Rev 11/18/2025
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Tylenchina Tylenchoidea Hoplolaimidae Hoplolaiminae
Hoplolaimus von Daday, 1905
Type species of the genus: Hoplolaimus tylenchiformis von Daday, 1905
Synonyms: Nemonchus (Cobb, 1913) Hoplolaimoides (Shakil, 1973) Basirolaimus (Shamsi, 1979)
Generally large, 1.0 to 1.5 mm long, body straight.
Head trapezoid shape.
Lip region offset from body, wide, anteriorly flattened, with clearly marked annules, and with longitudinal striae.
Photograph by Jon Eisenback, NemaPix.
Lateral field with four lines or fewer, generally areolated at level of phasmids and anteriorly, sometimes with striae irregularly scattered over entire field, rarely not areolated.
Labial framework and stylet massive.
Stylet knobs anchor or tulip-shaped.
DEGO 3 to 10 um from stylet base.
Esophageal glands overlap intestine dorsally and laterally; sometimes gland nuclei duplicated to a total of 6 nuclei; intestine symmetrically arranged between the subventral glands.
Tail short, <2x anal body diameter.
Female: Two genital branches outstretched, equally developed.
Tail short, rounded.
Phasmids enlarged to scutella; erratically situated on body, anteriorly to anus level, and sometimes anterior to vulva level, not opposite each other.
Secondary sexual dimorphism visible in labial region
Esophageal structures smaller in males.
[Ref: Raski and Luc (1987)
H. Ferris.]
Of the 37, or so, species of Hoplolaimus currently described worldwide, nine species are reported from California. Correct identification of these species is important for regulatory purposes and to improve knowledge concerning the diversity of plant-parasitic nematode species infesting agricultural crops. The clarification of the taxonomic status of the Hoplolaimus species requires morphological and molecular comparisons using topotype populations of the species and DNA sequences available in the literature. Such studies are ongoing (Subbotin et al., 2025)
The pest rating level of Hoplolaimus species for California varies with the species. In the California Nematode Pest Rating System, revised and new ratings for H. seinhorsti and H. floridensis have been proposed recently (Martin, 2025 a,b)
Food Sources and Feeding strategies for the genus Hoplolaimus
A genus of plant parasitic nematode whose species, in combination, encompass a very wide host range.
Nematode feeds at some distance from root tip; may have head in root or may invade root completely; therefore, the term 'ectoparasite' is a misnomer - nematode often feeds endoparasitically.
Feeding may cause spongy brown cortical areas or cortex to slough off.
Fortuner, Rev. Nematol. 10(2):219-232 (1987)
Holguin, C.M., J.A. Baeza. J.D. Mueller and P. Agudelo. 2015. High genetic diversity and geographic subdivision of three lance nematode species (Hoplolaimus spp.) in the United States. Ecology and Evolution (2015) 2929-2944.
Martin, H.J. 2025a. California Pest Rating Proposal for Hoplolaimus seinhorsti Luc 1958, Lance Nematode. California Department of Food and Agriculture, Sacramento, California.
Martin, H.J. 2025b. California Pest Rating Proposal for Hoplolaimus floridensis Subbotin et al., 2025, Florida Lance Nematode. California Department of Food and Agriculture, Sacramento, California.
Raski, D.J. and Luc, M. 1987. A reappraisal of Tylenchina (Nematoda) 10. The superfamily Criconematoidea Taylor, 1936. Revue de Nematologie 10:409-444.
Sher, S.A. 1963. Revision of the Hoplolaimidae II. Hoplolaimus Daday, 1905. and Aorolaimus n. gen. Nematologica 9:267-295.
H. Ferris