General Characteristics
- Body medium-sized.
- Cephalic framework slight to heavily sclerotized.
- Phasmids prominent.
- Lateral
field with two, three, four, or five lines, sometimes
areolated.
Longitudinal ridges sometimes present on body.
- Tail conoid to subcylindroid, about three times as long as wide (c' = 2
to 4), sometimes with thicker cuticle in the distal portion.
- SEM face view typically with labial disc fused with first lip
annule, and with lateral sectors regressed. The remaining
sub-median sectors give a distinctive quadrangular appearance to the
face view. Papillae often present on submedian sectors.
Head continuous to slightly offset.
- Stylet 15 to 30 µm long, thin to slender, has strong knobs, with
cone about as long as shaft, sometimes needle-like.
- Esophageal glands bound by a membrane into a large basal bulb.
Appear to butt into intestine.
-
Deirids often absent.
Females:
- Diovarial,
amphidelphic, ovaries outstretched, vulva about 50%.
- Tail round.
Males:
Note also Merlinius, Quinisulcius
= (Tylenchorhynchus) etc.
[Ref: Fortuner & Luc (1987), and H. Ferris.]
|
Genus monographed by Allen
in 1955 - 34 species, 22 new species, 12 old or already described. In
1962, A.D. Baker listed 55 species. Sher
listed over 100 species (200 in family and subfamily).
Several related genera are differentiated on the following
characters:
1. Number of lateral
lines;
2. Annulation of cuticle;
3. Shape of lip region and
number of annules;
4. Length of spear;
5. Shape and length of female
tail;
6. Position of hemizonid.
|
|