Diagnosis: Duosulciinae. Body elongate-fusiform, with strong
and regular tapering behind vulva so that width at anus becomes about half
that at vulva. Annules prominent as cuticle folds between them.
Lateral field with two incisures delimiting single narrow but elevated
ridge, which, in SEM, shows 12 or more fine longitudinal lines (subgenera
Malenchus, Neomalenchus), or with four or six incisures making
three or five longitudinal bands on most of body (subgenus Telomalenchus).
Cephalic region elevated, flattened dorso-ventrally but not to a great
extent, elevated with four to six fine annules. Labial plate rectangular,
bearing four cephalic papillae (pits); amphidial slits curved ventrally
and extending for one to two cephalic annules (subgenera Malenchus,
Neomalenchus) along the lateral side of head. Stylet 7-14
um long, with distinct knobs. Precorpus equal to or shorter
than isthmus, postcorpus a muscular bulb with refractive thickenings or
lacking musculature (subgenus Neomalenchus). Basal bulb pyriform
with flat to indented base. Vulva located in a body cavity.
Spermatheca elongate, oval, or bilobed, offset, directed forward.
Vagina straight, not sclerotized, directed inward. Uterus with quadricolumella.
Postvulval uterine sac present. Prophasmids dorso-sublateral, about
one body width anterior to vulva. Tail elongate-conoid to a pointed
or hooked tip. Bursa adanal. Spicules tylenchoid. Gubernaculum
fixed. Cloacal aperture on a cone formed by depression in body at
front and rear; lips narrow, pointed.
(Description- Siddiqi, 2000)