
The infestation of another individual of the same species.
Cross Section
A transverse cut. A cut of an organism or thing at right angles to the
longitudinal axis.
Crowding Effect
A situation where the average size of individuals is reduced in multiple
infestations.
Crown
A circular structure or process or arrangement of such structures or processes
generally at or near the summit of an organ or part. See corona, circlet.
Cruciate
Cross-shaped.
Cruciform
Cross-shaped.
Crumb
An aggregate of soil particles.
Crura The legs of an animal, or the legs of a structure, e.g. a gubernaculum with two parallel guiding rods or rails. See gubernaculum.
Crustformeria
A specialized region ibetween the ovary and uterus where the egg shell is
deposited.
Cuff
A widened glide path of the gubernaculum to help guide the spicule.
Cuirass
A protective covering such as the cuticle.
Cuirasse
A helmet-like appearance of the cuticle of the head.
Cultural Services Ecosystem services that provide
non-material benefits, including recreational opportunities, aesthetic
experiences and spiritual enrichment of humans.
Cuneiform
Wedge-shaped. See sphenoid.
Cup-shaped
See cupuliform, cyathiform.
Cupuliform
Having the shape of a cup. Cyathiform.
Curds
Dried masses of Ditylenchus myceliophagus and others similar to nematode
wool.
Curly Leaf
A disease of strawberry incited by Aphelenchoides fragariae. See dwarf,
crimp.
Curly Tip
A condition where nematode feeding near a root tip causes retardation of growth
and the elongation on one side results in a curling effect.
Cusp
A pointed process. See pointed.
Cuspate
Pointed.
Cuspidate
Terminating in an acute point.
Cutaneous Larva Migrans (CLM) A
human skin infection in which humans are
accidental hosts for
larvae of various species of hookworm (family Ancylostomatidae) that are
parasites of wild and domestic animals. See Visceral Larva Migrans, Neural
Larva Migrans.
Cuticula
Cuticle.
Cuticle
The noncellular external covering of the nematode and apparently connective
tissue of the hypodermis. The cuticle lines the natural opening of the body i.e.
the oral cavity, the anal aperture, the vulva, the vagina, the lumen of the
esophagus, the rectum, the cervical pore, and the cuticular ampulla of the
cervical pore.
See
hard cuticle, soft cuticle.
Cuticular Adornments
Cuticular ornamentations.
Cuticular Framework
See
frame work.
Cuticular Layering
Structural strata of which the cuticle is composed.
See
external cortical layer, internal cortical layer, fibrillar layer, matrix layer,
boundary layer, external fiber layer, basal lamella.
Cuticular Ornamentation
Markings of any type on the cuticle.
Cuticular Protuberance
Any of a number of modifications of the cuticle, i.e. probollae.
Cuticular Rods
In the lip region of some forms the stylet is surrounded by short longitudinal
cuticularized rods forming a kind of guiding sheath. Modified cheilorhabdions.
Cuticular Wing
A segment of a complicated Tylencholaiminae stylet.
Cuticularized
Formed of cuticle.
Cutin
A compound related to cellulose and not equivalent to the cuticle of nematodes.
See
cuticle.
Cutting Organ
See
onchia, odontia, jaws, denticle.
Cyathiform
Concave. Cup-shaped. Cupuliform.
Cylindrical
Esophagus
Of a large diameter and uniform in width throughout. Characteristic of rapacious
nematodes.
Cylindrus The expanded basal portion oof the dorylaimid
esophagus (pharynx)
Cyst
At maturity the body wall of the Heterodera female thickens, becomes
resistant to decay, and turns brown as the worm dies, resulting in a protective
shell for the eggs and is termed a cyst.
Cyst Cone
The conical perineal region of cyst- forming nematodes.
Cyst-Forming Nematode
Any species of the genera Globodera
and Heterodera.
Cytogenetics
The study of the structural basis of heredity and variation.
Cytokinesis
The changes affecting cytoplasm of a cell undergoing mitosis, meiosis and
fertilization.
See
karyokinesis
Cytology
The study of the structure, organic processes, functions, etc., of cells.
Cytolysis
The dissolution or destruction of cells.
Cytophagous
Feeding on cells. See feeding.
Cytoplasm
The protoplasm of a cell exclusive of the nucleus and cell wall.
Damage
Year The growing
season in which a crop sustained injury due to nematode parasitism.
Dauer Larvae A quiescent stage entered by larvae while enclosed in the
cast cuticle of the previous stage.
Decant To gently pour off a liquid in such a manner as not to roil or
disturb that
remaining.
Decantation-Sieving Method. The gravity-screening method of nematode
isolation.
Decapitate
To remove the head. To behead, Decollate.
Decay
A putrefactive change. The ultimate catabolic state. To rot.
Decline
A condition of progressive deterioration of tree foliage and branches.
Decoction
A condensing especially by steeping. An extract obtained by boiling.
Defecate
To void excrement.
Definitive
Complete. Fully developed.
Definitive Home
The site of permanent attachment or lodging of parasitic nematodes after a
period of larval wandering or migration.
Definitive Host
The host in which the sexual life of a parasite takes place. See
primary host, secondary host, intermediate host.
Degenerate Esophagus
An esophageal region showing little or no evidence of its triradiate character
or muscular tissue.
DEGO Dorsal esophageal gland opening into esophageal lumen,
the position is taxonomically important, especially in the order Tylenchida. See dorsal esophageal gland orifice,
DGO,
DPGO.
Note: esophagus as alternate terminiology for pharynx.
Degeneration
Breakdown of the tissues of the internal organs. See devolution.
Dehydration
The removal of water, See desiccation, exsiccate.
Deirids
Exceptionally large cervical papillae. Lateral tactile receptors situated in the
lateral field near
the
nerve ring.
Delicate
Of slight or thin characteristics.
Deltoid
Triangular in shape.
De Man Formulae
A system of measurement used in identification based on
proportional morphometrics. Originally developed by De Man but other parameters
have been added by subsequent users, some useful for specific taxa.
n =
number of specimens
L = body length in mm or µm
a =
(overall body length)/(greatest body
width (generally at the vulva))
b =
(overall body length)/(esophagus length
from the lips to the esophageal intestinal valve)
b' =
(overall body length)/(esophagus length
from the lips to end of the esophageal glands)
c =
(overall body length)/(length of tail
(anus to tail terminus))
o = (distance of dorsal esophageal gland opening from stylet knobs x 100)/(length of stylet)
p =
(distance of phasmid(when
not erratic) from anus x 100)/( length of tail)
pa = (distance of anterior phasmid (when erratic) from lips x 100)/(overall body length)
pp
= (distance of posterior
phasmid (when erratic) from lips x 100)/(overall
body length)
G1 =
(overall length of anterior ovary from
vulva x 100)/(overall body length)
G2 =
(overall length of posterior ovary from
vulva x 100)/( overall body length)
V =
(distance of vulva from the lips x
100)/(overall body length)
stylet
extension (odontophore) length in µm
gubernaculurn length in µm
spicule length in µm
capitulum length in µm
R = total number of body annules
Rex = number of body annules between anterior and excretory pore
RV = number of body annules between vulva and tail tip
Ran = number of body annules between anus and tail tip
RVan = number of body annules between vulva and
anus
For example (the range is given within the parentheses, the % sign is frequently
omitted):
Measurements:
(n = 20 females) L = l .17 mm (0.194 1.37 mm); a = 31.3 (26.7-34.6); b = 8.5
(7.9-10.0); b' = 6.3 (5.4-7.5); c = 69 (53.91); o = 14% (10-17%); P = 45%
(42.47%): G1 = 36.2% (28.2-48.7%); G2 = 33.1 % (25.5-38.5 %); V = 56.5 %
(54-61 %); stylet=43.l (38.2-44.
5 µm). (n = 16 males) L =
9.6
mm (0.74-1. 16 mm); a = 29.2 (26.3- 36.4); b = 7.7 (6.9-8.5); b'
= 6.9.
(5.4-7.4); c = 34 (29-37); o = l3 %, (10-13 %); P = 42 % (41.1- 46 %);T =
38 % (34-54 %); stylet = 41.4 µm (39.4-43.3 µm);
spicules=48 µm (42-52 µm);
gubernaculum = 24.7 (20.4-28.6 µm); capitulum
= 18.8 µm (16-20.2 µm).
DeManian System
A system of vessels connecting the intestine and uteri with one
another and posteriorly with the exterior. Also used for
a group of tubes near the anus of certain female nematodes that secrete a sticky
substance which protects the eggs or functions during copulation.
De Man Indices
See De Man Formulae.
Demarcation
Marked by bounds. Delimited. A separation.
Dendrites
Branching cytoplasmic projections of a nerve having synapses with axons of other
nerve cells.
Denematize
To divest of nematodes.
Dentate
Bearing teeth. See edentate.
Denticle
A small tooth or projection.
Denticulate
Having minute tooth-like projections.
Dentiform
Having the shape of a tooth.
Dentigenous Ridges
Elevations bearing small tooth like projections.
Dentoid
Tooth-shaped.
Deoxyribonucleic Acid See DNA.
Depauperate Lacking in abundance or variety of species in an ecosystem.
Dependent Hatching
The need for an external stimulus for hatching to be affected.
Depresssion
Said of the junction of the head and the cervical region when delimited by a
more or less broad hollow. See constriction.
Depressor Ani
The H-shaped muscle which serves to dilate the rectum and elevate the posterior
lip of the anus thus permitting defecation.
Derived Character A trait that arose in the most recent common ancestor of a particular lineage and was passed along to its descendants. See Primitive Character.
Dermal LD50
The dosage of a chemical, based on the mass of the affected organism, at
which 50% of the target organisms are killed when the material is in contact
with the skin; for example, 10 mg of chemical per Kg of target organism
tissue. See Lethal Dosage.
Desiccate
To dry up. See dehydration. Exsiccate.
Desiccation
The state or condition of being dried up.
Desmen A ring of sedimentary material, cemented (by desmos) on the outer surface of a nematode of the family Desmoscolecidae; the body is covered by desmen rings.
Desmos A cement material that holds together the
sedimentary particles comprising a desmen.
Detritophagous
Feeding on detritus. See feeding.
Detritus
The disintegration products of decomposition.
Deutoplasm
The food plasm of an ovum. The yolk.
Deutoplasmatic Inclusion
A granule or crystal in the yolk.
Devoid
Lacking something. Not bearing something.
Devolution
Retrograde development. Degeneration.
Dew Point
The temperature at which the liquefaction of a vapor begins. Usually the term is
applied to condensation of moisture from water vapor in the atmosphere.
DGO Dorsal gland opening into esophageal lumen or
stoma, the position is taxonomically important, especially in the
Tylenchida. See DEGO, DPGO.
Dignosis
(pl. Diagnoses) A critical scrutiny or presentation of those characters
which differentiate the species (or other group) from its closest relatives.
Didelphic
Having two ovaries. See amphidelphic, monodelphic, prodelphic,
opisthodelphic, polydelphic, reproduction. See
Figure 27.
Didymous
In pairs. Two fold.
Dieback
A condition of progressive necrosis of branch terminals of trees and other
plants.
Differentiation
The diagnosis of a taxon.
Differentiation
The act or process of characterizing or making different. Changing from general
to special characters. Specialization.
Diffusate
A compound, especially a stimulatory one, which spreads through the substratum
from the point of origin. See root diffusate, leachate.
Digestion
The process of preparing food by chemical breakdown for absorption and
assimilation.
Digestive Diverticula
Intestinal caecum.
Digger Hooks
Modified lip structures of the genus Diploscapter.
Digitate
Finger-like in shape or divided into finger-like processes.
Digitiform
Having the shape of a finger.
Digonic Female
A digonic hermaphrodite. See reproduction.
Digonic Hermaphrodite
A situation where sperm and ova are produced in different gonads of the same
individual. See syngonic female, reproduction.
Diheteroxenous
Development The requirement of a parasite for two hosts to complete
its developmental cycle. See heteroxenous development, dixenous
development, triheteroxenous development, trixenous development.
Dilatator Ani
The dilator ani.
DilatorAni
The muscle which expands the anus.
Dilator Vulvae
Vulvar muscles inserted ventrolaterally in the hypodermis and functions to open
the vulva. See vulvar muscles.
See Figure24.
Diluent
A diluting agent.
Dimorphic
Individuals of the same species occurring in two distinct forms i.e. male and
female. See heteromorphic, monomorphic, polymorphic, reproduction.
Dioecious
Existing as separate and distinct male and female. See dimorphic,
reproduction.
Dioecy A mating system involving males and females. See
androdioecy, trioecy.
Diorchic
Having two testes. See monorchic, reproduction.
Diovarial. See Didelphic.
Diplogasteroid Esophagus
Having a muscular cylinder anteriorly followed by a median bulb, terminated by a
glandular base.
Diploid
Having a double (2n) number of chromosomes. See haploid.
Direct Cycle
Eggs of parasitic parents hatch into free-living larvae which develop directly
into parasitic forms. Homogonic cycle. See heterogonic cycle.
Direct
Straight growth to maturity through four successive molts.
Disc
Plate-like with a flat circular surface.
Disciform
Having the shape of a plate or disc.
Discoid
Having a shape like a round plate. Disk- like.
Discoloration
Changed to a different color. Stained. Disease A condition produced by some
factor in which any part of a ]iving organism is abnormal.
See
injury.
Dissemination
The spread of infectious agents by any means.
Distad
Toward the distal end.
Distal
Remote from the point of origin or attachment.
See
proximal.
Distal Tubes
The marginal tubes of esophageal radii.
See
Figure 13.
Distention
The act or state of extending or stretching.
Diurnal Rhythm
Having a 24 hour periodic cycle. Divergence The development of dissimilarity in
forms from a common ancestor.
See
convergence.
Divergent
Extended from a point in different directions or the trends of development.
Diversity The condition of being comprised of different types of entities, such as apecies. Diversity is greatest when all species present are equally abundant. See abundance, true diversity.
Diversity Indices Measures or indicators of the degree of diversity. See true diversity.
Diversity-weighted Abundance
A product of diversity and abundance which recognizes that both may
contribute to ecosystem services. See diversity, abundance,
ecosystem services.
Diverticulum
(pl. Diverticula) A blind tube or sac off from a cavity or canal.
See
caecum.
Divided
Parted. Disunited.
See
partite, tripartite.
Dixenic
Pertaining to the rearing of an organism with two known species of associated
organisms.
See
gnotobiotic, agnotobiotic, xenic, axenic. synxenic, trixenic, polyxenic.
Dixenous Development.
The requirement
of a parasite for two hosts to complete its developmental cycle. See
heteroxenous development, diheteroxanous development, triheteroxenous
development, trixenous development.
DNA
DNA Barcoding a taxonomic method utilizing a short genetic marker in an organism's DNA, represented in barcode format, to identify the organismt as belonging to a particular species. See Barcode.
DNA Metabarcoding The use of barcoding to identify organisms from a sample containing DNA from an assemblage of organisms.
DNA Polymerase An enzyme that catalyzes production of DNA molecules from nucleoside triphosphates. See Polymeras Chain Reaction, PCR, RNA Polymerase.
Dormancy
The dormant state.
Dormant
Inactivation as if in sleep. Quiescent
See
aestivation.
Dorsad
In the direction of the dorsum. Toward the dorsal aspect.
See
ventrad.
Dorsal
The back side aspect of a nematode. Belonging to the back side.
See
ventral, dorsum
See
Figure 22,
Figure 23.,
Figure 28,
Figure
29.
Dorsal Cord
The dorsal line of the four longitudinal lines of thickening on the inner side
of the hypodermis.
See
cords, ventral cord, lateral cords.
See
Figure 21.
Dorsal Cone
A prominent projection on the roof of the buccal capsule which contains the
terminal orifice of the dorsal esophageal gland.
Dorsal Depressor Ani Muscle
See
depressor ani.
Dorsal Esophageal
Gland The dorsal most of the three esophageal glands. Note:
esophagus as alternate terminiology for pharynx.
Dorsal Esophageal Gland Orifice
The aperture of the duct from the dorsal esophageal gland into the lumen of the
esophagus.
See
esophageal glands.
See
Figure 1.
Dorsal Gland Orifice
The dorsal esophageal gland orifice.
Dorsal Gutter
A longitudinal thickening in the in the roof of the buccal capsule which
contains the terminal orifice of the dorsal esophageal gland.
Dorsal Lobe
In males of some nematode forms the terminal section of the bursa lying between
the dorsal rays.
Dorsal Nerve
A nerve that originates from the mid-dorsal region of the nerve ring, extends
posteriorly in the dorsal cord as a motor nerve devoid of, or poor in, ganglion
cells.
Dorsal Pharyngeal
Gland The dorsal most of the three pharyngeal glands. Note:
pharynx as alternate terminiology for esophagus.
Dorsal Pharyngeal Gland Orifice
The aperture of the duct from the dorsal pharyngeal gland into the lumen of the
pharynx
See
esophageal glands.
See
Figure 1.
Dorsal Rays
The paired genital papillae of the dorsal lobe of the bursa.
Dorsal Somatic Nerve
The dorsal nerve.
Dorsolateral
The position on the nematode body situated 300 laterally from the dorsomedian
line and perpendicular to the anteroposterior axis Subdorsal.
See
position.
See
Figure 22,
Figure
23.
Dorsolateral Muscle Fields
A segment of the dorsosubmedian muscle field being delineated by a lateral cord
and a subnicdian thickening of the hypodermis.
See
dorsosubmedian muscle field, ventrosubmedian muscle fields.
See
Figure 21.
Dorsolateral Nerves
Nerves that arise between the dorsal and lateral nerves.
Dorsomedian
The true
middle line on the back side of an individual.
Dorsorectal Ganglion
A ganglion which gives rise to a medium caudal nerve extending posteriad to the
tail.
Dorsorectal Nerve
A nerve that extends from the rectal commissure to the rectum.
Dorsosubmedian Muscle Fields
The somatic muscle bounded by the dorsal cord and the lateral cords.
See
ventrosubmedian muscle fields, subdorsal muscle fields, dorsolateral muscle
fields, ventrolateral muscle fields, subventral muscle fields,
See
Figure 21.
Dorsoventral
An imaginary line extending from the dorsal to ventral side. The dorsoventral
axis. The median line.
See
position.
Dorsum
(pl. Dorsa) The back.
See
venter.
Dorylaimoid Esophagus
Having the shape of a long- necked bottle, being slender and thin at the
anterior end then expanding towards the cardia.
Double Eggs
Nematode ova of an abnormally large size and generally nonviable.
Double Guiding Ring
A condition where the guiding sheath of the stylet has two thickened rings of
cuticle.
See
Figure 2.
DPGO Dorsal pharyngeal gland opening intopharyngeal lumen,
the position is taxonomically important, especially in the order Tylenchida. See dorsal esophageal gland orifice,
DGO, dorsal pharyngeal gland oorifice, DEGO. Note: pharynx as alternate
terminiology for esophagus.
Drench
To wet thoroughly especially with a solution. To soak. To saturate.
Drench Application
The treatment of soil or other material with a nematicide as a water emulsion or
mixture.
See
broadcast application, gas application, row application.
Drop-like
See
guttate.
Duct
A tube or channel, especially one for conveying the secretions of a gland.
See
Figure 1.
Ductule
A small duct.
Ductus
A duct.
Ductus Ejaculatoris
A duct formed by the union of the vas deferens and the duct of the seminal
vesic1e for conveying the sperm to the spicula.
Ductus Masculinus
The efferent duct.
Ductus Spermatic
The vas deferens.
Duff
The matted, partly decomposed organic surface layer of forested soils.
Dung
Consuming
See
coprophagous.
Dwarf
Nanism
Dwarf
A disease condition of plants incited by
Aphelenchoides
spp. with varying degrees of deformation of stems, leaves, flowers and buds
which may remain rudimentary. Often termed spring dwarf or summer dwarf.
Dwarf Plant
Reduced in stature or form but retaining the same proportions as a normal plant.
See
stunted plant.
Dystrophy
Nutrition faulty or imperfect.
Ecdysis
(pl. Ecdyses) The act of shedding the outer cuticular layer. A molt.
See
instar.
Eclosion
The act or process of hatching from the egg.
Eco-exergy
The
chemical energy stored in organic matter and the genetic information
embodied in biomass of living organisms, providing an indicator of ecosystem
complexity and strucure.
See ecosystem.
Ecology
The relations between organisms and their environment. The reactions of
organisms to the conditions of their existence.
Ecosystem An assemblage of living organisms interacting as a system in conjunction with each other and with their abiotic environment.
Ecosystem Function The biological, geochemical and physical processes that take place in an ecosystem. See ecosystem services.
Ecosystem Sevices The functions of the ecosystem, derived from the activities of living organisms in conjunction with their environment, that enable life on Planet Earth. They may be grouped into four broad categories: See Supporting Services, Provisioning Services, Regulating Services and Cultural Services.
Ecotone
Transition areas between different communities occupied by mixed and fluctuating
populations.
Ectoferment
Saliva of extraoral digestion.
Ectoparasite
An organism living upon and/or feeding on the host from the exterior.
See
endoparasite.
Ectopore
The excretory pore.
Ecumenical
Worldwide in extent. General. Cosmopolitan.
Edaphic
Relating to, or belonging to the soil.
See
arenicolous, aquatic, hypogaeic, marine, rheophile, terrestrial,
terricolous, xerophilous.
Edentate Toothless. See dentate.
Eelworm A vernacular term for any individual of the phylum Nematoda,
especially for free-living and plant-parasitic forms. See nema, nematode,
roundworm, threadworm.
Eelworm Disease of Hyacinth A disease condition of hyacinth incited by
Ditylenchus dipsaci.
Effective Number of Species
A measure of species diversity. See true diversity.
Effector A molecule that
selectively binds to a protein and regulates its biological activity. It may
increase or decrease enxyme activity, gene expression or cell signalling.
Molecules secreted by the esophageal glands of plant-feediong nematodes that
affect the development or function of plant cells are examples of effectors.
Efferent Bearing or conducting away from an organ or position. See
afferent.
Efferent Duct The conveying duct of the male connecting the testis with
the rectum. It is composed of the vas deferens, ductus ejaculatorius, vesicula
seminalis and the distal sphincter.
Effete No longer capable of producing ova. Egg The reproductive body
produced by the female. An ovum.
Egg Chamber A reservoir in the ovijector.
Egg Mass In the broad sense, the gravid female, Meloidogyne spp.
with her external matrix containing extruded eggs. In the narrow sense the
extruded eggs contained within the matrix. See external egg mass,
internal egg mass.
Egg Sac An egg mass.
Eight-shaped (8-Shaped) Structure A panduriform structure surrounding the
vestibule extension at the approximate latitude of the cephalic constriction.
See lemniscate.
Ejaculatory Duct The ductus ejaculatorius.
Ellipsoidal Elliptical. Oval.
Elliptical-shaped like an ellipse. Oblong-oval.
Elongate To lengthen. To stretch out.
Elutriator An apparatus for washing soil for the extraction of nematodes.
See Seinhorst apparatus.
Elutriator Apparatus An apparatus for quantitative extraction of
nematodes from soil.
Embedded Buccal Capsule A condition when the buccal capsule is totally
surrounded by the esophageal musculature.
Embryo An organism in the early stages of development. The organism
before hatching from the egg.
Embryonated Said of an egg containing an embryo or larva. See ovic
embryo, juvenile.
Embryonic Found in, or belonging to the embryo. Incipient and
rudimentary.
Embryonic Development Growth and maturation of the egg.
Emend To free from a defect or a deficit.
Encyst To become enclosed in a cyst, capsule, molted cuticle or by
structures which function as such. See ensheath.
End Bulb The basal bulb.
Endemic Native to a certain region. Indigenous. See exotic.
Endocuticle A section of homogenous material internal to the exocuticle.
A 5-banded layer in some
Heterodera.
Endogenous Nemin Nemin obtained from the whole of the nematode.
See nemin.
Endogenous Organis Matter
Organic material providing a source of carbon and energy that is
produced within a field or ecosystem. See Exogenous Organic Matter.
Endoparasite An organism living within and feeding on the host. See
ectoparasite.
End Organs The nerve endings of the amphidial nerve coiled within the
amphidial pouch. Fibrillar terminals.
End Organs Phagocytic structures of some coelomocytes. See
terminal bodies, cellules.
Endosymbiont An
organism that lives inside or on the surface of another organism, forming a
symbiotic relationship.
Endosymbiosis Two organisms living together in symbiosis, with one inside the other. See symbiosis
Endotokia Matricida The failure of normally oviparous nematodes to
deposit their eggs which may then accumulate, continue to develop, and hatch within the
female body. (But see Taylor, Netscher, Chen and Caswell-Chen, 2003)
Enemy Crops A control technique where a nonhost crop is planted on Heterodera infested land. These crops produce active root diffusates induce
hatching but do not support nematode development. See trap crops.
Ensate Sword-shaped. Having two edges, broad based and tapering to a
point.
Ensheathed A situation where a molted cuticle remains as a protective
covering investing the larva thus affording protection against adverse
conditions. Encysted.
Ensiform Sword-shaped. Having two edges, broad based and tapering to a
point.
Entad An inward extension from without.
Enteric Belonging to, or relating to the digestive tract or enteron.
Enterobiasis A
general term for pinworm infections of mammalian digestive systems.
Enteron The digestive tract as a whole.
Entomopathogenic Nematode
A nematode that, either by direct feeding or by vectoring toxic
bacteria, cause harm or death to an insect.
Entoparasite An internal parasite. Endoparasite.
Entrails Viscera, Internal organs.
Entropy The degree
of disorder, randomness or chaos in a system, for example, aggregates of
organisms in a community or food web, resulting in reduction of functions or
services of the system. See Negentropy
Environment All external conditions that may act upon an organism or
thing to influence its development or survival.
Epaulets Specialized, ribbon-shaped, paired bands of cephalic cuticle.
See cordons.
Epibiotic Living
on the surface of a host organism, either in a perasitic or non-parasitic
commensal association. See commensalism
Epiblast The outer layer of the blastoderm. See hypoblast.
Epidermal Fields The cords.
Epidermis The outer cylinder of cells consisting of a single layer of
epithelium which secretes the cuticle. The hypodermis.
Epiptygma A vulval flap.
Epistrate a general term for microorganisms growing on the surface of differnt substrates, e.g., algae and bacteria growing on sedimet on a river or ocean bottom.
Epistratum The
upper layer.
Epizoite A sedentary nonparasitic animal living attached to another
animal.
Epizootic A disease affecting many animals of the same kind
simultaneously. Epidemic.
EPN
Entomopathogenic nematode.
Equatorial Situated at the middle or central region of a body or part.
See midbody.
Eradicate Complete destruction especially of a population.
Eructation The ejection of contents from the intestine via the mouth.
Escutcheon-shaped
Having the shape of a shield.
See
scutate, scutiform, clypeiform.
Esophageal Bulb
Any of the several enlargements of the esophageal wall, muscular or glandular.
See
cardiac bulb, bulbus, terminal bulb, basal bulb, true bulb, metacorpus,
posterior
bulb.
Esophageal Caucus
A blind diverticulum at the posterior part of the esophagus.
Esophageal Collar
Esophageal tissue which surrounds the stoma.
Esophageal Cuticle
The cuticular lining of the esophagus lumen which differs in some respects from
the external cuticle.
See
external cuticle, rectal cuticle, cloacal cuticle, vaginal cuticle.
Esophageal Cylinder
The esophagus proper.
Esophageal Funnel
A situation anterior in which the tips of the esophageal sectors are parted
infundibuliformly. See
infundibuliform.
Esophogeal Gland Nuclei and Orifices The position of the nuclei and orifices of the five esophageal glands of the Dorylaimina may be described in relation to the length of the esophagus:
DO: orifice of dorsal gland (e.g. 51-55 %)
DN: dorsal gland nucleus at center of nucleolus (e.g. 54-58 %).
S1O: orifice of the first pair of ventrosublateral glands (e.g. 65-68%).
S1N1: anterior nucleus of the first pair of ventrosublateral glands (e.g. 69-72 %).
S1N2: posterior nucleus of the first pair of ventrosublateral glands (e.g. 70-74 %).
S2O: orifice of the second pair of ventrosublateral glands (e.g. 84-86 %).
S2N1: anterior nucleus of the second pair of ventrosublateral glands (e.g. 84-86 %).
S2N2: posterior nucleus of the second pair of ventrosublateral glands (e.g. 88-90 %).
K: Distance DN-S1N1 as a percentage of distance DN-S1N2.
K':
Distance DO-S1O as a percentage of DOS2O.
Esophageal Glands
Elongated glands of simple or branched tubules located in the esophageal
sectors, the secretions of which are apparently of an enzymatic nature, one
gland being situated dorsal and two submedian or modified.
See
salivary glands, pharyngeal glands.
See
Figure 3.
Esophageal Glands Enclosed
A situation where the salivary glands are contained within the esophagus body
proper.
Esophageal-Intestinal Valve
A muscular structure at the base of the esophagus opening into the intestine.
See
cardia.
See
Figure 3,
Figure 15.
Esophageal Lumen
The cavity bounded by the esophageal musculature serving to convey food from the
stoma to the intestine.
See
Figure 3,
Figure 13,
Figure 15.
Esophageal Nerve Ring
The nerve ring.
Esophageal Radii
Triradiate expansion folds of the esophageal lumen which may converge terminally
or become rounded to form marginal tubes.
See
Figure 13.
Esophageal Sectors
The three sections of the esophageal musculature as divided by the esophageal
radii, one dorsal and two ventrolateral
See
Figure 13.
Esophageal Sleeve See
esophageal collar
Esophago-Intestinal Cells The
esophageal-intestinal valve.
Esophago-Intestinal Junction The
esophageal-intestinal value.
Esophago-Intestinal Valve Var. of
esophageal-intestinal valve.
Esophagus The muscular tube that leads from the
stoma or stylet base to the intestine. Alternate terminology for pharynx. The pharynx, in a strict sense since a
true esophagus is lacking
in Nematoda.
See
Figure 1.
Esophagus Degenerate
A situation where the esophageal region shows little or no evidence of its
triradiate character or musculature.
Etiological Agent
The parasite inciting a disease in a plant or animal.
Etiology
Inquiry into the causes of a disease.
Etymology The origin and derivation of
the genus and species name of an organism, or of names applied at other
taxonomic levels.
Euploid
Having an exact multiple of the haploid chromosome number.
See
aneuploid, haploid, monoploid, heteroploid, hyperploid, polyploid.
Euryhaline
Capable of tolerating a wide variation of osmotic pressure in an environment.
See
Stenohaline.
Eurystomatous
Descriptive of diplogasterid nematodes with a wide stoma,
with teeth, and usually associated with predatory behavior..
Eutrophic
Being in a well nourished state.
Evaginate
To turn inside out or to cause an internal structure to protrude or project
externally.
Eversible
Capable of being turned outward or inside out. Capable of being everted.
Evert
To turn inside out.
Eviscerate
To disembowel. To gut.
Excrescence
An appendage or outgrowth. A protuberance.
See
process.
Excrete
To void waste products from the body.
Excretory Duct
A tube or canal by which the excretory products of the excretory system are
conveyed to the exterior via the excretory pore.
Excretory Pore
A ventral opening in the cuticle by which the waste products of the excretory
system are emitted to the exterior. Cervical pore.
See
Figure 1.
Excretory Sinus
A common cavity of the excretory ducts communicating to the exterior by the
excretory pore via a cuticle-lined reservoir or an elongated terminal duct.
Excretory System
All the structures concerned in ridding the body of waste products other than
the intestine.
Excurrent
Attenuate. Narrowly elongated.
Exocuticle
The cortical layer, fiber layer, fibrillar layer, inner matrix and boundary
layer of the cuticle.
Exogenous Organis Matter Organic material imported as a
source of carbon and energy from outside a field or ecosystem. See
Endogenous Organic Matter.
Exotic
Introduced into the locale. Not native,
See
endemic.
Exsiccate
To dry up.
See
dehydration. desiccate.
External Amphid
The cuticular manifestation of the amphid.
External Circlet
The combined cephalic crown and the outer labial crown by forward migration of
the former. The outer circlet.
External Cortical Layer
The outermost stratum of the cuticle which is subdivisible into parts, the outer
denser part and the inner less dense and thinner part.
See
cuticular layering.
External Cuticle
The cuticle covering the exterior of the nematode body which differs in some
respects from that which lines parts of the digestive tract and vagina. See
esophageal cuticle, rectal cuticle,
cloacal
cuticle, vaginal cuticle.
External Egg Mass
Eggs of Meloidogyne
deposited in matrix outside the gall tissue. See egg mass, internal egg
mass.
External Genital Armature The bursa.
External Parasite An
ectoparasite.
External Protractor Spiculi
Muscles extending posteriorly
from the external side of the spicule
head.
Extogenous Capable of growth outside of the body.
Extorted
Turned or twisted away from the median axis. See
intorted.
Extracellular Digestion
Digestion of food within the intestinal cavity
allowing the simpler molecules to be absorbed by the cells.
See predigestion,
extraoral digestion, intracellular digestion.
Extrados
The exterior curve of an arch. See intrados.
Extraintestinal Digestion
Extraoral digestion.
Extraoral Beyond or outside of the mouth.
Extraoral Digestion The digestion or partial
digestion of food outside of the body (for instance, the salivary injection into
cell protoplasm prior to ingestion).
See predigestion,
extracellular digestion, intracellular digestion.
Extrorse Turned or facing outwards.
Toward the outside.
See
introrse.
Eye Spots
Structures present in some freshwater and marine nematodes which consist of a
lenticular
cuticular
body situated on a pigment cup.
F1
The first-generation offspring resulting from a given mating.
F2 the second generation, etc.
Facultative Aerobic Capable of living without the
presence of atmospheric oxygen, though capable of utilizing it when available.
Facultative Anaerobic
Normally living in the presence of atmospheric oxygen, but capable of becoming
anaerobic. See aerobic, anaerobic, facultative aerobic,
obligatory
aerobic, obligatory anaerobic.
Facultative Parasite Organisms ordinarily saprophytic
or saprozoic which may
become parasitic under certain conditions.
See obligate parasite, facultative saprophyte.
Facultative Saprophyte
Organisms ordinarily parasitic which may subsist as saprophytes during part of
their life cycle but do not complete their cycle away from a host. See
facultative parasite, obligate parasite,
obligate
saprophyte.
Fahrenholz's rule (1913) .When
host-parasite cospeciation has occurred, the phylogenies of the host and
parasite come to mirror each other. However, often phylogenies are
altered by host switching, extinction, independent speciation, and other
ecological events so cospeciestion may be difficult to detect. See
cospeciation, phylogeny.
Falcate
Curved like a sickle.
Falciform
Having the shape of a scythe or sickle.
Fallow
Cropland left idle in order to restore productivity, mainly through accumulation
of water, nutrients, attrition of pathogens; probably a combination of these.
Family
In the systematic arrangement of organisms into groups or categories denoting
natural relationships a category ranking above a genus and below an order.
See classification.
Fascicle
A bundle. A cluster.
Fat Body
A trophosome.
Faulted The interruption then
continuance of a line parallel
to the original but on a different plane.
Fauna
Animals or animal life. See flora,
biota.
Faunal Analysis Assessment of the
relative proportions of nematodes of different feeding habits and life
history characteristics to provide inference of the state of the soil
ecosystem and its potential for providing Ecosystem Services.
Fecundation Fertilization, as of eggs by spermatozoa.
Fecundity The abundance of offspring
produced by a female or the rate of offspring
production.
Feeding The intake of substances essential to growth,
sustenance and maintenance of an organism.
See
bacteriophagous,
bacterivore, biophagous,
carnivorous,
coprophagous,
cycophagous,
detritophagous,
fungivore,
fungivorous,
herbivorous,
lancinate,
microbivorous,
microphagus,
monophagous,
mycohelminths,
mycophagous.
nematophagous,
oligophagous,
ominivorous,
parenteral
feeding,
phyllophagous,
phytophagous,
polyphagia,
polyphagous,
polyphagy,
predaceous, predator,
rapacious,
rypophagous,
saprobiont,
saprophage,
saprophagous,
saprophyte,
saprozoic,
saprozoite,
sarcophagous,
scavenger, voracious.
Female Gangs
The female genitalia.
Female Genital Aperture The vulva.
Female Intersex
An individual which begins development as a female but finishes development as a
male. See intersex, male intersex.
Fenestra (pl.
Fenestrae) A window.
A transparent spot.
In the genus Heterodera
a thin walled transparent region
of the vulval
cone which may breakdown to form the hatching pore.
The thin- walled region about the anus in some
Heterodera.
See
fenestrate, semifenestrate,
bifenestrate,
ambifenestrate,
circumfenestrate,
vulval
fenestra,
anal fenestra.
Also, and opening through which a nerve passes.
See Figure 30,
Figure 31,
Figure 32,
Figure 34.
Fenestration
The process of forming the hatching pore
by the breakdown of the thin areas of cuticle of the anal or
vulval
cone.
Ferment Saliva.
Fertilization Membrane The lipoid
membrane.
Fiber Cells
Modifications of the hypodermis which contributes to the formation of the lips,
two in the dorsal lips and one in the lateral and ventral lips.
Fiber Layers
Three cuticular
strata of dense connective tissue which is oblique,
ribbon-ike,
possibly spiral and delimited by the boundary layer and the basal lamella.
See
cuticular
layering.
Fibril (pl.
Fibrillae)
The
fibers which constitute the actual contractile substance of the muscle cell.
Fibril Cells
Three coelomocytic
cells which lie adjacent to the esophagus and opposite the three esophageal
radii. See coelomocytes,
binding cells.
Fibrillae
Thread or fiber-like
supporting structures of the hypodermis.
Fibrillar
Layer
The cuticular
stratum consisting of a condensation of spongy matrix forming a closely woven
network between the internal cortical layer and the matrix layer. See
cuticular
layering.
Fibrillar
Terminals
The nerve endings of the amphidial
nerve coiled within the amphidial
pouch. End organs.
Fibroplasm
That portion of the muscle cell differentiated into muscle fibers. See
sarcoplasm.
See
Figure 8,
Figure
9.
Fibrous Root System
Adventitious roots which arise from the base of the stem, bulb or corm. See
Lap root system.
Field Capacity
The amount of moisture remaining in a soil after the free water has been allowed
to drain away into drier soil material beneath; usually expressed as a
percentage of the oven dried weight of soil. It is the highest amount of
moisture that the soil will hold under conditions of free drainage after excess
water has drained away following rain or irrigation.
Filament
A slender, thread-like object, process or appendage.
Filaria(ae) See Filarial Nematode
Filarial Nematode or Filarial Worm Any of a group of animal-parasitic nematodes that require two hosts to complete the life cycle, an intermediate host (often an arthropd) and a primary host (usually a vertebrate). The juvenile stages occur in the intermediate host and the reproductive adult in the definitive (primary) host. Transmission occurs by the intermediate host biting the primary host or the intermediate host being eaten by the primary host. Inflammation of the definitive host tissues is called Filariasis. See Filariasis
Filarial Worm Systematics Nematodes of the families Filariidae, Onchocercidae and other taxa of similar biology, Historically, filariae referred to genera of nematodes in the Filariidae. However, when the family Onchocercidae was established, many of the genera previously considered to be filarial worms in the Filariidae were transferred to Onchocercidae.and other taxa of similar biology.
Filariasis A disease of a primary host cause by filarial nematodes. Eight species of filarial nematodes have humans as the definitive host. They can be divided into three groups:
a) Lymphatic filariasis is caused by nematodes occupying and disrupting the lymphatic system, often resulting in significant swelling of tissues and elephantiasis. Nematode species in this group include Wuchereria bancrofti, Brugia malayi, and Brugia timori.
b) Subcutaneous filariasis is caused by nematodes occupying the subcuatneous layers of the skin, including the eye. Species in this group include Loa loa and Onchocerca volvulus which causes river blindness.
c) Serous cavity filariasis is caused by nematodes occupying mesothelial tissues in the body cavity of the host. They include Mansonella perstans and Mansonella ozzardi in the host abdomen and Dirofilaria immitis in the heart of dogs.
Filiation Descent from a parent.
Lineage.
Filiform
Having the shape of a thread or filament.
Filling Cells
The cells of the lip pulp other than the
clavate
cells, fiber cells or arcade cells.
Fimbriate
Fringed.
Final Host The definitive host.
Finger-like
See digitate.
First Bulb The metacorpus.
Fissiparous The production of
individuals by fission. See reproduction.
Fissura Cephalica
Head cleft.
Fissure A cleft or groove separating
adjacent tissues, parts or organs.
Fitness The level of adaptation of
an individual or species to existing environmental conditions resulting in
survival and reproductive success
Fix To harden
and preserve relaxed specimens especially for permanent mounting and microscopic
study.
Fixative
Generally a mixture of chemicals which harden and preserve the bodies of relaxed
specimen s.
Fixed Athrocytes
Stationary coelomocytes
capable of absorbing foreign material from the body fluids and storing it in
crystalline form. See coelomocyte.
Flaccid Limp.
Feeble.
Limber.
Flabellum. Fan- or feather-shaped dorsal or ventral extensions of the
cuticle.
Flagellum
In differential staining of mermithid
larvae bodies with carmalum,
the posterior region stains very light and is termed "flagellum."
Flange
A rib, rim or expansion developed for strength, guiding or attachment to another
part or organ. See
Figure 4.
Flap Apparatus
The valvular
apparatus.
Flask-shaped
See ampullate,
ampulliform,
lageniform.
Flavate
Bodies
Where present, four elongate, yellowish,
gland-like
structures situated submedianly
near the base of the stylet.
Flesh Consuming
See biophagous,
carnivorous, feeding.
Flooding
A control measure against plant parasitic nematodes where soil is kept
saturated or submerged.
Flora
Plants or plant life. See fauna, biota.
Flush
The development of a generation of nematodes.
Focus (pl. Foci) A localized region of disease or the principal site of a general disease.
Foregut The esophageal region of the alimentary tract. See midgut, hindgut.
Forked See furcate, trichotomous, tricuspid, tricuspidate, tridentate, trifid, trifurcate.
Fornent In an opposite position. Facing. See apposition, juxtaposition.
Fossa A ditch-like depression.
Fossorial Equipped for, or capable of digging.
Framework A cephalic structure which provides rigidity to the head. It is subcuticular and axially forms a stylet guide in stylet-bearing forms. See calvarium.
Fovea A pit or depression, a small fossa.
Frass Solid excrement of larval insects.
Free-living Living independently of any host organism. A nonparasite. See parasite.
French Bud A disease of strawberry incited by Aphelenchoides fragariae. See dwarf.
Frenching A disease of strawberry incited by Aphelenchoides fragariae. See dwarf.
Fringe An edging of processes extending beyond the margin and are usually of equal length. See fimbriate.
Frontal Disc The labial disc.
Frustule The hard and porous external silicaceous layer of diatoms; sometimes seen in intestines of free-living nematodes and considered an indicator of feeding sources.
Fumigant Nematicide A nematicidal chemical with high volatility that moves through the soil primarily in the gaseous phase.
Functional Group A group of species that contribute to the same ecosystem function.
Functional Guild Subsets of a Functional Group with similar general biology, structure or behavioral adaptations. See Functional Group; Trophic Guild..
Fungivorous Feeding on fungus mycelium. See feeding.
Fungivores Organisms that feed on fungi.
Fungus (pl. Fungi) A low form of plant life which lacking chlorophyll and being incapable of manufacturing its own food, lives off dead or living plant or animal matter. The body of a fungus consists of delicate threads (hyphae) which in mass form branched systems called mycelia.
Funnel-shaped See infundibuliform.
Funnel Technique See Baermann funnel technique.
Furca The branched distal part of a probola.
Furcate Forked. Having two divergent branches with a common base.
Fusiform Spindle-shaped.
Tapering toward each end.
Gall A pronounced localized swelling. An outgrowth of
unorganized cells generally more or less spherical or
fusiform.
Gallery
A passage or tunnel made by an animal.
Galvanotaxis A tactic response in which an electric
potential is the stimulus.
See Taxis.
Gamete
A mature reproductive cell. See spermatozoon, ovum.
Gametogenesis
The development or formation of reproductive cells.
Gamogonic
Pertaining to sexual reproduction.
Ganglion
(pl. Ganglia) A well defined concentration of nerve cell bodies forming a
nerve center.
Gas Application The treatment of soil or other
material with a nematicide
in a vapor phase.
See broadcast application, drench application, row application.
Gaseous Aeriform.
Gastrula
The early embryo, consisting of an open mouthed sac-like body with a wall
of two layers of cells, an outer
epiblast
and an inner hypoblast. The opening is called
the blastopore
and the central cavity the archenteron. See blastula.
Gavage
Introducing contents into the stomach by means of a tube.
Gene The basic unit of heredity in a
living organism. A segment of genomic information encoded by DNA that specifies
a trait. See DNA..
Gene-for-Gene A hypothesis proposed by Flor that for each gene conditioning a reaction in a host, there is a corresponding gene in the pathogen that codes for pathogenicity. See gene.
Generalist Predators Nematodes that feed on other living organisms but not necessarily restricted to a single type iof prey. See specialist predators.
Generation A single set of progeny in the succession of natural descent. The period of time in which one set of progeny follows another. See life cycle..
Geniculate
Bent to an obtuse
angle.
Genital Aperture
The vulva in females, The
anus leading
to
a cloaca
in males.
Genital Armature
All the apparatus involved in copulation.
Genital Cone
A posterior projection of the region around the
cloacal
orifice. The
cloacal prominence.
Genital Organs The reproductive organs.
See ovary, testis.
Genital Papillae
(GP)
Tactile papillae or setae in the anal region of the male and may be
preanal,
postanal
or caudal in position. See
pedunculated
papillae, rosettes, plectanes,
copulatory
warts, preanal
sucker.
Genital Primordium
The initial cells leading to the development of the reproductive system.
Genital Setae
See genital papillae.
Genital Tract
The gonads.
Genital Tubes
The gonads.
Genitalia
The organs of generation. In the male these consist of the testis, seminal
glands with their ducts, gubernaculum
and spicule.
In the female the vulva, vagina, ovary, oviduct, seminal receptacle and uterus.
Genoholotype
A genotype specifically named as generic type by the author. See type.
Genolectotype
The type of a genus selected from a series of species placed in the genus after
the description. See type.
Genome The complete set of genes or genetic material in a cell.
Genomics Study of the structure, function, evolution and mapping of genomes.
Genosyntype
One of a series of species upon which a genus is based with no one species
having been established as type. See type.
Genotype
The species which is designated as the type species of a genus. See type.
Genotype
The total genetic makeup of an individual or group. See phenotype.
Genus
(pl. Genera) In
the systematic arrangement of organisms into groups or categories denoting
natural relationships a category ranking above a species and below a family. In
binominal nomenclature the first word of the scientific name of a species is the
generic name and is capitalized. The second term is the trivial name and is not
capitalized. See classification.
Geographical Distribution The inhabited range of a
species.
Geotaxis
A tactic response in which gravitational attraction is the stimulating factor.
See taxis, tropism.
Geotropism
A tropic response in which gravitational
attraction is the orienting factor. See tropism, taxis.
Germarium The germinal zone.
Germ Layers The layers of cells that are distinguishable in the embryo immediately after gastrulation. In most animals, the layers give rise to similar tissues and organs. Diploblastic animals, such as Coelenterata, have two layers, ectoderm and endoderm. The ectoderm gives rise to external structures and the endoderm to internal structures such as intestine and reproductive organs. Triploblastic animals have a third layer, mesoderm, which gives rise to muscle and skeletal structures and which surrounds the body cavity.
Germinal Zone
That part the ovary where the oogonia
divide. See growth zone.
Giant Cells
A structure formed most commonly in root tissue by the coalescing of several
cells through dissolution of common walls under stimulation of salivary
secretion by gall-forming nematodes and some other kinds.
Lysigenoma.
See hypertrophy, hyperplasia, nurse
cell.
Gland Nuclei
and Orifices See Esophogeal Gland Nuclei and Orifices.
Gland-like Adeniform.
Glandular Esophagus
A ventricular esophagus.
Gliding Ring The guiding ring of the
stylet.
See guiding ring of stylet,
Figure 2.
Globate Spherical.
Globular
Globe-shaped. Spherical.
Glottoid
Apparatus
The metastom
of Rhabditids
and Diplogasterids
formed of one dorsal and two subventral
metarhabdions.
See isoglottid,
isomorphic. Figure 40
Glottoid Part Distinct regions of the
stoma consisting of one dorsal and two subventral pieces that may be of
different shape (anisomorphic) or in different positions (anisotopic). May
bear denticles or teeth.
Glottoid
Teeth
Metarhabdion
projections of the glottoid
apparatus.
Glucoprotein
A segregate
of the cuticle (a mucoid).
Glucosamine The chief constituent of chitin.
Glucose
A simple 6-carbon sugar.
Glycogen Animal starch.
A soluble polysaccharide made up of numerous glucose molecules.
The form in which carbohydrates are stored in the animal.
Helminth
glycogen is a mixture
of compounds varying considerably in molecular weight.
Gnathi Jaws.
Gnotobiotic Pertaining to the rearing of an organism
with no other or only known species of associate organisms.
See Agnotobiotic,
axenic,
xenic,
synxenic,
monoxenic,
dixenic,
trixenic,
polyxenic.
Gonad
A primary sex gland. An ovary or testis.
Gonochoristic
Sexually reproducing
species in which there are at least two distinct sexes. The sex of an individual
is genetically determined and does not change throughout its lifetime.
Gonochorism
Sexual reproduction involving two distinct sexes.
Gonoduct
A reproductive tube.
A
gonad.
Gonopore
The opening to the exterior of the gonads; the vulva in the female and the anus
in the male.
GP See genital papillae
Gradual Metamorphosis Incomplete metamorphosis.
Granek's Ratio In Heteroderidae, the
distance from the edge of the fenesta to the anus divided by thelength of
the fenestra.
Grape Cluster-like
See aciniform,
botryoid.
Gravid
Bearing an egg or eggs.
Gravity Flow System
A method of applying liquid nematicides
to soil utilizing liquid head, liquid viscosity, tubing diameter and tractor
speed for regulating the rate of application.
Grinder
Cuticular Plates in the posterior
bulb of the esophagus of many bacterial-feeding nematodes. Have the
function of crushing bacteria prior to digestion in the intestine. See
chewing plates, valve plates,
Figure 40
Grouped
See agminate, aggregated.
Growth Zone
That part of the ovary where the oogonia
develop. See germinal zone.
Guard Process One or two cuticular
projections at the base of a primary axil. See primary axil,
Figure 36.
Gubernacular
Muscles
Specialized muscles for the functioning of the
gubernaculum.
See retractor gubernaculi,
protractor gubernaculi,
seductor
gubernaculi.
Gubernaculum
In male nematodes a grooved cuticularized
structure, sometimes paired, which guides the
spicule
and is formed by sclerotization
of the
dorsal wall of the spicular
pouch. See cuff, crura. See
Figure 5,
Figure 14,
Figure 16,
Figure 41.
Guide Collar
The guiding ring of the stylet.
Guide Ring
The guiding ring of the stylet.
Guiding Ring of Stylet
The anterior end
of a guiding sheath of the stylet
cuticularized
or muscular thus appearing
to be more dense than surrounding tissue. See guiding tube of
stylet.
See Figure 2.
Guiding Tube of Stylet
A sheath about the stylet
extending from the "guiding ring" to the
stylet
base. See Figure 4,
Figure 6.
Guild A group of
species with similar behavior, life history
characteristics or ecosystem function. See functional guild,
structural guild.
Gut
The intestine.
Guttate Drop-like.
Guttiform
Having the shape of a drop. Drop-like in form.
Gynandromorph
An individual in which the secondary male and female characters are present in
the same individual but different parts of the body, sometimes an hermaphrodite
but not necessarily so, See intersex, reproduction.
Gyne An unmated adult female bumblebee that returns to the overwinter burrow and becomes infected by parasitic nematodes such as Sphaerularia bombi, or disperses juveniles of the nematode.
Gynodioecious Descriptive of a population expressing the characteristics of gynodioecy.
Gynodioecy The condition in which a population comprises both females and hermaphrodites.
Gynogenesis The process by which progeny are developed solely from the maternal genome; i.e. sperm DNA is not utilized. See Parthenogenesis.
Gynotype
A
female type.
See
type.
Habitat The natural environment
of an organism, specifically, the locale in which it grows and lives.
Haemolymph The watery
lymph-like nutritive fluid of the nematode
pseudocoel.
Hairy See
piliferous, trichoid.
Hairy Root A condition of excessive root branching
induced by nematode feeding.
Half Turned See hemitrope.
Halophilous,
Halophilic
Living in a salty environment.
Hamabiosis A form of
symbiosis in which two species live in association without obvious motive
or advantage to either symbiont.
Hamate
Having a hook or hook-shaped. See
adunc.
Hand-shaped
See palmate.
Haploid Single in appearance or arrangement.
Having the basic (n) number of chromosomes for
the species.
See diploid.
Haplotype
A set of alleles (DNA variants) along a single chromosome that tend to be
inherited together.
Because of their proximituy on the chromosome, recombination amongst these
alleles is rare. See genotype, allele.
Hard Cuticle The material that builds up the jaws
teeth, cuticular lining
of the oral cavity and the male genital armature.
It has consistency
of chitin. See soft cuticle.
Hatching The breaking of the egg shell by a larva
during the process of emergence.
Eclosion.
See spontaneous hatching.
Hatching Factor
An external hatching stimulus which acts on eggs.
See root diffusate,
leachate.
Hatching Pore The
fenestra.
Hatch Plant
A host plant capable of inducing larval emergence from eggs.
Haustrulum Cuticularized chamber(s) posterior to
metacorpus valve.grinder/pump.
See
Figure 15,
Figure 40.
Head Bristles
The cephalic crown of papillae or setae.
Head Bulb
Specialized cuticular
inflations which form a band-likc
structure immediately posterior to the lips. See ballonets.
Head Cap
A distinctively set off head region.
Head Cleft
A pouch-like
cephalic sensory organ, lateral in position, which possesses, in comparison with
the amphids,
a simpler innervation.
Also termed cephalic organ,
organe
cephalique,
fissura
cephalica.
Head Offset
Head region delimited by a depression or a constriction.
Head Shields
Cuticular
collar extensions that arch over the lips, considered
interlabia
by some authors.
Heautotype
A specimen indentified by the author as an illustration of his species and
compared with the type or cotype.
Autotype.
See type.
Hectare A. unit of land area equivalent to 2.471 acres.
Helix
Having a spiral form.
Helmet
A thickening in the labial region set off by a groove and denoted by a lack of
ornamentation of the anterior cuticle. See cane.
Helminth
A worm.
Helminthiasis
A
disease incited by worms in or on a host.
Helminthic Relating to, or belonging to, worms.
Helminthology The branch of zoology dealing with worms, especially parasitic worms.
Hemi-rosette An optical-dense semicircular structure with corrugated arch edging connecting the uteri of some frehwater free-living nematodes.
Hemispheroid Having the shape of half a globe or sphere. Semiglobose.
Hemitrope Half turned around. Half inverted.
Hemizonid A nerve
commissure of a highly
refractive nature, generally biconvex in longitudinal section and which extends
ventrally from lateral cord to lateral cord. See
cephalids,
hemizonion,
caudalid,
parahemiizonid.
See
Figure 1,
Figure 4.
Hemizonion A small nerve
commissure with many characteristics of the
hemizonid
and apparently always shortly posterior to the hemizonid. See
cephalids,
hemizonid,
caudalid,
hemi.
See
Figure 1,
Figure 4.
Herbivores Organisms that derive their sustenance
entirely from vegetable matter.
See feeding.
Herbivorous
Feeding on vegetable matter. See feeding.
Heredity Transmission of genetic characters of
parents to their progeny.
Hermaphrodite
An individual with both functional male and female reproductive organs.
See protandrous
hermaphroditism,
digonic
hermaphrodite, syngonic
hermaphrodite, intersex.
gyandromorph,
androgynous, reproduction.
Heterogeneous
Differing in kind, qualities
or nature. See homogeneous.
Heterogenetic Development where the larvae do not
resemble the parents.
See monogenetic reproduction.
Heterogonic
Cycle
A situation where eggs of parasitic parents develop into free-living males and
females, their progeny then proceed to the parasitic phase.
Indirect cycle.
See homogonic
cycle.
Heterogony Alternation of two sexual generations or
of a sexual and a hermaphroditic generation.
See reproduction.
Heterology
The lack of similarity between structures from being composed of different
components or of a different derivation, See
anology,
homology.
Heterolysis Destruction of a cell by an external
agent, especially, by lysins
or enzymes from an outside source.
See autolysis.
Heteromorphic
Having different forms at different life stages. See dimorphic,
monomorphic.
polymorphic.
Heteroploid
Having a greater or smaller chromosome number than the diploid number but not a
simple multiple of the haploid chromosome number. See
monoploid,
aneupolid,
euploid.
hyperploid,
polyploid.
Heterotroph An organis that depends on another organism, living or dead, as a source of food and energy, See Autotroph
Heteroxenous Development Development of a parasite that requires
two or more host species. See diheteroxenous, dixenous,
triheteroxenous, trixenous.
Heteroxeny See Hetoxenous
Development.
Hexamerous
Having six radially-arranged
parts or structures.
Hexebesen
A witches broom condition on a plant.
Hiatus
A natural opening in the egg shell. See plug. May also refer to a space
or gap in a sequential arrangement of structures such as supplements.
Hibernation
The anabiotic
state.
See anabiosis.
Hill Application
Spot application of a nematicide.
Hindgut The rectum.
See foregut,
midgut.
Hispid Rough with minute spines.
Hispidulous Minutely hispid.
Historopic Attracted towards tissues.
Holapopmorphy
Holarctic
Realm A faunal area comprising Europe
North Africa, to the Sahara desert, Asia to the Himalaya Mountains and the North
American continent down to
Holidic
Pertaining to a medium whose intended constituents, other than purified inert
materials, have exactly known chemical structures before compounding. See
meridic,
oligidic.
Hologonia A gonad where proliferation of primordial
germ cells extend along its entire length.
Hologonic
Gonads
See hologonia.
Holomyrian A situation where the longitudinal muscle
cells are indistinguishable as individual cells especially as viewed in
transverse section.
See meromyarian,
polymarian.
Holotype
The individual specimen selected as type of a species by the author. See
type.
Homogeneous Similar in kind, qualities or nature.
See heterogeneous.
Homogenous Layer
The matrix layer of the cuticle.
Homogonic Cycle
A
situation where eggs of parasitic
parents hatch into free-living larvae which develop directly into parasitic
forms. Direct cycle.
See heterogonic
cycle.
Homologue A part or organ of the same relative
structure, position or
origin as another.
The same in different individuals varying in form and function. See analogue.
Homologous
Similarity of structure, but independent of function, See analogous.
Homology
Structure of fundamental similarity, but independent in function, derived from
descendence
through some common ancestral form. See
heterology.
Homonym
A generic or specific name already occupied
and
therefore rejected due to the law of priority which requires the use of the
earliest published name. Two or more entities having the
same
name.
Homotype
A specimen compared with the type and determined to be
conspecific
with the type. See type.
Honeycombed
See alveolate.
Hook-like
See adunc,
hamate,
unciform,
uncinate.
Horn-shaped See bicorn, corniform.
Horizontal Gene Transfer
(HGT) The transfer of genetic material between organisms in a
manner other than sexual or asexual reproduction, e.g. by transformation or
viral infection. See vetrical gene transfer.
Horizontal Resistance Resistance to races or biotypes of
the nematode species is uniform, not race specific - reduces selection pressure.
Usually controlled by several genes. See
resistance.
Host
The organism which is invaded or parasitized by a disease-producing agent and
from which the parasite obtains its
sustenance.
See host range, suscept.
Host List
The range of organisms infected by a specific parasite. See host range.
Host Plant
The plant which affords sustenance to a nematode parasite and allows
reproduction.
Host Preference
The selection of a host most suitable
for the survival of the parasite.
Host Race
Nematodes of the same
species differing only in their preference of host plants. See
race, physiologic race.
Host Selection The food preferences of parasitic nematodes.
Hot water Treatment The steeping of bulbs, seeds and
other plant parts in a water bath at a temperature lethal to the infecting
nematodes and leaving the
plant material undamaged.
Humidity The weight of water vapor in a given quantity of air, compared
with the total weight of water vapor which the air is capable of holding at a
given temperature.
Humus The well decomposed organic matter in mineral soils.
Hyaline Clear.
Transparent. Without color.
Glassy.
Hydrogen-ion Concentration A measure of the acidity
of a chemical in solution. The greater the
concentration of hydrogen ions, the more acid the substrate. The
hydrogen-ion concentration is expressed in terms of the pH of the substrate.
See pH.
Hydrolysis A chemical decomposition process of a compound which involves
the addition of the elements of water.
Hydrotaxis A taxis in which a moisture
gradient is the response initiating stimulus.
Hygroscopic Readily absorbing and retaining moisture.
Hyperparasitism A
situation where parasites in turn are
parasitized by other organisms.
Hyperplasia The abnormal increase in the number of cells of a tissue.
See hypertrophy.
Hyperploid Having a chromosome number
slightly greater than an exact multiple of the haploid number. See
monoploid, euploid,
aneuploid, heteroploid,
hyperploid, polyploid.
Hypersensitive A violent reaction to parasitic attack resulting in sudden
death of invaded tissues providing a barrier against further invasion.
Hypertonic A solution having an osmotic pressure higher than an isotonic
fluid such that it gains water by osmosis across a membrane. See
isotonic, hypotonic.
Hypertrophy The abnormal enlargement of cells
generally by dissolution of common cell walls. See hyperplasia.
Hypha (pl. Hyphae)
One of the thread-like strands, or filaments, that
constitute the body or mycelium of a fungus. It may
be divided into cells by cross walls, a
septate condition, or be one
elongated cell with several nuclei, a nonseptate
or coenocytic condition. The
hypha may be coarse or fine, aerial or submerged,
stiff or flexible and exhibit different types of branclung.
Some hyphae are specialized for producing spores or
for penetrating host tissue.
Hypoblast The inner layer of the
blastoderm. See epiblast.
Hypodermis A thin cell layer beneath the cuticle with longitudinal
thickenings protruding between the longitudinal muscles to form the cords which
contain the nuclei of the hypodermal cells, See
lateral cord, ventral cord, dorsal cord. See
Figure 21.
Hypogaeic Subterranean.
Living underground. See arenicolous,
aquatic, edaphic, marine,
rheophile, terrestrial,
terricolous, xerophilous.
Hypothesis (pl. Hypotheses)
A tentative explanation of a phenomenon. See postulate, theory.
Hypotonic A solution having an osmotic pressure lower than an isotonic
fluid such that it loses water by osmosis across a membrane. See
isotonic, hypertonic.
Hypotygma Papilla-like processes on cloacal aperture
of male.
Hypotype A specimen, other than the type, upon which a subsequent or emended description or figure is based. Apotype. Plesiotype. See type.
Ideotype
A specimen named after
comparison with the type, to be distinguished from a
topotype. See type.
Imbricate Arranged or appearing lapped over one another like shingles on
a roof.
Imbrication An overlapping of the edges as of tiles
or shingles.
Immature Not yet at the state of full sexual
development.
Immobile Larva The development of the male of
cyst-forming nematodes within the cuticle of the third stage larva.
Immunity The ability of an organism to remain free from a disease or of
parasitism by
virtue of inherent properties of that organism. An immune organism is exempt
from the-particular disease. See tolerant, resistant.
Impermeable Not permitting passage. Impervious.
Impregnation The act of rendering pregnant.
Fecundation.
Incisures See involutions.
Incompatible Host-Parasite Relationship
Incomplete Metamorphosis A growth phenomenon where young through
successive stages, or instars acquire adult
characteristics which become functional at maturity.
See complete metamorphosis.
Increase Factors The several formulae used to calculate the gain in
population of cyst-forming nematodes as follows:
Increase factor X1
= (total cysts obtained at season's end)/(original number of cysts)
Increase factor X2
= (number new cysts produce at
season's end)/(original number of cysts)
Increase factor X3 =
(total eggs obtained at season's end)/(original number of eggs)
Increase factor X4
= (number new eggs produced at
season's end)/(original number of eggs)
Incubation
The period of time and conditions of
environment between inoculation of an organism by a disease-producing agent and
the appearance of symptoms.
Indentate Having an irregular margin. See
serrate.
Indicator Plant A suitable suscept plant used
to signify the survival or reproduction of plant-parasitic
nematodes after some treatment or
condition of population stress.
Indigenous Living in its natural or
original locality. Native. See endemic.
Indirect Cycle Eggs of parasitic parents develop into free-living males
and females, the offspring then proceed to the parasitic phase.
Heterogonic cycle. See
homogonic cycle.
Indirect Development Complete metamorphosis.
Indomalayan Realm The biogeographic
region that includes the Indian subcontinent and southeast Asia.
See Holarctic Realm. Neotropical Realm, Afrotropical Realm,
Australasiian Realm.
Infect To invade and establish a parasitic relationship within the host
proper. See infest.
Infection Incidence The population density of
attacking parasitic nematodes.
Infectious Larvae Infective larvae.
Infective Having the qualities necessary to enter a host and
produce a disease condition.
Infective Larvae Nematode larva at a stage of
development capable of penetrating and infecting a host.
Infective Juveniles Infective larvae.
Infective Stage The period of development in the life
cycle of a parasitic nematode in which it possesses the qualities enabling
infection of a host.
Infest To attack externally. To contain the parasites, said of nonliving
material. See infect.
Inflated Annules
Enlarged annules often
with a lumen or other
modification of
an
intra-annule
cavity.
Inflation of the Cuticle A blister-like
swelling of the cuticle.
Inflect To curve or bend inwards or towards the axis. See
infiexed.
Inflexed Curved, bent or directed abruptly
inward, downward or toward the body axis. See inflect.
Infraspecific Included within a species.
See con- specific.
Infundibuliform Funnel-shaped.
Ingest To take substances, especially food, into the body.
Inhalation LC50 The concentration of a chemical at which
50% of the target organisms are killed when the chemical is inhaled; for example, 10 mg of chemical per
liter of air. See lethal concentration.
Injury Damage of relatively short duration to an organism. See
disease.
Inlet Valve The esophageal lumen just anterior to the
valvular apparatus and opening into the
haustrulum. -
Inner Body The inner mass
Inner Circlet The crown of inner labial papillae.
The internal circlet. See outer circlet:
See
Figure 2,
Figure 22,
Figure 23..
Inner Cuticular Layer This layer corresponds
to the fiber layers of the cuticle. See
Figure 21.
Inner Labial Situated on that part of the lips located closest to the
longitudinal axis. See inter labial, outer labial.
Inner Labial Bristles Inner labial papillae which have been altered to
bristle-like structures.
Inner Labial Papillae Sensory papillae situated toward the apex of the
lip segment forming a circlet of six in primitive
forms. See outer labial papillae. See
Figure 22,
Figure 23..
Inner Leaf Crown An amplification of the
corona radiata by the formation of a second more
posterior crown of lobes. See
Figure 12.
Inner Mass A darkly staining structure slightly
post-equatorial in microfilariae.
Inner Membrane The lipoid membrane.
Innervation The nerve distribution to or in a
part or organ.
Inoculate To cause an infectious agent (the maculum)
to come in contact with a host.
Inoculant Inoculum.
Inoculation The communication of an infective agent to the host to cause
a disease.
Inoculum The infectious agent used in
inciting a disease.
Inorganic Substances
occurring as minerals in nature or obtainable from
them by chemical means. All matter except the compounds of carbon, but
including carbonates, Inanimate. See organic,
Inseminate To introduce spermatozoa into the vagina of female nematodes.
Insemination The introduction of semen into the
female reproductive tract. See copulation.
Instar The nematode larval condition
of growth assumed between successive molts. See molt,
ecdysis, larval stages, stadium.
Integument Cuticle.
Covering. Investment.
Skin.
Intercallary Additional.
Interpolated. Inserted between.
Intercordal Areas The
nonthickened regions of hypodermis devoid of nuclei
lying between the cords. See cords.
See
Figure 21.
Interface
The common surfaces of two bodies.
Interior Mass Inner mass.
Interkinesis The interval between mitoses of a
nucleus.
Interlabia Small lobes situated
between the lips.
Interlabial Situated between the lips. See
inner labial.
Interlabial Clefts The space or
fissure separating the lips.
Intermediate Host The host in which the asexual stages of a parasitic
life cycle take place.
Intermediate Striae The lesser lines situated
between the major configuration lines of a
perineal pattern. See partial
striae, lighter striae,
broken striae.
Internal Circlet The crown of inner labial papillae.
The inner circlet.
Internal Cortical Layer The cuticular stratum
bounded by the external cortical layer on the outer most side and the
fibrillar layer on the inner side. See
cuticular layering.
Internal Egg Mass Eggs of Meloidogyne
spp. deposited in matrix within the gall tissue. See egg mass,
external egg mass.
Internal Parasite
Endoparasite.
Interphasmidal Line An imaginary line
connecting the phasmids in a
Meloidogyne perineal pattern.
See
Figure 28,
Figure
29.
Intersex An individual which exhibits a blending
of male and female
characters and which function as one or the other or
neither sex, but never as
both. See gyandromorph, male intersex,
female intersex.
Interstitial The space between grains of sand on a beach, river
bank or estuary.
Interstrial Region The area between
two striae.
Intestinal Caecum A blind
diverticulum arising at the anterior of the
intestine and extending anteriorly next to the
esophagus.
Intestinal Tract The alimentary canal. See
Gut. See
Figure 3.
Intestine A simple tube, composed of a single
layer of epithelial cells in which digestion of food takes place.
Gut. See
Figure 1,
Figure 18.
Intestino-Rectal Sphincter The valve of intestinal
tissue separating the intestine from the rectum or
cloaca.
Intestino-Rectal Valve The
intestino-rectal sphincter.
Intima An internal lining.
Intima of the Esophagus A
cuticularized tube of
triradiate form circumscribing the lumen of the esophagus.
Intorted Turned or twisted
inward. See
extorted.,
Intracellular Occurring or situated within a cell.
Intracellular Digestion The digestion of food
particles within the cell. See extra-oral
digestion, predigestion, extracellular digestion.
Intrados The interior curve of an arch. See
extrados.
Intraoral Within the mouth.
Intrauterine Within the uterus.
Intrauterine Generations The development of mature males and females
within the uterus of the mother; then yet another generation may develop within
the progeny.
Intravial Stain See intra
vitam.
Introduced Species See
adventive.
Introrse Facing or directed inward,
See extrorse.
Invalivate To mix with saliva.
Invasion Growth or movement of an infectious agent into a host with its
subsequent establishment as a disease. See attack, infective.
Invasive Larvae Infective larvae.
Ivermectin Anthelminthic and insecticide chemically derived
from avermectins. See avermectin, abermectin
Invertebrate Without a backbone or vertebral column.
Involutions The longitudinal
cuticular clefts which
divide the lateral fields. Incisures. See
Figure 17,
Figure 19,
Figure 21.
Ion An atom or molecule bearing an electrical charge.
See anion, cation.
Isoglottid Having the
metarhabdions of the glottoid apparatus at
the same level, See anisoglottid.
Isolation Tissue The pseudocoelomic membranes
and mesenteries.
Isomorphic Of identical or like form especially pertaining to the
metarhabdions of the glottoid
apparatus See anisomorphic.
Isotonic Having equal osmotic pressures. See hypotonic,
hypertonic.
Isthmus The segment of musculature between the medium bulb and basal bulb
of the esophagus. See corpus, basal bulb.
See
Figure 1
Iteroparity A species is considered iteroparous if it is characterized by multiple reproductive cycles over the course of its lifetime. See Semelparity.
J2 an abbreviation for second-stage juvenile; the infective stage of many plant-parasitic nematodes.
J3 an abbreviation for third-stage juvenile
J4 an abbreviation for fourth-stage juvenile
Jaws A
cuticular framework around the mouth which functions
in grasping and holding; fundamentally 3 partite. Teeth in
the broad sense.
Juvenile A nematode in a developmental stage which does not yet have
functional gonads. Any immature nematode.
Juvenile Female A fourth-stage female in which the vagina and uterus are
functional but the ovaries have yet to mature. See
koriogamy.
Juxtaposition Situated adjacent to another. The act of being placed side
by side. Apposition. See fornent.
Kairomone A semiochemical, emitted by an organism, which mediates an interactions between species that benefits individuals of a species receiving the signal and harms individuals emitting the signal. See semiochemical, allomone, synomone, pheromone.
Karyokinesis
Mitosis.
Karyoplasm The protoplasm of the nucleus.
Nucleoplasm.
Keel-like See carina.
Keratin A segregate form of the cuticle corresponding to the external
cortical layer. See cuticular layering.
Kidney-shaped See
reniform.
Kinesis Movement induced by a stimulus and is not necessarily orienting.
See taxis.
Knobs See stylet knobs.
Koriogamy The impregnation of a female
nematode which possesses a fully developed vagina and
uterus but an immature ovary.
Labial Annule The labial disc.
Labial Basket A wide basket-like
strucrure in the cheilostom that may be supported by six sclerotized curved
plates, e.g. in the dorylaim genus
Carcharolaimus. See cheilostom..
Labial Crown of Papillae
The anterior most circlet
of papillae located on the lips. In forms with six lips two are lateral, two
subdorsal and two
subventral in position.
In forms with other lip conditions they are accorded their respective positions.
See anterior cephalic crown.
Labial Disc (or Labial Disk) The more or less circular font of cuticle about the oral
opening and delimited posteriorly by the first
transverse striation.
Labial Papillae Papillae located on the lips.
See labial crown of papillae.
Labial Pulp Cavity See lip pulp.
Labial Sclerolization
See framework.
Labial Muscles Specialized lip muscles apparently of the same origin as
somatic muscles.
Labial Probola One of three cuticular processes
(extensions) surrounding the mouth in cephalobids, one dorsal and two
subventral; May be supported on a stem-like
peduncle.
Labial Setae The setae of the inner circlet and located
on the lips or close to the mouth.
Labium (pl.
Labia) Lip.
Lacuna A space; generally applied to a
space between the cuticle and the epidermis and underlying muscle created as
a consequence of the cuticle being less contractile and the muscle more
contractile See cervical lacuna(e).
Lageniform Bottle-shaped.
A more or less
cylindrical body with a narrow elongate neck.
Laggard An individual which matures very slowly or
remains under the mature size.
Lamella (pl. Lamellae)
A thin sheet, plate or layer.
Sheet-like process, part or organ.
Lamellate Composed of thin sheets, plates or layers.
Lamelliform Having the form or
composed of thin sheets, plates or layers.
Lanceolate Oblong and tapering to a point.
Lance-shaped. Spear-shaped. See
oblanceolate.
Lancets Shall sharp teeth in the buccal
cavity of some nematodes.
Lancet-shaped Formed like a lance commonly sharply pointed and two edged.
See lanceolate.
Lancinate To pierce a cell or organ, etc. with a
tooth or stylet.
Larva (pl. Larvae)
In the nematological
sense, the immature form of a nematode. See nymph,
juvenile, neotony.
Larval Stages The periods of growth between molts. See
Instar.
Larvated Eggs
Embryonated eggs.
Larviparous Reproducing by bringing forth
living larvae. Ovoviviparous. See
viviparous, oviparious,
fissiparous, reproduction.
Laterad Toward the side and directed away from the
median line.
Lateral Relating to, belonging to, attached to, or situated at the side.
The position on the nematode body situated 90 degrees from the median line
and perpendicular to the anteroposterior axis.
See position. See
Figure 22,
Figure 23..
Lateral
Alae
Lateral or sublateral extensions of the cuticle which extend along the body in
both males and females. See caudal alae, bursa.
Lateral Cephalic Inflations Cuticular
inflations confined to a limited lateral region just posterior to the lips.
See inflation of the cuticle..
Lateral Cords Longitudinal hypodermal thickenings lying in the lateral
position. See cords, dorsal cord, subdorsal
cord, ventral cord, subventral cord. See
Figure 3,
Figure 21.
Lateral Fields A form of cuticular
configuration above the lateral cords.
Lateral gene transfer
See horizontal gene transfer
Lateral Glands Lateral hypodermal glands.
Lateral Grooves Involutions.
Lateral Guiding Pieces Cuticularized
structures which guide the spicule.
See
Figure 5,
Figure 20.
Lateral Hypodermal Glands Two sublateral rows
of unicellular glands lying in the lateral cords and communicating to the
exterior by short ducts through pores in the cuticle. See hypodermal
glands.
Lateral Lines Involutions.
Lateral Membrane A cuticular flap situated on
both sides of the vulval slit in some nematodes.
See epiptygma, vulvar
flap.
Lateral Nerves Nerves originating mostly at
the lateral ganglia. Of a sensory nature with ganglionic
swellings along the lateral cords, supplying a sensory branch to the cervical
papillae when present and enter the lumbar ganglia
posteriorly.
Lateral Organs The amphids.
See organs of the lateral cords.
Lateral Papillae The amphids.
Lateral Pore An opening to the lateral hypodermal
glands. See
Figure 3.
Lateral Ridges A broad longitudinal ridge which covers the lateral cord
and in some forms may be subdivided superficially by involutions. See
longitudinal ridges.
Lateral Wings Longitudinal lateral elevations of cuticle which extend
along all or part of the body, especially from the base of the esophagus to the
anal region. See lateral field.
Lateroanal In the lateral position at the level of
the anus. See position.
Laterodorsal The position on the
nematode body situated 45 degrees from the dorsomedian line
and perpendicular to the anteroposterior axis.
Submedian. See position,
lateroventral. See
Figure 22,
Figure 23..
Laterodorsal Retractor
Spiculi A muscle extending
anteriorly from the manubrium, to the body
wall between the laterodorsal somatic muscle field
and the lateral cord.
Laterosubdorsal The position on the
nematode body situated 60 degrees from the
dorsomedian line or 30 degrees dorsad
from the lateral line and perpendicular
to the anteroposterior axis. See position.
Lateroventral The position on the nematode
body situated 45 degrees from the ventromedian
line and perpendicular to the anteroposterior axes.
Submedian. See position,
laterodorsal. See
Figure 22,
Figure 23..
Lateroventral Retractor
Spiculi A muscle extending
anteriorly from the manubrium to the body
wall between the lateroventral muscle field and the
lateral cord.
Latitude A site in a nematode measured on the meridian of a cross
section.
L.A.Value The logarithm of the concentration in arbitrary units of the
active root diffusate factor and is proportional to
its activity. See log activity values.
Layered See lamelliform.
LC50 The concentration of a chemical at which 50% of the target organisms are killed; for example, 10 mg of chemical per liter of air or water. See lethal concentration.
LD50 The dosage of a chemical,
based on the mass of the affected organism, at which 50% of the target
organisms are killed; for example, 10 mg of chemical per Kg of target
organism tissue. See lethal dosage.
Leachate The dissolved soluble constituents
of a root diffusate and its solvent. See root
diffusate.
Leaching The result of percolating a solvent through
a substrate to dissolve its soluble constituent.
Leaf Blotch Disease
A pathological
condition of Chrysanthemum incited by Aphelenchoides
ritzemabosi.
Leaf Crown The corona radiata.
Leaf Drop A disease condition of fig trees incited by
Paratylenchus hamatus
and Xiphinema index.
Leaf Galls Leaf swelling which serve as structures for the maturation
and reproduction of the nematode parasites and are comparable to seed galls.
Leather-like See
coriaceous.
Lectins Sugar-binding proteins which are highly specific for the sugar component to which they bind. Often involved in biological recognition between cells and proteins.
Lectin Binding The use of sugar-binding proteins to adhere to specific regions of cell walls. For example, some bacteria use lectins to attach themselves to the cells of the host organism during infection.
Lectotype The specimen selected as
holotypc from the syntypes
upon which a species revision is based. See type.
Legs Hollow, glandular ambulatory setae.
Lcmniscate Ribbon-like,
having the shape of an "8". See panduriform,
eight-shaped structure.
Lemon-shaped See citron-shaped. Prolate.
Lenticular Lens-shaped.
Having the form of a biconvex lens.
Leptoderan Caudal alae
which do not meet posterior to the tail. See
peloderan.
Lesion An injury, wound or morbid structural change.
A localized spot of diseased tissue.
Lethal Concentration The concentration of a chemical at which the target organisms are killed; for example, 10 mg of chemical per liter of air or water. See LC50.
Lethal Dosage The dosage of a chemical, based on the mass of the affected organism, at which the target organisms are killed; for example, 10 mg of chemical per Kg of target organism tissue. May be expressed based on ingestion (Oral Lethal Dosage) or skin contact (Dermal Lethal Dosage). See LD50.
Lethargy A state of inaction.
Life Cycle The successive series of changes through which
an organism passes in the course of its development.
See generation.
Life History The record of events in the
development of an individual.
Liganientum
Cephalo-esophageal
arcade cells.
Lighter Striae
Intermediate striae.
Ligneous Wood-like.
Woody.
Limnic Living in aquatic environments with low salt
content. Freshwater environments.
Linear Resembling a line. Having a form long and
uniform in width.
Lineate Having lines or stripes. Having a form long
and uniform in width.
Linguiform Tongue-shaped.
Lingulate Tongue-shaped.
Ligulate Strap-shaped.
Lip Cap The anterior most
cuticular
annulation,
disc-like in shape,
circumoral and usually thicker
than adjacent head annules.
Liplets Diminutive lip-like structures
frequently projecting.
Lipoid Membrane A thin, delicate covering membrane
immediately beneath the egg shell of fertilized eggs. The
inner membrane. See the fertilization
membrane.
Lip Pulp The interior tissue of the lips composed of several large,
elongate cells. See clavate cells, fiber
cells, arcade cells, filling cells.
Lip Region The cuticular area from the basal
ring forward.
Figure 40.
Lip Sclerotizations The cephalic framework.
Lip Sector The several regions of the anterior cephalic region as
delimited by the radial blades.
Littoral Fauna Organisms dwelling between high and low tide lines,
usually close to the shore. See
benthic fauna, pelagic fauna.
Lively See alacrious.
LM Light microscope or light microscopy
Loam The textural class name for soil having a moderate amount of sand,
silt and clay. Loam soils contain 7 to 27 percent of clay, 28 to 50
percent of silt and less than 52 percent of sand.
Lobe A generally rounded part or projection of a part or organ separated
from neighboring parts by fissures or constrictions.
Lobiform Shaped like a lobe or rounded
process.
Lobulate Consisting of or with many small
lobes or lobules.
Locus The specific position on a chromosome where a gene or
genetic sequence is located.
Log Adivity Values A L. A. of zero is that
concentration of hatching factor of root diffusate
which just fails to give a hatch significantly higher than water. A L. A. of I
represents a value of 10 times, a L. A. of 2 represents a value of 100 times,
etc. The logarithm of the concentration of the active factor
of the root leachate.
Longitudinal Extended in length. Lengthwise.
Longitudinal Alae Longitudinal thickenings of
the cuticle, generally lateral or sublateral,
extending the length of the body. See
alae.
Longitudinal Axis The long axis from head to tail.
Anteroposterior axis.
Longitudinal Cords The longitudinal thickenings of the hypodermis. See
cords.
Longitudinal Fibrils
Noncontractile or static fibers of the muscle
sarcoplasm. See
transverse fibrils.
Longitudinal Fields The longitudinal ridges.
Longitudinal Lines The longitudinal ridges of some authors and the
longitudinal cords of others.
Longitudinal Lip Groove A cephalic cuticular
depression above each of the radial blades of the cephalic framework.
Longitudinal Lip Striae Generally faint,
irregularly spaced markings of the cephalic cuticle which terminate at the
cephalic constriction, See constriction.
Longitudinal Markings This form of cuticular
ornamentation may he ridges, alae or the result of
interruptions in the transverse markings.
Longitudinal Plane The lengthwise plane or dimension ala body. See
sagittal plane, transverse plane.
Longitudinal Ribbon The lateral field.
Longitudinal Ribs The longitudinal ridges of the cuticle.
Longitudinal Ridges Local longitudinal
thickenings of the two external cuticular layers
which extend the whole body length. See lateral ridges.
Longitudinal Striation In the cuticle a groove
parallel to the longitudinal axis. See transverse striation.
Longitudinal Thickenings The lateral fields.
The lateral cords.
Lotic Inhabiting rapidly moving
freshwater.
Lumbar Ganglia Large ganglia in the anal region receiving the lateral
nerves and ventrolateral connectives.
Lumen The cavity delimited by the walls of a tubular vessel.
See
Figure 1,
Figure 3.
Lumen Rays The esophageal radii.
Lysigenoma (pl.
Lysigenomata)
A structure formed most commonly
in root tissue by the coalescing of several cells through dissolution of common
walls under stimulation of salivary secretions by
gall-forming nematodes and some other kinds. Giant cell.
See hypertrophy, hyperplasia,
nurse cell.
Lysis Cell destruction. A
tissue dissolution process.
Macerate To waste away. To soften, separate and wear away. See comminute, triturate.
Macrobenthic Invertebrates living within or on the surface
of aquatic sediments and that are larger than 1 mm in size.
Macrophagous Feeding on objects of a
relatively large size. See feeding, microphagous.
Macroscopic Visible to the unaided eye. See
microscopic.
Macula A spot, especially one not elevated above the surrounding level.
See ocellus.
Male Intersex An individual which begins development as a male but,
completes development as a female See
intersex, female intersex.
Male Plant A disease of strawberry incited by
Aphelenchoides fragariae. See
dwarf.
Malformation An abnormal development or formation of a part or
structure.
Mamelon A cuticular projection on the ventral surface, particularly of males of the oxyurid genus Syphacia.
Mammalian Toxicity The effect of a pesticide on non-target human and warm-blooded animals. See Toxicity.
Mammiform
Nipple-shaped. Breast-shaped.
Mammillate
Having nipple-like protuberances or processes. Digitate.
de Man Formula
See De Man Formula.
de Man Indices The De Man formula.
Mandibles Hard, strong
cuticularized structures about the mouth which
function in biting or
grasping.
Manubrium The enlarged,
cephalated proximal portion of the spicule.
See
Figure 16,
Figure 20.
Marginal Fibers Fibers, probably of an
elastic nature, which extend from the ends of the lumen of the esophageal radii
to the bounding membrane of the esophagus.
Marginal Tubes The terminal cylindrical
endings of some esophageal radii; the radii of other forms may have convergent
terminals. See
Figure 13.
Marine Living in the sea. See aquatic,
arenicolous, edaphic,
hypogaeic, limnic, rheophile, terrestrial,
terricolous, xerophilous,
cavenicolous, fossorial.
Marsupials
Mammals with short gestation period that carry young in a pouch; endemic
to Australia
Mass Invasion A situation where large numbers of nematode parasites
attack a host simultaneously.
Mass Hatching The phenomenon of large number of nematode eggs hatching
within a short period of time in response to some stimulus.
Massive Gland A simple roundish pear-shaped cell or an elongate tubular
cell of uniform diameter and devoid of internal cavities.
Salivary gland.
Masticatory Apparatus Organs or
structures adapted to the chewing of food.
Matricin A fibroid segregate of the cuticle
corresponding to the matrix layer. See
cuticular layering.
Matrix The enveloping substance within which something originates or
develops.
Matrix Glands In Meloidogyne
spp. six glands, two subdorsal, two lateral and two
subventral which secrete the
gelatinous matrix through the anus and in which the eggs eventually are
imbedded.
Matrix Layer The cuticular stratum consisting
of a spongy mass between the fibrillar layer and the
boundary layer. See cuticular layering.
Maturation The entire process by which diploid primordial germ cells are
transformed into haploid gametes.
Maturation Division Mitosis.
Mediad Toward the median plane or line.
Medial Pertaining to, directed toward, situated at, or occurring in the
middle.
Median A midway point in position. Situated in the
middle position. A plane of division dividing a
bilateral organism into right and left halves. See position.
Median Bulb The
metacorpus.
Figure 40
Median Esophageal Bulb The
metacorpus.
Median Pseudobulb
The metacorpus.
Medioventral
Ventromedian. See position.
Medium (pl. Media) Substratum.
Meiobenthos The assemblege of microinvertebrates, including nematodes and copepods, that inhabit freshwater and marine aquatic systems.
Meiofauna
Organisms
that pass through a 1-mm mesh sieve and are retained on a 42- or 63-um mesh
sieve
Meiosis The process by which a nucleus halves its chromosome number from
the original diploid state to the reduced haploid state. Typically
meiosis consists of two nuclear divisions: in one,
without prior longitudinal splitting the chromosomes separate resulting in half
of the original diploid number being in each resulting daughter nucleus; in the
other the process is essentially mitotic in character. Four haploid cells are
thus produced by the two divisions.
Meiotic Parthenogenesis Reproduction without fertilization and with a meiotic reduction division of the unfertilized egg cell. Diploid number is re-established by fusion with the nucleus of a polar body. See Parthenogenesis, Automictic Parthenogenesis.
Mensural Of
or pertaining to measure. Measurable.
Menstruum A solvent. Any
substance capable of dissolving a solid body.
Mentek A disease of rice incited by
Hirschmanniella
oryzae.
Meridic Pertaining to a medium in
which the chemical identity of certain, but not all, of the absolutely essential
molecules has been established. Media in which most of such requirements are
known are highly meridic; those in which but
one or a few are known are slightly meridic.
See holidic, oligidic.
Mermithaners Male ants infected with a
species of mermithids. See
mermithogynes,
mermithostratiotes, mermithergates.
Mermithergates Worker ants infected with a
species of mermithids. See
mermithogynes, mermithergates,
mermithostratiotes, mermithaners.
Mermithogynes Female ants infected with a
species of mermithids. See
mermithergates,
mermithostratiotes, mermithaners.
Mermithostratiotes Soldier ants infected with
a species of mermithids. See
mermithogynes, mermithergates,
mermithaners.
Mermithoid Esophagus Having a degenerate
musculature and possessing a long cuticularized tube
with the cells of the esophagus and glands distributed in an irregular manner.
Merogony A mode of reproduction where the
spermatozoon enters the egg cell and provides stimulus to further embryonic
development but does not fuse with the nucleus to form a zygote.
Meromyarian Having eight rows of longitudinal muscle
cell between hypodermal cords. See platymyarian, holomyarian,
polymyarian.
Mesenteries A delicate membrane which invests the intestine and the
gonads and extends from the esophageal membrane to
pseudocoelomic membranes covering the musculature. See
pseudocoelomic membranes, isolation tissue.
Mesenteron The intestine.
Mesorhabdions The walls of the
mesostom.
See
Figure 1,
Figure 10.
Mestostegostom
The second anteriormost region of the stegostom, the mesostom. See mesostom.
Mesostom A subdivision of the
protostom as distinguished by clefts in the
rhabdions and is preceded
anteriorly by the prostom and
posteriorly by the metastom.
See prostom. metastom.
See Figure 10.
Messenger Ribonucleic Acid See mRNA.
Metabarcoding See DNA Metabarcoding.
Metabolic Footprint
A measure of the contribution of an individual, species or guild of
organisms to ecosystem function or service based of
their utilization of carbon and energy. See metabolism, abundance, ecosystem
services.
Metabolism The chemical changes occurring in living organisms by which
energy is provided for vital processes and activities and new material is
assimilated to repair the waste. The sum of the processes of
anabolism and catabolism which take place in living matter.
Metabolites The substrates, intermediates and products of cell metabolism.
Metabolomics
Study of chemical processes invol;ving metabolites. See metabolites.
Metacentric Having two equidistant arms due
to the median position of the centrome. See
telocentric.
Metacorpus The posterior subdivision
of the corpus taking an ovate form and being preceded by a cylindrical anterior
segment. The median bulb. See
procorpus. See
Figure 1.
Metagenesis Reproduction where the immediate
descendants are dissimilar from the parents with the alternate type produced
only with every other generation or after a period of several generations.
The alternation of sexual and asexual reproduction in the
life cycle of certain organisms. Alternation of
generations.
Metagenomics The
study of genetic matterial recovered from an environment or from an
assemblage of organisms. See genomics.
Metameric Segmentation The
repetition of elements of the main organ systems of the body along the length
of the body. For example, in the earthworms (Annelida), each of the
externally visible rings marks a segment (or metamere) of the body that
contains a similar pattern of blood vessels, nerves, excretory organs,
external features, etc.; similar patterns are evident in Arthropoda. In
the Vertebrata, segmentation is most obvious during embryonic development; in
adults it is confined to mesoderm derivatives such as muscle and skeleton,
e.g., repetition of vertebrae and ribs.
Metamorphosis A pronounced reorganization of body tissues and form in changing from one stage of development to another, as from a larva to an adult. See complete metamorphosis, incomplete metamorphosis.
Metaneme
Filamentous organs located in or near lateral hypodermal chords.
Interpreted as stretch receptors,
known in some nematode species, but not C. elegans. Occur in
nematodes of the order Enoplida.
Have a central scapulus and anterior and posterior filaments
Metaphase A stage in mitosis or meiosis when
chromatids are arranged on the equatorial plane of
the spindle. See
prophase, anaphase, telophase.
Metarhabdions The walls of the
metastom.
See
Figure 1,
Figure 10.
Metastegostum
the second last region of the stegastom, the
metastom, See metastom.
Metastom The posterior subdivision of the
protostom as distinguished by
clefts in the rhabdions.
See mesostom,
prostom. See Figure 10,
Figure 40
Metatype In the broad sense, a
specimen compared by the author of a species with the type and determined to be
conspecific. In the narrow sense, a
topotypic specimen compared by the author of a
species with the type and determined by him to be
conspecific. See type.
Myceile, Micella,
Micell In colloids a unit of structure derived
from complex molecules.
Microbenthic Invertebrates
living within or on the surface of aquatic sediments and that are less than
63 um in size.
Microclimate The local climatic condition of a particular niche resulting
from the modification of the general climate
condition by local differences in relief, exposure and cover.
Microfilariae Young or embryonic
filarioids of the
Filarioidea.
Micron (µm, pl. Micra)
A unit of measurement equal to 1/1,000 of a
millimeter, designated by the Greek letter mu.
Microphagous Feeding, on objects of a minute
size. See feeding, bacteriophagous,
macrophagous.
Microplot A small duplicate of a field plot
designed to be as similar as possible.
Microphytobenthos The community of unicellular eukaryotic algae, especially diatoms, and cyanobacteria that at the surface of illuminated marine and freshwater sediments; the primary producers at the base of benthic foodwebs.
Micropyle The minute opening in the investing
membrane of an egg permitting the entry of a spermatozoon.
Microscopic Small in size. Not visible to the
unaided eye. See macroscopic.
Midbody The equatorial region of the nematode body.
Median. See equatorial.
Middle Cuticular Layer This layer corresponds
to the matrix layer of the cuticle, See cuticular
layering. See
Figure 21.
Middorsal The true dorsal line.
Dorsomedian, See
position.
Middorsal Nerve The dorsal nerve.
Midgut The intestine proper, from the
posterior of the esophagus to the anterior of the rectum See foregut,
hindgut.
Midintestine The intestine proper.
Midventral The true ventral line.
Ventromedian, See position.
Midventral Glands Supplements.
Migrate To move from one feeding site or location of development to
another.
Migratory Nematodes
Endoparasitic and
ectoparasitic nematodes
which are capable of feeding and moving about in roots or soil.
Mitosis The process by which a nucleus divides into two nuclei. Typically
mitosis consists of four successive stages; (1) the prophase, in which the
chromatin forms long thread-like structures termed a
spireme (or several spiremes) which shorten,
thicken and split longitudinally becoming rearranged into paired chromosomes;
(2) the metaphase, the nuclear membrane dissolves, a spindle is formed and the
chromosomes come to lie at its equatorial plane; (3) the anaphase, the
chromatids separate and move to opposite poles of
the spindle; (4) the telophase, the chromosomes
uncoil, become elongated and eventually become indistinguishable. A nuclear
membrane is formed and the spindle disappears. Each daughter nucleus contains
the original (diploid) number of chromosomes. If the cell is to divide the
cytoplasm cleaves at this stage. The period of time involved in mitosis varies
greatly but is usually between one-half and three hours.
Mitotic Parthenogenesis
Reproduction without fertilization and by mitotic division of egg cells. See
Parthenogenesis, Apomictic Parthenogenesis.
Modified Changed somewhat in form or other
characteristics.
Molt, Moult
To cast off the cuticle. See ecdysis,
instar.
Moniliform Constricted at intervals so
as to resemble a string of beads. Beaded.
Moniliform Glands In the
demanian system posterior glands which accompany the
ducts which open to the exterior shortly anterior to the anus.
Monodelpbic Having one ovary. See
amphidelphic didelphic,
prodelphic, opisthodelphic,
polydelphic. See
Figure 25,
Figure 26.
Monogenesis Development from a single hermaphroditic
parent. Asexual reproduction. See
reproduction.
Monogenetic Development where the larvae resemble the
parents. See heterogenetic,
reproduction.
Monogony The development of eggs without benefit of
fertilization by spermatozoa. See parthenogenesis, reproduction.
Monograph A treatise in detail on a particular subject.
Monomorphic Exhibiting only one form,
especially applied to species which contain only one sex (female). See
dimorphic, heteromorphic,
polymorphic,.
Monophagous Feeding on only one kind of food,
especially nematodes feeding on plants. See feeding.
Monophyletic Derived, developed or of a
single stock or common ancestral form and including all the descendants of the
common ancestor. See polyphyletic, paraphyletic, polyparaphyletic.
Monophyly A group of organisms exhibiting the monophyletic
condition. See monophyletic, paraphyly.
Monoploid Having the
gametic number of chromosomes. Haploid. See
aneuploid, euploid,
heteroploid. hyperploid,
polyploid.
Monorchic Having one testis. See
diorchic, reproduction.
Monotremes Egg-laying mammals of the order Monotremata; the
only egg-laying mammals.
Monotype A holotype of a species based on a
single specimen. See type.
Monovarial. See Monodelphic.
Monoxenic Pertaining to the rearing of an organism
with only one known species of associated organism. See
gnotobiotic agnotobiotic,
xenic, axenic,
synxenic, dixenic.
trixenic, polyxenic.
Monoxenic Culture A nematode
population containing only one other species of organism. See pure
culture, aseptic culture, agnotobiotic culture,
axenic culture.
Monoxenous Having a single host species in the life cycle.
See Monoxenic.
Moon-shaped See bicorn,
crescentiform, seleniform,
semilunar.
Mordant In staining, any substance which when added to the dyestuff
combines to form an insoluble compound to produce a fixed color in the material
stained.
Moribund In a dying condition.
Near death.
Morphogenesis Development or evolution of morphological characters.
Morphology The study of form and structure of organisms.
Morphometry Measurement of external form. See
De Man Formulae.
Morphometric Parameters Measurement of external form. See De Man Formulae.
Morphotype
The
type of the dimorphic form of a species.
See
type.
Morula The
globular mass of cells formed by holoblastic
cleavage of the egg in its early development.
Morular Organ A region at the
ovarial end of the uterus
where the egg shell is formed.
Mosaic-like See tessellate.
Moult Var. of molt.
Mouth The oral aperture. See
Figure 1.
Mouth Capsule The buccal cavity.
Mouth Spear See
stomatostyle,
ondontostyle. onchiostyle.
MPB See Microphytobenthos
mRNA
Mucivorous Feeding on the protoplasm of plants.
See feeding.
Muck Soil Highly decomposed organic soil material developed from peat. In
gencral, muck has a higher mineral or ash content
than peat and is decomposed to the extent that the original plant parts cannot
be identified.
Mucoid A segregate of the cuticle (glucoprotein).
Mucro An abrupt
point, tip or process which terminates the nematode tail; a cuticular projection.
Mucron A small knob-like ending on a
terminus.
Mucronate Ending abruptly in a point, having
a mucro.
Mucus The gelatinous matrix.
Multispire Two or more turns of a
spriral. See
spiral.
Mural Stylet A stylet
derived from the wall of the stoma.
Mural Tooth A cutting or piercing structure situated on the pharyngeal wall but formed
further back in the esophagus.
Muscle Fibers See fibroplasm.
Muscle Fields The somatic muscles divided into groups by the cords and
named according to position. See dorsosubmedian
muscle fields, ventrosubmedian muscle fields. See
Figure 21.
Muscles of Special Function Muscles of the same origin as somatic muscles
but limited as to region and function. See somato-esophageal
muscles, somato-intestinal muscles, intestinal
muscles, anal muscles, vulvar musculature,
bursal musculature, spicular
muscles.
Musculature The muscles of a body with special reference to their
arrangement and function.
Musculus Bursae
Basalis A bursal
muscle arising from the ventral side of the bursa extending dorsally to the root
of the dorsal ray. See bursal musculature.
Musculus Costae
Dorsalis A much branched bursal muscle
arising mediodorsally in the dorsal ray, extending
anteriorly to become trifurcate then the median arm
splits into four parts. See bursal
musculature.
Musculus Costae
Lateralis Externus Anterior
Bursal muscles arising anterior to the
musculus costae lateralis
externus posterior, extending
posteriorly to the base of the ventral rays. The muscles probably
function to extend the bursa. See bursal
musculature.
Musculus Costae
Lateralis Externus Posterior A
bursal muscle arising
anteriorly dorsad of the lateral cords,
extending posteriorly and becoming trifurcate at the
base of the lateral rays. The muscle probably functions to extend the bursa.
See bursal
musculature.
Musculus Cestrum
Literalism Internist
A bursal muscle arising as paired
sub median muscles at the body wall anterior to the
intestino-rectal valve; each laterally extended
branch enters the root of the lateral ray. The muscle probably functions to bend
the bursa inwards. See bursal musculature.
Mushroom-shaped Stalked with an umbrella top.
Mutant An organism that undergoes mutation.
Mutation A genetic variation with the progeny differing from their
parents in one or more characters.
Mutualism A symbiotic relationship in which all species involved benefit from the interactionm. See symbiosis
Mycophagous Feeding on fungi. See feeding.
Nanism
Dwarfishness.
Being small in stature.
Natatory Parts Structures adapted or used for
swimming.
Natural Enemies Organisms detrimental to the survival
of others.
Natural Selection The process of population or specific stress by the
environment tending to eliminate those forms least adjusted to survive under the
conditions in which they live.
Neallotvpe An allotype
described after previous publication of the original description. See
type.
Near-Cauliflower Intermediate forms of disease expression between the
healthy plant and cauliflower dwarf.
Nearctic Pertaining to or belonging to the
nearctic region.
Nearctic Region That part of the
Holarctic Realm considerd the New World, which covers most of the North
American continent and
Neck That portion of the nematode body from
the base of the lips to the base of the esophagus.
See cervical.
Necrobiosis The death of an individual
cell. See necrosis, nematosis.
Necrobiotic Food Tendencies The
preference of plant cells for food at an early stage of necrosis by pathogenic
nematodes.
Necromenic. Using the feeding strategy that is described by
Necromeny. See Necromeny
Necromeny
Feeding on microbes that exploit the cadavers of dead organisms.
Necrophagy Cannibalism of dead organisms by others of the same species, an effective route of infection of parasitic organisms among hosts..
Necropsy A post-mortem examination.
See
autopsy.
Necrosis The death of cells surrounded by living tissue, specifically
death to cells in mass in contrast to necrobiosis.
See necrobiosis,
nematosis.
Necrotic In a dead and decaying condition.
Affected with or characterized by necrosis.
Nectaries Plant cells near the heads
of sedentary nematodes which have been stimulated to
enlarge by saliva excretions and from which the
nematodes derive their sustenance. Nurse cells, giant cells.
Needle-shaped See acerate,
acerose, acicular, aciform,
spiculiform, spicule.
Negentropy Negative
entropy or reverse entropy;
the opposite of randomness or chaos; a greater degree of
organization and structure, resulting in increase in functions and services
of the system. See Entropy.
Nekton Fauna Animals that swim freely by their own
efforts. See palagic, plankton,
benthos.
Nema A term for any individual of the phylum
Nematoda.
Nemacide See
nematicide.
Nemata An alternative name for the
phylum Nematoda.
Nematicide Any agent lethal to nematodes.
Nematization The state of being
populated, infested or infected with nematodes.
Nematize To populate, infest or infect with
nematodes.
Nematocide Var. of
nematicide.
Nematoda The name of the phylum
constituted by nematodes.
Nematode A term for any individual of the phylum
Nematoda. See eelworm, nema, roundworm,
threadworm.
Nematode Index The numbers of nematodes per unit of substratum:
0 = none = 0
1 = rare = 1
2 = infrequent = 10
3 = frequent =
100
4 = abundant =
1,000
5 = very abundant = 10,000
See root-knot index.
Nematode wool A mass of resistant, desiccated
Ditylenchus larvae frequently found on bulb crops and others.
Wool.
Nematodologist Var. of
nematologist.
Nematological Pertaining to, or having the
character of, nematology.
Nematologist One versed in
nematology.
Nematology The body of science centered on
nematodes.
Nematophagous Feeding on, or deriving
sustenance from, nematode bodies. See feeding.
Nematosis A morbid condition due to parasitism by
nematodes. See necrobiosis.
Nematostat
A chemical, situation or phenomenon which
holds a nematode population in equilibrium.
Nematotoxic
Pertaining to a
nematotoxin.
Nematotoxin Any substance lethal to nematodes.
Nemic Belonging to, or pertaining
to, nematodes.
Nemic Index See nematode index.
Nemicide See
nematicide.
Nemin The substance or substances that
cause trap formation by predaceous fungi. See Endogenous
nemin.
Neodont A tooth emerging at the anterior part of the esophagus in some nemaode taxa, e.g. genus Boehmiella.
Neontology
The study of recent organisms as distinguished from paleontology.
Neoteny
Larval characteristics persisting in the adult.
See reproduction.
Neotony
Sexual maturity in the larval stage.
See
paedogenesis,
reproduction.
Neotropical Realm The biogeographical region encompassing tropical
regions of Central and South America. See Afrotropical Realm,
Holarctic Realm,
Australasian Realm.
Neotype
A specimen from the original type locality designated as a new
holotype.
Plesiotype.
See type.
Nepo Virus A plant virus with polyhedral particles transmitted by nematodes
in the Longidoridae. See Tobra Virus.
Neritic
Fauna
Organisms dwelling below the low tide line to depths of about 600 feet and
subject to some wave action. See benthonic fauna, pelagic fauna.
Nerve Ring A belt, broad and flat in slender nematodes but narrow in
forms with a large esophagus, containing cell bodies of neurons
distributed around it.
The nerve
cells
are generally
too diffuse to be termed true ganglia.
The nerve ring represents the dorsal and ventral connections between the lateral
ganglia. See
circumenteric
ring, circum-esophageal
commissure.
See
Figure 1.
Nests Clusters of nematodes within plant tissue.
Nests
Centers of nuclear division of a syncytial hypodermal cell.
Net-like See reticulate.
Neural Larva Migrans
A zoonotic infection in which humans are an accidental (not definitive) host
for a nematode parasite of animals.The
nematodes cannot mature in humans and cause damage by migrating into the
central nervous system and brain; often caused by Baylisascaris
infection..
See Cutaneous Larva Migrans, Visceral Larva Migrans.
Neuron
(pl.
Neurons) A nerve cell and its series of processes.
Niche A habitat or environment best suited for the survival of the
organism.
Nipple-like
See
mammillate,
digitate.
Noncoelomate
Lacking a true body cavity. See
pseudocoelom.
Non-host Usually used when no varieties of a plant species
support reproduction of a nematode species. For example, Citrus
spp. are non-hosts to Globodera rostochiensis.
See host.
Northern See
septentrional.
Noxious
Injurious.
Destructive.
Baneful.
Nuclear Nests
See nests.
Nucleobase The fundamental units of the genetic code; the
bases adenine (A), cytosine (C), guanine (G) and Thymine (T) are the
constituents of DNA while A, G, C and Uracil (U) are the components of RNA.
See DNA, RNA,
nucleotide.
Nucleoplasm
The protoplasm of the nucleus as distinguished from cytoplasm.
Nucleotide
A molecular component of DNA or RNA comprised of three subunit molecules, a
nucleobase, a 5-carbon sugar (ribose or deoxyribose) and a group of one to
three phosphate molecules. See nucleobase, DNA, RNA.
Nucleus (pl. Nuclei) A well defined and specialized portion of
cellular protoplasm held as being of crucial importance to cell physiology and
heredity. It
usually
consists of
nucleoplasm
bounded by
a
nuclear membrane and composed of 1mm, chromatin and differentiated structures
such as nucleoli. See
Figure 7,
Figure 8,
Figure 21.
Nurse Cells Modified plant cells about the heads of sessile
nematodes
which feed on the cells. See giant cells,
nectaries
Nursery
A center of nematode infestation in plant tissue well
isolated from many population inhibiting pressures.
Nymph An immature individual having the form
characteristic
of the adult. In Entomology "larva" is the term for individuals which undergo
complete metamorphosis and to be distinguished from "larva" in the
nematological
sense which undergo incomplete metamorphosis.
Oar-shaped
See
remiform,
spatulate.
Oblanceolate
Inversely lanceolate.
Oblate Flattened, as a
spheriod
depressed at two opposite poles. See
prolate.
Obligate Parasite An organism only capable of deriving its food from
living organisms. See facultative parasite, facultative saprophyte,
obligate
saprophyte.
Obligate Saprophyte Organisms which subsist on dead organic matter or
from available inorganic material and have no relationship with living cells.
See obligate parasite, facultative parasite,
facultative
saprophyte.
Obligatory Aerobic Requiring the presence of atmospheric oxygen in order
to live. See anaerobic, facultative aerobic, facultative anaerobic,
obligatory anaerobic.
Obligatory Anaerobic Growing only in the
absence
of atmospheric oxygen. See aerobic, anaerobic facultative aerobic,
facultative anaerobic, obligatory aerobic.
Oblique
Slanting.
Inclined.
Oblique
Cuticular
Markings
Conspicuous oblique beneath the cortical layer of the cuticle.
Oblong Elongated.
Obovate
Inversely ovate.
See ovoid.
Obtuse Not pointed. Blunt. See pointed.
Ocellus
(pl.
Ocelli)
An eye spot.
A pigmented spot; possibly associated with detection of light.
See macula.
Ochlesis
Any detrimental condition due to overcrowding.
Ocular
Larva Migrans (OLM) A zoonotic infection of the human eye caused
invasion of the eye by larvae of Toxocara canis (dog roundworm).
See visceral larva migrans, neural larva migrans.
Ocular Micrometer Disc A ruled glass plate used in the eyepiece of a
microscope for measuring minute objects.
Ocular Toxocariasis See Ocular larva migrans
Odontium
(pl.
Odontia)
A
labial tooth (teeth) situated on the pharyngeal wall but formed in the esophagus
and moved forward. See
onchium.
Odontostyle
A stylet terminating with a dorsally oblique aperture.
The
stylet
was derived through evolutionary development from an
odontium
and originates in the esophagus wall. See
onchiostyle.
See
Figure 4. See spear.
Oecology
Var. of ecology.
Oesophagus
Var. of esophagus or pharynx.
Offset Not in line with the body contour or not contioguous with
the axis of an organ, for example, an offset head or an offset spermatheca.
Oligidic
Pertaining to a medium, consisting wholly or largely of crude materials in which
no molecule (other than water) has been established as an absolute nutritional
requirement.
See
holidic,
meridic.
Oligonucleotide Short DNA or RNA molecules that function in the
regulation of gene expression.
See Primer.
Oligophagous
Feeding on a few kinds of food, especially nematodes with a limited host range.
See feeding.
Oligozoic
A habitat having few kinds or numbers of animals.
OLM See ocular larva migrans.
Omasum. The third stomach of a ruminat which receives food from the reticulum and passes it to the abomasum. See abomasum.
Omics Informal description of branches of science with names ending
in -omics and collectively characterizethe translation of pools of
biological molecules into structure and function of organisms. See
genomics, metagenomics.
Omnivorous Subsisting on all types of food, especially feeding on both
animal and vegetable material. See feeding.
Onchiostyle
A feeding structure with an onchium or tooth anteriorly and an extension or
onchiophore posteriorly.
Onchium
(pl.
Onchia)
A
solid tooth (teeth) which was formed "in place" as compared to the
development of an
odontium
in the esophagus then moved forward. See
Figure 4.
Onchus
An onchium.
Onion Bloat A disease of onions incited by
Ditylenchus
dipsaci.
Ontogenetic
Pertaining to the life history or development of the individual organisms.
See
phylogenetic.
Ontogeny
The life history or development of an individual as distinguished from that of
the species and higher groups.
See phylogeny.
Oocyte
A female gamete prior to maturation. See
Figure 27.
Oogenesis
The formation of the egg, its preparation for fertilization and development.
Oogonium
(pl.
Oogonia)
The
first stage in the differentiation of an egg cell from a primordial germ cell.
See OOcyte.
Ooplasm
The cytoplasm of an egg.
Oosperm
A fertilized ovum.
A zygote.
Oosphere An unfertilized ovum.
A female reproductive cell.
Opercular
Plug
A removable covering from the hiatus of some nematode egg shells allowing the
escape of the larva.
Opisthodelphic
Having a single ovary posterior to the vulva. See
amphidelphic,
monodephic,
prodelphic,
didelphic.
See
Figure 26.
Opposed Pertaining to structures that are opposite each other, either
located on each side of the body or directed anteriorly and posteriorly.
Orad
Toward the oral aperture.
Oral Aperture
The anterior entrance into the stoma.
See
Figure 1,
Figure 6,
Figure 22,
Figure 23..
Oral Capsule
The stoma.
Oral Cavity
The stoma.
Oral LD50 The dosage of a chemical, based
on the mass of the affected organism, at which 50% of the target organisms
are killed when the material is ingested; for example, 10 mg of chemical per
Kg of target organism tissue. See Lethal Dosage.
Oral Opening
The oral aperture.
Oral Orifice
The oral aperture.
Order In the systematic arrangement of organisms into groups or
categories denoting natural relationships a category ranking above a family and
below a class. See classification.
Ordinal
Belonging to,
or characteristic of an Order.
Ordinate The vertical line perpendicular to the transverse line
(abscissa) to show by graphic design the relations of two series of facts.
See abscissa.
Ordinate Arranged in rows, such as
cuticular
ornamentations, etc..
Organe
Cephalique
The head cleft.
Organic All carbon compounds derived from living organisms.
Organism
An organic entity so constituted as to carry on the various functions of life.
A living creature.
Organs of Sense See tactile organs,
amphids,
phasmids,
ocellus.
Organs of the Lateral Cords
A
conspicuous series of
gland-like
structures giving the esophagus an appearance of alternate tissues.
Organ Z A muscular organ of unknown function, bearing three or four inner
apophyses,
lying between the
spermatheca
and the uterus. See Figure 24.
Orifice An aperture.
Opening of a tube, duct, etc.
Ornamentation Sculpturing or markings on a body or part.
Orthodromic Proceeding in the usual (direction).
Usually applied to nerve impulses but also to gonad direction in nematodes
Orthokinesis
Variation in generalized, undirected, random locomotory activity caused by
variations in the intensity of stimulation.
Oscillation One complete body swing from one extreme limit to the other
of a nematode
serpentine
movement.
Orthometaneme
Filamentous organs located in or near lateral chord. See
Metaneme.
Osmosis
The tendency of two solutions to equalize by diffusion through a selectively
permeable (semi-permeable) membrane.
See
euryhaline,
stenohaline.
Outer Circlet
The combined cephalic crown of papillae and the outer labial crown by forward
migration of the former.
The external circlet.
See inner circlet. See
Figure 2,
Figure 23..
Outer
Cuticular
Layer This layer corresponds to the external and internal cortical layers of the
cuticle. See
cuticular
layering. See
Figure 21.
Outer Labial
Sited on the distal lip segments.
Outer Labial Bristles Outer
labial papillae which have altered to
bristle-like
structures.
The circlet is considered cephalic by some authors.
See
Figure 22,
Figure 23..
Outer Labial Papillae Sensory papillae situated distally on each lip
segment forming a circlet of six in
primitive
forms. The circlet is considered cephalic by some authors. See inner
labial papillae.
Outer Leaf Crown The corona
radiata.
See Figure12.
Outlet Valve The esophageal lumen at the junction of the
haustrulum
with the esophageal- intestinal canal. See inlet valve. See
Figure 15.
Outstretched Ovary Where all segments of the reproductive tube are in a
straight line. See straight ovary,
recurved
ovary,
reflexed
ovary. See
Figure 27.
Oval
Ellipsoidal.
Having the outline of an egg.
Ovarium
The ovary.
Ovary The reproductive organ of the female which produces the ova. See
testis.
See
Figure 25,
Figure 26,
Figure 27.
Ovate
Oval in shape with the broader end basal.
See ovoid,
obovate.
Ovejector
Var. of ovijector.
Overall Application Broadcast application.
Ovic
Juvenile
Unhatched
first stage larva contained within a deposited egg.
Ovic
Embryo
Term for eggs containing an embryo or larva.
An embryonated egg.
Oviduct A tube which serves for the passage of ova from the ovary to the
uterus. See
Figure 27.
Oviform Having the shape of an egg.
Egg-like.
See
ovoid, ovoidal.
Ovijector
That portion of the oviduct modified to aid in the expulsion of the egg,
generally heavily
muscularized.
Oviparous Producing eggs that hatch after expulsion from the body. See
ovoviviparous,
viviparous,
larviparous,
fissiporous,
reproduction.
Oviposit
To lay eggs.
Ovocyte
An oocyte.
Ovoid Having a shape like an egg. See ovate.
Ovoid, ovoidal
Having the shape of an egg.
Egg-like.
See ovate, oviform.
Ovoviviparous Producing thinly shelled eggs which hatch within the
uterus.
Larviparous.
See viviparous.
oviparous,
fissiparous, reproduction.
Ovum (pl.
Ova)
The
reproductive cell of the female nematode.
An egg.
Oxyuroid
Esophagus
Having a cylindrical shape
anteriorly
and terminated by a basal bulb.
Also termed bulboid.
Paddle-shaped
See
spatulate,
remiform.
spathulate.
Paedogenesis
Reproduction in a larval stage.
See
neotony,
reproduction.
Paedogenetic
Reproducing in the
larval
stage.
Paedomorphism Evolutionary change in a charactyer that is
exhibited in a juvenile stage.
Paired See
didymous.
Palearctic Region
That part of the
Holarctic Realm considerd the Old World, which
covers Asia. See Nearctic Region, Holarctic Realm.
Palmate
Hand-shaped.
Resembling a hand with the fingers spread.
Palps
Specialized labial appendages, apparently for touching, grasping or guiding
material to the mouth.
Panduriform
Obovate with a concavity on either side much like a violin.
Papilla
(pl.
Papillae)
Minute elevations of the cuticle.
Any small nipple-like projection or part.
In general sensory organs.
See
Figure 2,
Figure 5,
Figure 11,
Figure 22,
Figure 23..
Papillary Nerves Six nerves, two
dorsolateral,
two lateral, two
ventrolateral
from the nerve ring to the sense organs of the anterior end consisting of three
circlets
of sixteen members.
Paplliform
Having the shape of a papilla.
Parahemizonid
The hemizonion and similar structures.
Paralectotype
All types remaining after selection of a
lectotype.
See type.
Paraphasmids Thick walled ampullae at the sites of the phasmids.
Paraphyletic Group A group of organisms with a common ancestor and most of the descendants of that ancestor, excluding monophyletic subgroups that are descendants of a later ancesor in the group. See monophyletic, monophyly.
Paraphyly Exhibiting the paraphylectic condition.
See monphyly
Parasite An
organism that
obtains its sustenance wholly or in part from another living organism. See
free-living
feeding.
Parasitic Castration A situation where parasitic nematodes destroy the
gonads or arrest their development, especially in insects.
Parasiticide
Any agent lethal to parasites.
Parasitism An association where one individual lives at the expense of
another,
makes no return and is destructive to its host.
The state of being parasitic.
Paratenic Host A
substitute intermediate host in which the parasite feeds, but does not pass
through developmental stages, until a Definituve Host is reached. See
Definitive Host; Transfer Host..
Paratype
All
specimens
remaining
after the selection of the
holotype
and
allotype.
See type.
Paravulvae Specialized ventral body pores
in females, located anterior and posterior to vulva. See genus
Paravulvus.
Parenteral Feeding
The absorption of food other than by way of the intestine.
See feeding.
Pars Distalis Vaginae The distal part of the vagina with
cuticular lining contiuous with that of the exterior of the body. See
Figure 35.
Pars Proximalis Vaginae The proximal section of the vaginal canal with hyaline walls. See Figure 35
Pars Refringens Vaginae The distal-intermediate section of the vaginal canal, sclerotized, refractive structures varying in shape. See Figure 35
Parthenogenesis The development of eggs without benefit of fertilization by spermatozoa. See Monogony, Reproduction, Sperm-dependent; Meiotic Parthenogenesis; Mitotic Parthenogenesis
Parthenogenetic Having the ability to reproduce by
parthenogenesis. See Parthenogenesis.
Partial Sterilization An incorrect term for selective killing of
organisms in a substrate.
See
Pasteurization.
Partial Striae
Intermediate striae.
Partite Parted.
Separated.
Passive Migration The transport of nematodes by water, wind, on hoofs,
feet and bodies of animals, the activities of man, etc.
Pasteurization The process of selectively killing a particular organism
or group of organisms in a substrate leaving other organisms alive. See
sterilization.
Patent
Open.
Spreading.
Affording passage.
Expanded.
Distended.
See patulous,
prepatent.
Pathogen A disease causing agent. An organism causing suffering (pathos)
to its host.
Pathogenic
Disease causing.
Pathogenicity
Pathological, Pathologic
A diseased condition.
A morbid state due to a disease.
Unhealthy.
Pathology The study of disease, their nature, causes, etc.
Patterns
Cuticular
ornamentations.
Patulous
Open.
Spreading.
Expanded.
Distended.
See patent.
PCR
See polymerase chain reaction.
Pearls White
Heterodera
cysts.
Pear-shaped See
piriform,
pyriform.
Pea-shaped See
pisiform.
Pectinate-shaped
like a comb.
Having narrow parallel projections.
Peduncle A stem or stalk.
A stem-like structure supporting an organ or other structure.
Pedunculate
Set on or attached by a slender stem or neck.
Petiolate.
Pedunculate
Papillae
Genital papillae of male nematodes elevated on little stalks.
Pelagic Fauna
The plankton and nekton animals of the open sea.
Pelagic Zone
The open sea, especially beyond the littoral zone and above the abyssal zone.
Pellicle A thin membrane or film.
Peloderan
Caudal alae which meet posterior to the tail.
See
leptoderan.
Pellucid
Transparent.
Penetrate To pass beyond the surface.
To pass into or through a thing.
To pierce.
See
lancinate.
Peppercorns Galls produced by some species of
Anguina,
especially by A.
tritici
in wheat kernels, See cockles, purples.
Percutaneous
Penetration through the skin.
Perforate To pierce. See
lancinate.
Perianal
Situated or occurring around the anus.
Periaxial
Surrounding an axis.
Peribuccal
Around, enclosing or surrounding the
buccal
cavity.
Perienteric Fluid
Fluid of the pseudocoel.
Perineal
Belonging to the perineum.
Perineal
Pattern
Configurations, especially of
Meloidogyne
spp., on the cuticle surface of the perineum; specific designs are common to
each species. See posterior
cuticular
pattern.
Perineum
The superficial region about the anus.
Perioral
Around, enclosing or surrounding the oral aperture.
Perioral
Cuticle Cuticle of the lip region surrounding the oral aperture, often
demarcated by ridges, incisures, flabella and cornua. See
flabellum, cornu.
Petaloid
Having the form or appearance of a flower petal.
Petiolate
Stalked.
Situated upon a stalk.
pH
A symbol of a scale used to designate the relative acidity of a solution. The
scale ranges from 1 to 14.
pH
7, the midpoint, represents a neutral solution. Numbers less than 7 indicate
increasing acidity; those more than 7 increasing alkalinity.
Phagocyte A
coelomocytic
cell which ingests or absorbs noxious organisms, tissue or detritus.
Phagocytosis
The engulfing and destruction of microorganisms, tissues or detritus by
phagocytic action.
Pharyngeal Bulb A muscular swelling of the esophageal wall around the
buccal
capsule.
Pharyngeal
Caecum The esophageal caecum.
Pharyngeal Collar See pharyngeal sleeve
(preferred term)
Pharyngeal Glands
The esophageal glands.
Pharyngeal Gland Nuclei and Orifices See Esophogeal Gland Nuclei and Orifices.
Pharyngeal Sleeve Extension of pharyngeal tissue surrounding the posterior part of the stoma
.Figure
40
Pharyngo-Intestinal Valve
The esophageal-intestinal valve.
Pharynx The anterior part of the digestive tract with a tri-radiate lumen.
Variation of oesophagus or esophagus..
Pharynx Lumen
The esophageal lumen.
Phasmidial Glands
The precaudal glands.
Phasmids
The lateral caudal papillae connected with the lateral
precaudal
glands.
Paired postanal lateral chemoreceptor sensory organs.
See
precaudal glands, scutellum.
See
Figure 19,
Figure
29,
Figure 41.
Phenotype The visible characters of an organism resulting from the
interaction of genotypic
characters
and
environment.
See
genotype.
Pheromone
Chemicals performing the function of hormones outside the body of the
emitting individuals to to affect the behavior of the receiving individuals.
See kairomone, allomone, synomone, semiochemical.
Phoresy
Phoretic Relationship A symbiotic relationship in which one organism is transported by another. See phoresy.
Phyllophagous
Feeding on leaves, See feeding.
Phylogenic,
Phylogenetic
Relating to the lineage history of the development of a natural group.
Phylogeny The lineage history of the development of a genus, family,
class or other natural group. See ontogeny, speciation.
Phylum (pl. Phyla)
In
the systematic arrangement of organisms into groups or categories denoting
natural relationships a category ranking above a class and below a kingdom.
See classification.
Physiological Race, Physiologic Race
See race, hostic race.
Phytocidal
Lethal to plants.
See
phytotoxic.
Phytocide
Any agent lethal to plants.
Phytonematode
A plant parasitic neniatode.
Phytoparasite
Nematodes capable of obtaining sustenance from plants.
Phytophagous
Feeding on the tissues or juices of plants.
Herbivorous.
See feeding.
Phytotoxic
Injurious or lethal to plants.
See
phytocide.
Phytoxic
Phytotoxic.
Piercing Organ
See stylet, odontia, jaws, spines, denticle, lancinate.
Pilliferous
Hairy.
Pioneer A biotype.
A mutation or an adaptation through selection of a nematode population feeding
on a nonhost.
Piriform
Pear-shaped. See
pyriform.
Pisiform
Having the size and shape of a pea
Plankton Organisms that float and move passively with winds and currents,
generally of microscopic size. See pelagic, nekton,
bethos.
Plant-Inhabiting Nematodes
Two different biological groups which can be distinguished as parasites and
saprozoites.
See feeding.
Plaques An inflated condition of the cuticle with the general appearance
of looking like deep annulations divided longitudinally.
See
inflation of the cuticle, warts.
Plate-like
See
disc,
clintheriform.
Platymyarian
A type of muscle cell between the hypodermal cords in which the muscle fibers are all adjacent to the
hypodermis . The platymyarian meromyarian arrangement of somatic muscle cells is
most common in nematodes.
See meromyarian, polymyarian, coelomyarian,
circomyarian.
See
Figure 8.
Plectanes
Cross striated
cuticular
plates
which function to support genital papillae of some males.
Plectoid
Having
the characteristics of the genus Plectus.
Plesiotype
A specimen upon which subsequent or additional description or figure is based.
See type.
Plesiomorphy; Plesiomorphic Character or Trait A character that is unique to a group or species and that may have occurred near to that found in the ancestor; an ancestral trait.
PLFA See phospholipid fatty acid.
Plicate Bearing folds or parallel ridges. See ridge.
Plicatulate
Minutely ridged.
Ploidy
The condition of being a multiple of a basic haploid number.
Phiricellular
Many celled.
Point The apex of
anthing
having a tapering end.
See
apex, mucro.
Pointed See
acunate,
acute, acuminate,
acurninose,
cusp,
aciforin,
obtuse.
Polar Body One of the daughter nuclei derived from the first or second
division of meiosis containing practically no cytoplasm and is expelled from the
oocyte.
Polar Filament A projection of the protein
membrane
on some nematode eggs, probably serving in attachment.
Polydelphic
Having three or more gonads. See
amphidelphic.
monodelphic,
prodelphic,
opisthodelphic,
didelphic.
Polygamous Mating with two or more females. See reproduction.
Polymerase Chain Reaction, PCR Repeated heating and cooling thermal
cycling that facilitates DNA melting and enzyme catalyzed DNA replication so
that large quantities of a specific DNA sequence are produced in a short
time.
The process reuires Primers and DNA Polymerase. See Primer, DNA
Polymerase.
Polymorphic, Polymorphous Occurring in two or more forms. See
dimorphic,
heteromorphic,
monomorphic.
Polymyarian
The presence of
many rows of longitudinal muscle
cells between hypoderal cords; best viewed in transverse body section. See
holomyarian,
meromyarian.
Polyparaphyletic
A paraphyletic groupin from which many monophyletic groups are exclyded. See
polyphyletic, monophyletic.
Polyphagia
The ability to subsist on various kinds of food.
See feeding.
Polyphagous
Feeding on many kinds of food, especially nematodes feeding on decaying organic
matter.
Plant pathogenic nematodes feeding on two or more hosts.
Polyphagy
The ability of plant-pathogenic nematodes to subsist on two or more host plants.
See feeding.
Polyphyletic Group Derived from two or more ancestral types, races, families,
in which common characters are convergences from different ancestors. See
monophyletic, paraphyletic.
Polyploid
Having
a chromosome
number in multiples of the basic haploid number. See
monoploid,
aneuploid,
euploid,
heteroploid,
hyperploid,
diploid.
Polyploidy A
polyploid
condition..
Polyxenic
Pertaining to the rearing of an organism with many other known species of
associated organisms.
See
gnotobiotic,
agnotobiotic,
xenic,
axenic,
synxenic,
monoxenic,
dixenic.
trixenic.
Ponding
A problem of
puddling
in applying large quantities of
nematicide
carrying liquids due to the compacting of the soil surface layers.
Population The individuals inhabiting a specific unit of substratum.
Population Density
The number of individuals per unit of substratum.
Pore A minute opening or orifice; generally the outlet of a gland.
Pore
Space
The space within soils not occupied by solid particles.
Port Of Entry Point of penetration of a parasitic nematode through either
natural or
unnatural
openings.
Position The site of
attachment
of an organ or part. See lateral,
laterodorsal,
dorsoventral,
submedian,
anteroposterior,
dorsolateral,
subdorsal,
laterosubdorsal,
subventral,
ventrolateral,
lateroventral,
sublateral,
dorsomedian,
median,
ventromedian,
postanal,
posterior, anterior,
anteroventral,
medioventral,
preanal,
postanal,
lateroanal.
anterodorsal.
See
Figure 22,
Figure 23..
Possum Ears A disease of strawberry incited by
Aphelenchoides
fragariae.
See
dwarf.
Postanal
Posterior to the anus.
See position.
Postanal
Pulvillus
A
satiation
where the ventral cord passes o both sides of the rectum and is then continuous
with swollen cells on the dorsal surface of the rectum.
Postalar Tail
That segment of the tail posterior to the bursa.
Postcyclic
Host In most cases non-hosts that have acquired a parasite (usually
in the intestine) by prefation on the definitive host, intermediate hos or
paratenic host. See Definitive Host, Intermediate Host, Paratenic
Host.
Postembryonic Pertaining to the life stage after hatching from the egg.
Postembryonic Development
Growth after hatching from the egg.
Posteriad
Directed backward.
Opposed to anteriad.
Posterior
On or toward the hind end of a body or part.
See anterior.
Posterior Adhesion Tube A tube for sececreting
adhesive material located in the poseterior region of the body. See
adhesion tube.
Posterior
Cephalic
Crown
A circlet of four sub- median setae or papillae located immediately posterior to
the anterior cephalic crown or fused with it in some forms. See anterior
cephalic crown, labial crown of
papillac.
Posterior
Cephalid
The second
cephalid
at which the two median cords arise. See
cephalids.
See Figure I.
Posterior Cuticular Pattern The perineal pattern.
Posterior Uterine Branch The postvulvar uterine branch.
Post Mortem After death, especially an examination. See necropsy,
antemortem.
Postrorse In a backward or downward direction. See antrorse.
retrorse,
Postpudendal With genital tube posterior to vulva. See
antepeduntal.
Postuterine A position posterior to the uterus.
Postuterine Rudiment The postvulval uterine branch.
Postuterine Sac See postvulval uterine sac.
Post-uterine Sac
See postvulval uterine sac.
Postvulvar Posterior to the vulva.
Postvulval Ganglion A ganglion which receives the paired ventral nerve
cords at a point posterior of the vulva where fusion into a single nerve cord
occurs.
Postvulval Rudiment The postvulvar uterine branch. Postvulvar Sac The
postvulvar uterine branch.
Postvulval Uterine Branch A rudimentary extension of the posterior
uterus, See Figure 25.
Postvulval Uterine Sac A rudimentary extension of the posterior uterus
which sometimes functions as a spermatheca, sometimes postuterine sac or
postvulval sac.
Potato
Sickness
A disease of potato
incited by Globodera
rostochiensis.
Praeapical Glands
The phasmids.
Praecaudal Glands
Var. of precaudal glands.
Praecorpus
Var. of procorpus.
Praerectum
Var. of prerectum.
Preadult
The
last larval stage before becoming adult.
Preanal
Anterior to the anus.
See
position.
Preanal
Ganglion
A ganglion which receives the Ventral nerve cord and from which the
anolumbar
connectives extend to the lumbar ganglia.
Preanal
Sucker
A greatly enlarged genital papilla having a
sucker-like
form.
Preanal
Tubes
The
cuticularized
ducts of the
preanal
ventral glands.
Precaudal
Glands
Two
organs situated in the lateral
sectors
of the tail. The openings to the exterior are
termed
the
phasmids.
Phasmidial glands.
Precociousness The presence of reproductive structures in
preadult
forms.
See
neotony,
paedogenesis,
reproduction.
Predaceous Living by preying on other organisms.
See
feeding.
Predacious Fungi
Fungi with
the capacity to capture
nematodes
and derive sustenance from them.
Predator A nematode which lives by preying on other nematodes or
organisms. See generalist predator, specialist predator.
Predigestion
The digestion or partial digestion of food outside the intestine.
See
extraoral
digestion,
extracellular
digestion,
intracellular
digestion.
Preferred Host
A plant affording a more favorable environment to a nematode parasite than other
suscepts.
Prepatent
The condition or situation preceding the patent condition.
Preputal
Fold
A
campanulate
fold of cuticle directed
posteriorly
over the tail of some male
forms.
Prerectum
The segment of the alimentary tract between the intestine and the rectum,
separated from the intestine by
a
stricture in the lumen and from the rectum by a sphincter muscle.
See
Figure 18.
Pressure The stresses endured by a nematode population in its struggle
for survival.
See
stress.
Pressure Orifice System A method of applying liquid
nematicides
to soil utilizing pressure, orifice diameter and tractor speed for various rates
of application.
Primary Axil A cleft or depression between two
lips that alternates with the spacing of the labial probola. There are two
sub-dorsal and one ventral primary axils; the spaces may contain one or two
guard processes. See secondary axil, guard process, labial probola,
Figure 36.
Ptimary Host The host in which a parsite completes its lifecycle and reproduces. See secondary host, intermediate host; definitive host.
Primary Muscle Fields The somatic muscles as divided into four main
groups by the cords.
The
dorsosubmedian
muscle fields and the
ventrosubmedian
muscle fields.
See
Figure 21.
Primitive Character
Persisting in structure little advanced from ancestral form. See
primordial, plesiomorphic, derived character.
Primordial
Growth of an individual or organ in its earliest or primitive form.
Primordial Germ Cell Cell at begginning
of ovary where divison of oggonia is initiated. See Cap Cell.
Primordium
(pl.
Primordia)
The initial development of an organ, tissue or individual.
Probolae
Prominent and elaborate specialized extensions encircling the oral aperture
especially in cephalobids;
situated in some nematode forms in labial and cephalic positions.
See
pseudolabia,
cephalic tubers. labial probola. See Figure
11, Figure 36.
Process A prominence or prolongation of a surface.
An outgrowth or extension.
See
apophysis,
corniform,
excrescence.
Procorpus
Tue anterior subdivision of the corpus taking a cylindrical form and generally
being terminated by an oval posterior segment.
See
metacorpus.
See
Figure 1.
Proctodaeum
The
invagination
of the
epiblast
that produces the anus and intestine.
Prodelphic
Having a single ovary anterior to the vulva. See
amphidelphic,
monodelphic,
opisthodelphic.
See
Figure 25.
Progeny
Offspring.
Young.
See reproduction.
Prolate
Elongated, s a spheroid stretched out in the direction of the two opposite
poles. Lemon-shaped.
Proliferative Cell
The
terminal cell.
Prolongation
Stylet
extensions.
Promoter A DNA sequence to which proteins and RNA polymerase bind
that initiate transcription of RNA from the downstream DNA.
See RNA Polymerase.
Pronucleus
(pl.
Pronuclei)
A gamete nucleus after maturation is completed. Two haploid gamete
pronuclei
fuse to form a diploid zygote nucleus in fertilization.
Propagate To continue or multiply
by bearing young, seeds or cuttings and the like. See reproduction.
Prophase The initial stage of mitosis or meiosis in which chromosomes
appear. See metaphase, anaphase,
telophase.
Prorhabdions
Walls of the
prostom.
See
Figure 1,
Figure 10.
Prostatic Glands
Glands
in some male nematodes which produce an adhesive secretion at the distal end of
the ejaculatory duct.
Prostegostom The most anterior region of the stegostom, the prostom.
Prostom
The anterior subdivision of the protostom.
See
mesostom,
metastom.
See
Figure 10.
Protandrous
Hermaphroditism
Spermatozoa and later ova are produced by the same gonad.
A syngonic female.
See reproduction.
Protandry
The production of spermatozoa and later ova by the same gonad. See
reproduction.
Protein A very complex organic compound built of numerous amino acids and
which form an
essential part of the structure and diet of all animals. Protein contains
nitrogen, carbon, hydrogen, oxygen and usually sulfur.
Protein Membrane The outer covering of the egg surface sculpturing of some and it is deposited by the uterine wall.
Proteome The complete set of proteins produced in a cell.
Proteomics
The systematic large-scale analysis of proteins of a cell or system.
Proterotype
The primary type which includes all the material upon which the original
description is based.
See type.
Protoplasm The basic substance of which all living matter is
made,
being grayish, semitransparent, viscid and a complex colloidal physiochemical
system that constitutes tile living matter of plant and animal cells.
Protorhabdions
The walls of the protostom.
See
Figure 1,
Figure 10.
Protostom
The middle region of the stoma delimited
anteriorly
by the
cheilostom
and
posteriorly
by the
telostom.
The
protostom
is
subdivisible
into three parts: the
prostom,
mesostom
and
metastom.
See
Figure 10,
Figure 40..
Protostoma
Var. of protostom.
Protract To extend or
protrude.
Protractor
Gubernaculi
Paired
gubernacular
muscles which extend from the
subventral
body wall anterior to the proximal part of the
gubernaculum.
See
gubernacular
muscles.
Protractor Muscle A muscle which functions to extend an organ. See
Figure 5.
Protractor Onchii
The protractor muscle of the stylet.
Protractor
Spiculi
Paired
spicular
muscles extending obliquely from the
spicules
to the ventral side of the body. See
spicular
muscles.
Protractores
Spiculorum
See protractor
spiculi.
Protuberance An elevation above the surface,
A
protrusion or bulge.
Prouterus
A situation where the proximal end of the uterus is separate and may function as
a receptacle or shell gland.
Provisioning
Services Ecosystem services that provide products whicht support or
maintain life. For example, food, fiber, fuel, energy,
pharmaceuticals.
Proximad
Toward the proximal end.
Proximal Designating that end of a part or organ nearest to the point of
attachment or origin.
Psammal A sandy soil environment or habitat.
Pseudobulb
A swelling of the esophageal musculature in which the lumen does not widen to
form a cavity.
A nonvalvate esophageal bulb.
See true bulb.
Pseudocoel
The
pseudocoelom.
Pseudocoel Cells
Coelomocytes.
Pseuocoelocytes
Coelomocytes.
Pseudocoelom
The body cavity of the nematode.
See
pseudocoelomic
membranes, mesenteries,
coelomocytes,
body
cavity.
Pseudocoelomate Possessing a body cavity that is not entirely surrounded
by mesoderm.
Pseudocoelomic
Membrane A
delicate sheath which invests and supports the internal organs,
specifically it surrounds the esophagus, lines the internal surface of muscle
cells and extends between each pair of muscle cells to the hypodermis. See
mesenteries.
isolation
tissue.
Pseudogamy
Activation of development of an oocyte by a sperm without nuclear fusion, also
known as sperm-dependent parthenogenesis.
In most cases of pseudogamy, the sperm is obtained by copulation with other
species.
See Sperm-dependent Parthenogenesis, Auto-Pseudogamy..
Pseudolabia
Prominences of the head often elaborately developed. They are situated in labial
and cephalic positions in some nematode forms.
See
probolae,
cephalic tubers.
Pseudonchs
Structures in the pharynx which resemble
onchia
in certain views.
Pulvillus
A
cushion-like
group of cells.
See
postanal
pulvillus.
Punctations
Small pits or deep depressions on the surface of the cuticle; the shape is
usually rounded but
may
wary.
Purples Galls produced by some species of
Anguina,
especially by
A.
tritici
of wheat kernels.
See
cockles, peppercorns.
Pure Culture A nematode population containing a single species only; it
differs from aseptic culture by not being free of other organisms.
See
pure population,
agnotobiotic
culture,
monoxenic
culture.
axenic
culture, pure line population.
Pure Line Population A nematode population derived from a single parent
or set of parents.
Pure Population A nematode population containing a single species only;
it differs from aseptic population by not being free of other organisms.
PUS See postvulval uterine sac.
Pustule
A small
papilliform
or
blister-like
elevation.
Putrifaction
The process of organic decomposition especially the anerohic breakdown of
proteins.
Pyriform
Pear-shaped.
See
piriform.
Quadricolumella
In the female gonad probably the gland region that secretes the egg shell.
See Crustaformeria.
Quarantine A restraint upon goods, animals, plants or other materials
which may bear pathogenic organisms.
Race
A
hiotype
or groups of biotypes which differ from one another in certain physiological
characters which function to segment the species into
subspeciflc
categories.
A population which reacts differently than other populations of apparently the
same species.
See
hostic
race.
Rachis An axial structure or column.
Radial Developed or situated around a central axis.
See
actiniform.
Radial Bars
In the cephalic framework six rigid supports connecting the vestibule of the
stylet guide and the basal ring and ribs.
See
Figure 6.
Radial Blades The radial bars.
Radial In Form
See actiniform, stellate, triradiate.
Radial Muscles
Muscles
of the
esophagus which
dilate the lumen of the esophagus.
Ramified Branched..
Ramiform
Resembling or-shaped like branches,
Ramified.
Random Movement
Having a haphazard course or direction in contrast to a tactic response. See
taxis.
Rapacious Feeding on prey.
Predaceous.
Voracious.
See feeding.
Rays
Genital papillac and their accompanying muscles embedded in the bursa of some
nematode forms.
Rays
The esophageal radii.
rDNA Ribosomal DNA are sequences encoding for ribosomal RNA and which regulate transcription of DNA to RNA. They contain transcribed and nontranscribed spacer segments. See DNA, RNA. 18S rDNA is the ribosomal DNA sequence containing genes that encode for ribosomal RNA (See rRNA). Sequence data from these genes is widely used in molecular analysis to reconstruct the evolutionary history of organisms as it is conserved and considered suitable for constructing evolutionary divergences.
Receptaculum Seminis
The spermatheca.
Reciprocally Infective
Capable of transferring from one crop to another then return to infect the
original crop.
Rectal
Commissure
A
commissure
arising from the
preanal
ganglion and extending to the
dorsorectal
nerve.
Rectal Cuticle
The cuticular lining of the rectum which differs in some respects from the
external cuticle.
See external cuticle, esophageal cuticle,
cloacal
cuticle, vaginal cuticle.
Rectal Glands
Large unicellular glands, usually three in females and six in males.
Rectal Matrix Glands
See matrix glands.
Rectal Muscles Specialized muscles which function to widen the anal
opening and are attached to the dorsal wall of the rectum.
Rectal Sinus A cavity immediately
anterior
to the anus and to which the rectum is connected. See
Figure 28.
Rectilinear Formed of straight lines or
characterized by
straight lines.
Rectum A narrow
tube,
flattened in
dorsoventral
direction and separated from the intestine by a sphincter muscle. It is derived
as an
invagination
of the epidermis and is lined by a
cuticularized
intima.
The hindgut.
See
cloaca.
See
Figure 18,
Figure 41 .
Recurved
Reflexed.
Recurved
Ovary
A situation where the distal portion of the
gonoduct
is turned back on itself.
Recurved
ovaries
are considered to belong to the more
primitive
type of ovary. See outstretched ovary. See
Figure 26,
Figure 27.
Red Plant A disease of strawberry incited by
Aphelenchoides
fragariae.
Red Ring
A disease of coconut palm incited by
Bursaphelenchus (Rhadinaphelenchus)
cocophilus.
Reduction Division
See meiosis.
Reflexed
Turned or folded back upon itself, especially applied to configuration of ovaries and testes of
nematodes. See
Figure 26,
Figure 27.
Regenerative Power
The ability to heal wounds.
Regulating Services Ecosystem services that regulate other
ecosystem processes. For example, activities and abundance of pest and
disease organisms, decomposition of organic wastes, purification of water
and air.
Relax To inactivate
nematodes,
generally by heat prior to fixing.
To kill.
Remiform
Having a shape like an oar. See
spatulate,
spathulate.
Renette
Generally one but, in some forms, two
ventral
excretory cells.
The excretory gland.
Reniform
Having the shape of a kidney.
Replacement Spear
Present in
juvenileDorylaimoidea. Located in the anterior,
slender portion of the esophagus..
Reproduction
The process of perpetuating the species by giving rise to offspring. See
neotony,
paedogenesis,
monogony,
parthenogenesis,
digonic
hermaphrodite,
syngonic
female,
syngony,
protandrous
hermaphroditism,
syngenesis,
polygamous, progeny,
protandry,
sex determination, sexual
dimorphism,
syngenesis.
androgynous,
dioecious,
diorchic,
monorchic,
dimorphic, hermaphrodite, precocious, monogenetic, hetero genetic fissiparous,
bisexual,
gyandromorph,,
heteronomy,
larviparous,
ovoviviparious
viviparous,
oviparious,
monogenesis.
Reproductive System All the organs and structures concerned in the
production and delivery of ova and sperm.
Reservoir A plant parasitic nematode population surviving on a "weed"
host.
A cavity or ampulla for the storage of a fluid or secretion.
Resistance The ability of an organism to remain relatively unaffected by
a disease due to possession of certain inherent properties. A host may be
slightly, moderately or highly resistant.
The reduced rate of parasite reproduction on a host.
Resistant Stage
That period of a nematode life cycle in which environmental extremes have little
or no affect.
Resister The species biotype capable of withstanding the adverse affects
of parasites, climate, resistant hosts, etc.
Respiration The absorption of oxygen from the surrounding medium and
giving off carbon dioxide and other products formed by oxidation in the tissues.
Restiform
Corded or cord-like.
Reticulate Having cross markings like a net.
Rectractor
Gubernaculi
Muscles extending from the distal part of the
gubernaculum
to the dorsal or lateral walls of the body.
Retractor Muscle
Muscles which serve to return an organ to its original position.
See Figure 5.
Retractor
Spiculi
Paired muscles extending from the
manubrium
of the
spicule
anteriorly
to the hypodermis near the lateral cords. See
spicular
muscles. See
Figure 5.
Retroarcuate
Curved backwards.
Retrocession
A recession or movement backward.
Retrogressive Development A simplifying evolutionary trend of an organism
usually expressed as the complete or partial loss or amalgamation of structures.
Retrorse
In a backward or downward direction.
Retrovesicular
Ganglion
The union immediately posterior to the excretory pore where the
dorsolateral
nerves fuse.
Reviviscent
Capable of reviving, especially some nematode forms after a period of
desiccation.
Rhabdions
The thickened curticular walls of the stoma.
See
cheilorhabdions,
protorhabdions,
telorhabdions.
See
Figure 1,
Figure 10.
Rhabditiform
Having the shape of a rod.
Rhabditoid
Having characteristics of the genus
Rhabditis.
Rhabditoid
Bursa
A condition where the caudal
alae
meet
posteriorly
and
anteriorly
forming a complete oval.
A wide caudal bursa.
Rhabditoid
Esophagus
Antcriorly
of a cylindrical shape, often with a
pseudobulb,
followed by the isthmus and terminated with a basal bulb.
Rheophile
Inhabiting rivers
and streams.
See
hypogaeic,
aquatic.
edaphic,
marine, terrestrial,
terricolous,
xerophilous,
cavernicolous,
fossorial,
arenicolous,
xiphilous.
Rheotaxis
A situation where the tactic response is dependent upon the mechanical
stimulation of a moving fluid, especially water, for the directive factor.
See
taxis.
Rheotropism
A situation where the tropism is dependent upon the mechanical stimulation of a
moving fluid, especially water, for the orientating factor.
See
tropism.
Rhizosphere
The area
immediately surrounding
the plant roots.
Ribonucleic Acid See RNA
Ribosomal DNA See rDNA.
Ribosomal RNA See rRNA.
Ribosome The cell structure that is the site of
protein synthesis.
Ribosomal RNA (See rRNA) decodes messenger RNA (See mRNA)
into amino acids
Ribs
In the cephalic framework, six rigid supporting structures radiating
transversely, then posteriorly to fuse with the anterior edge of the basal ring
and the six radial bars.
Four ribs are
sublateral,
one dorsal and one ventral.
See
basal ring, radial bars,
cephahc
arches.
See
Figure 6.
Ridge A raised line or strip on a surface.
Ringed
See
annulate.
annulose.
Ring Nematode Decline Of Carnation A disease of carnations incited by
Mesocriconema xenoplax.
Ring-shaped
See
circinate.
Ripe Pertaining to mature ova or spermatozoa.
River Inhabiting
See
rheophile.
RNA
RNAi
rRNA Ribosomal ribonucleic acid is the RNA component of the ribosome (See ribosome). It provides a mechanism for decoding messenger RNA (See mRNA) into amino acids by interacting with transfer RNA (See tRNA) which transfers the amino acids that correspond to the mRNA codon. 18S rRNA is the structural RNA which codes for the small subunit of ribosomes in eukaryotes. The genes coding for 18S rRNA are referred to as 18S rDNA (See rDNA).
RNA Polymerase An enzyme that synthesizes RNA from a DNA template.
Rod Border
Structures on intestinal epithelium which are probably modified immobilized
cilia.
Rod-like
See
baculiform,
rhabditiform.
Rogue To remove undesired individual plants from a crop.
Root Ball The interwoven network of plant roots of a potted plant.
Root
Diffusate
A root excretion that affects the behavior of plant parasitic nematodes,
especially as a hatching or tactic stimulus,
See
leachate.
Root Galls A pronounced localized swelling of root tissue due to
hypertrophy and hyperplasia incited by nematode feeding.
Root-Knot Index
An index of the amount of root galling as a measure of the
Meloidogyne population:
1 = zero percent roots galled
2 = 1 to 25 percent galled
3 = 26 to 50 percent galled
4 = 51 to 75 percent galled
5 = 76 to 100 percent galled
See
nematode
index.
Rootlet A small root.
Root Rot Complex A morbid condition of roots and root tissues incited by
multiple attacks of nematodes, fungi, bacteria, etc,
in
stages or nearly simultaneously.
Root Zone
See
rhizosphere.
Rosette A pathological condition where the internodes of plants are
shortened and the normally separated leaves are closely clustered.
Rosette The
uvette
of the
deManian
system.
Rosettes
Punctation
patterns
of the
cuticle surrounding genital papillae.
Rostrum (pl.
Rostra)
A beak-like projection ventrad near the proximal end of thespicule,
joining the dorsal and ventral spicular shafts.
Rot Destruction of tissues by decay organisms; frequently after nematode
injury.
Roundworm A vernacular term for any individual of the phylum
Nematoda,
especially as applied to parasites of vertebrates.
See
eelworm,
nema,
nematode.
threadworm.
Row Application The placing
of
a
nematicide
in such a manner that the lethal vapor is effective in a broad band where the
future row crop is to be planted.
See
broadcast application, spot application, drench application, gas application.
Rudimentary A condition of imperfect development.
Development on a primitive level.
Development arrested at an early stage.
Vestigial.
Rudimentary Posterior Uterine Branch A vestigial extension of the
posterior uterus.
A postvulvar uterine branch.
Rudimentary Posterior Uterus A vestigial extension of the posterior
uterus.
A postvulvar uterine branch.
Rugae Ridges formed by folds in the wall of a structure. See Buccal
Rugae
Rugose
Wrinkled.
Rugosissimus
Extremely rugose or wrinkled.
Rugula
(pl.
Rugulae)
A
small wrinkle.
Rugulose
Having fine wrinkles.
Rypophagous
Rhypophagus
Filth-eating.
See
feeding.
Sac
A bag or
sack-like
structure.
A pouch.
Saccate
Sac-shaped.
Contained in a sac.
Sacciform
Having the shape of a sac.
Saccular
Sac-like.
Saccule
A small sac or pouch.
Sack-like
See
sac.
Sagittate
Arrowhead-shaped.
Triangular-elongate.
Sagittal Plane
The median-vertical-longitudinal plane in a bilaterally symmetrical animal or a
section parallel to that plane.
See longitudinal plane, transverse plane.
Sagittiform
Arrowhead-shaped.
Saint John's Disease
A disease of peas incited by Heterodera goettingiana.
Salient Pointing outwards, noticeable, obvious.
Saliva
A secretion o the esophageal glands presumably containing a digestive enzyme.
Salivary Gland The esophageal glands. See
Figure 3.
Sand Individual rock or mineral fragments in soils having diameters
ranging from 0.5 mm. to 2.0 mm. Usually sand grains consist chiefly of quartz
but they may be of any mineral composition. The textural class name of any soil
that contains 85 percent or more of sand and not more than 10 percent of clay.
Sand Inhabiting
See arenicolous.
Sandy Clay Soils of this textural class contain 35 percent or more of
clay and 45 percent or more of sand.
Sandy Clay Loam Soils of this textural class contain 20 to 35 percent
clay, less than 28 percent silt and 45 percent or more of sand.
Sandy Loam Soils of this textural class have 50 percent sand and less
that 20 percent clay.
Sap The juices of a plant cell.
The semiliquid constituents which compose the protoplasm of the plant cell.
The watery solution which circulates through plant vascular tissue.
Saprobiont
An organism which subsists as a saprophyte or saprozoite.
See
saprophage,
feeding.
Saprophage
An organism which derives its sustenance from decaying organic matter.
See feeding.
Saprophagous
Feeding on dead or decaying organic matter. See feeding.
Saprophyte Any organism deriving sustenance from dead or decaying organic
matter. See feeding.
Saprozoic
Pertaining to an animal which derives sustenance from dead or decaying organic
matter. See feeding.
Saprozoite
An animal which derives its sustenance from dead or decaying organic matter.
See feeding.
Sarcophagous
Flesh eating.
See Feeding.
Sarcoplasm
The undifferentiated protoplasm of the muscle cell. See
fibroplasm.
See
Figure 8,
Figure
9.
Scaffold An abnormally heavy, refractive guiding ring.
Scalariform
Bearing markings like the rounds of a ladder.
Scale-like
See imbricate.
Scalloped See crenate.
Scaphiform
Having the shape of a boat.
Scavenger An organism which derives sustenance from the refuse, offal and
decaying matter of other life,
See
feeding.
Sclerite
A hard plate or piece of cuticle.
Sclerotized
A noncommittal term
for
hardened.
dense,
refractive parts of the nematode body.
Sclerotized Vagina See Pars refringens vagianae.
Sculate
Having the shape of a shield.
See
scutiform,
escutcheon-shaped.
clypeiform.
Scutellate
Having a surface divided into
small plate-like
areas.
Scutellum
(pl.
Scutella)
Greatly
enlarged
phasmids
common to some species of the
Hoplolaiminae.
See
Figure 19.
Scutiform
Having the shape of a shield.
See
scutate,
escutcheon-shaped,
cypeiform.
S-E
Pore Secretory-Excretory pore. See excretory pore,
cervical pore.
Second Bulb
The terminal bulb.
Secondary Axil A cleft or depression between two lips that
is in line with a labial probola. There is one dorsal and two sub-ventral
asecondary axils, they are usually broader and shallower than the primary
axils. See primary axil, labial probola,
Figure 36.
Secondary Invaders Any and all organisms found in a host after the
initial attack and injury by the primary parasite.
Secondary Host
The host in which the asexual stages of a parasitic
life cycle take place. See Intermediate Host.
Secretion A useful product produced by a cell or gland.
The act of producing or passage of this product.
See
excretion.
Sector The interval between the cords.
Sedentary Endoparasite
See sedentary nematodes.
Sedentary Nematodes
Nematodes
which become established within or on the roots of host plants i.e. root-knot,
cyst-forming, Cobb's root- knot,
reniform,
etc., where the females remain fixed in position throughout their life cycle.
Sediment Particulate meterial, organic and inorganic, that settles to the bottomof a body of water and may provide habitat and resources for organisms.
Sedimentary Layer See Sediment.
Seductor
Gubernaculi
Paired muscles extending from the proximal end of the
gubernaculum
to the
dorsolateral
walls of the body.
Seed Galls Enlarged ovules converted to a gall and containing nematode
larvae, especially on grasses and cereals.
Segging
In Oats
A disease of oats incited by
Ditylenchus
dipsaci.
See
tulip root.
Segmentation
The
repetition of elements of the main organ systems of the body along the length
of the body. For example, in the earthworms (Annelida), each of the
externally visible rings marks a segment (or metamere) of the body that
contains a similar pattern of blood vessels, nerves, excretory organs,
external features, etc.; similar patterns are evident in Arthropoda. In
the Vertebrata, segmentation is most obvious during embryonic development; in
adults it is confined to mesoderm derivatives such as muscle and skeleton,
e.g., repetition of vertebrae and ribs.
In embryological development the subdivision of the single-celled egg into blastomeres. Cleavage.
Seinhorst
Extraction Technique
A method for the isolation of nematodes from infected
plant material
utilizing funnels, a constant fresh water spray and suitable settling basins.
Seinhorst
Elutriator Apparatus
An apparatus employed for the isolation of nematodes from soil resulting in a
sample relatively free of debris.
Seinhorst
Technique
An elutriation method for quantitative extraction of nematodes from soil.
Seleniform
Having the shape of a full moon.
SEM Scanning electron microscope or scanning electron microscopy.
Semelparity
A species is considered semelparous if it is characterized by a single
reproductive episode before death. See Iteroparity.
Semifenestrate
A situation in some species of the genus
Heterodera
where the
vulval
bridge divides the
fenestra
into two parts.
See
fenestrate,
bifenestrate,
ambifenestrate,
circumfenenstrate.
See
Figure 31,
Figure 32.
Semilunar
Having
the shape of a
halfmoon.
Seminal Receptacle
The spermatheca.
Seminal vesicle
In
male nematodes enlarged tube-
or
pouch-like
structures
which
function
to
store
the semen.
Semiochemical
A chemical substance or substances released by an organism that affects the
behaviors of individuals of the same or of other species. See pheromone,
kairomone, allomone, synomone..
Semivagrant
Nematode forms with mobile larval stages and sedentary parasitic adults.
Senescence
Old.
Aged.
Senility
Old age.
Passed the reproductive stage.
Sensilla Basiconica Cone or peg-shaped sensilla.
Sensilla Pouch
An expansion of the amphidial tube containing the sensory elements of the
sensilla and is
situated posterior to the
amphidial
pouch.
See
Figure 2.
Sensillum
(pl.
Sensilla)
A simple sense
organ,
or one of the structural components of a compound sense organ. The nerve ending
connected with the
amphidial
nerve.
See
Figure 2.
Sensory Elements Stimuli preceptors collectively making up the
sensilla.
Sensory Organ A body structure which functions as a preceptor of stimuli.
Sepsis The state or condition of being septic.
See
asepsis.
Septentrional
Northern.
Boreal.
Septic Contaminated with
microorganisms.
-
See
aseptic.
Septicemia A morbid condition caused by pathogenic bacteria and their
toxins within the body.
Seriate Occurring in a series or periodically.
Serrate
Having
marginal
teeth or notches.
See
dentate.
Sessile
Obligate feeding and reproducing at one fixed site.
Not free to move from one site to another.
Seta
(pl.
Setae) Tactile sensory organs of elongate
cuticular
structure and articulate with the cuticle proper.
A bristle-like protuberance.
An aciculum.
See
tubiform
setae, ambulatory setae, bristle setae,
adhesion
tubes.
Setaceous Bearing setae.
See
setose.
Setiform
Having the form of a seta. Bristle-shaped.
Setose
Bearing setae.
Sex-Determination
The factor or factors which cause the development of an egg into a male or
female nematode.
See
reproduction.
Sex Ratio
The proportion of males to females in a nematode population.
Sexual Dimorphism A difference in form or
stricture
as males and females of the same species.
Sexual Reproduction
Reproduction requiring tile union of male and female gametes.
See
asexual reproduction, syngenesis.
Shaft The main body of the
spicule,
usually
curved
and often bearing a thin flange of cuticle termed the velum.
See
Figure 16.
Sheath A covering enclosing a body, part or
organ
and generally
elongated
in form.
Shields
Interlabia.
Shield-shaped
See
scutate,
scutiform,
escutcheon-shaped,
clypeiform.
Sickle-shaped
See
falcate,
crescentiform,
falciform.
Sieve-like
See
cribriform.
Sigmoid
A
two directional curve-shaped like the letter S.
Signal Peptide A short peptide (usually 16-30 amino acid)
to which newly synthesized proteins, that are destined for secretory
pathways, are attached. They prompt the cell to translocate the protein
towards the cell membrane.
Silt Individual mineral particles of soil that range in
diameter
between the upper size of clay, 0.002 mm., and the lower size of very fine
sand, 0.05 mm. Soil of the textural class silt contains 80 percent or more of
silt and less than 12 percent of clay.
Silt Loam Soil material having 50 percent or more of silt and 12 to 27
percent of clay or 50 to 80 percent of silt and less than 12 percent of clay.
Silty
Clay
Soil of this textural class has 40 percent or more of clay and 40 percent or
more or
silt.
Silty
Clay Loam
Soil of this textural class has 27 to 40 percent of clay and less than 20
percent
F
of sand.
Single Egg Mass Line A nematode population derived from eggs produced by
a single female.
See
pure line population, single larva line, pure population,
pure
culture.
Single
Larva Line
A nematode population derived from an individual juvenile nematode.
Sinuate Wavy.
Sinuous.
Sinuous Having a serpentine or undulant form.
Sinus A curvilinear indentation.
An opening or depression.
A cavity, See antrum.
Sinus Canals Greatly enlarged ducts.
Sinusoidal
Wavy, serpentine, winding in form.
Skeletal Fibrils
The longitudinal and transverse fibrils of muscle cells.
Skeleton The cuticle to which the musculature is attached.
Skin The cuticle.
Skin Glands See lateral glands, cephalic glands, cervical glands,
preanal
tubes, cement glands,
hypodermal
glands.
Slimeflux
Wound sap of trees.
Slow Decline A disease of
citrus
incited by
Tylenchulus
semipenetrans.
Soft Cuticle
A gelatinous, elastic, extensible material that makes up most of the nematode
body covering.
See
hard cuticle.
Soil Borne Nematodes living within the confines of the soil during at
least part of their infective stage.
Soil Chimney Any passage leading to the soil surface allowing
nematicidal
vapors to become
diluted
and escape.
Soil Fumigation
The use of a nematicide to disinfest soil of plant parasitic nematodes.
Soil Inhabiting See
edaphic,
hypogeal,
terrestrial,
terricolous.
Soil Mass Application The fumigation of soil in depth as contrasted to
a surface application.
Soil Porosity The degree to which the soil mass is permeated with pores
or cavities. Porosity can be generally expressed as a percentage of the whole
volume of a soil that is unoccupied by solid particles. in addition, the number,
sizes, shapes and distribution of the voids is important, Generally, the pore
space of surface soil is less than one-half of the soil mass by volume, but in
some soils it is more than half The part of the pore space that consists of
small pores that hold water by capillary is called capillary porosity. The part
that consists of larger pores that do not hold water by capillary and allows
free drainage is called
non-capillary
porosity.
Soil
Sterilant
A
nematicide
with a broad lethal I spectrum i.e. will control nematodes, fungi, weeds, etc.
See control.
Soil Structure The arrangement of primary soil particles into compound
particles or clusters that are separate from adjoining aggregates and have
properties unlike those of an equal mass of
unaggregated
primary soil particles. The principal forms of soil structure are platy,
prismatic, columnar (prisms with rounded tops), blocky (angular or
subangular),
and granular.
Structureless
soils are single grain (each grain by itself, as in dune sand) or massive (the
particles adhering together without any regular cleavage as in many
claypans
and hardpans.
Soil Texture The relative
proportions
of the various size groups of individual soil grains in a mass of soil.
Specifically, it refers to the proportions of sand, silt and clay.
Soil Type A category under soil series based on the texture of the
surface soil. See textural class.
Sole The site of attachment of the special ambulatory setae or adhesion
tubes.
Solid Application
The treatment of soil with a nematicide in such a manner that the expanding
vapor forms a solid carpet throughout the field.
Broadcast application See row application, drench application, gas
application.
Solubilization
A form of colloidal solution where a relatively insoluble chemical is dispersed
in the form of micelles, consisting of alternating molecules of detergent and
water with the inner core being the chemical.
Soma (pl,
Somata