Syn. Isonchus, Cobb, 1913
Aphelenchus (Aphelenchus) Bastian, 1865.
Metaphelenchus Steiner, 1943
(Description- Goodey & Hooper, )
Aphelenchidae: Body tapering anteriorly. Cuticle transversely
striated. Lateral field with numerous incisures. Deirids present
at about level of the excretory pore. Head slightly offset.
Spear shaft with slight thickenings at the base. Procorpus cylindrical,
constricted slightly where it joins the ovoid median oesophageal bulb which
contains prominent, median, crescentic valve plates. Oesophageal
glands usually with, sometimes without a lobe overlapping the intestine
dorso-laterally and joining the alimentary canal where the nerve ring surrounds
it just posterior to the median bulb. Excretory pore about opposite
nerve ring. Intestine joined to median bulb by a short isthmus about
11/2 body-widths long. Vulva posterior, ovary outstretched, prodelphic;
a post vulval sac present, rather obscure but usually reaching about half-way
from vulva to anus. Vagina with thickened walls. Rectum about
one to two body-widths long. Tail between on and four anal body-widths
long, cylindrical to a rounded end. Phasmids subterminal. Male
with bursa usually supported by one pre-anal and about three post-anal,
subterminal pairs of ribs. Spicules paired, slender, ventrally slightly
arcuate, proximally slightly cephalated. Gubernaculum about a third
as long as the spicules.
(Description- Nickle, 1970)
Definition: Aphelenchidae. Lips slightly offset.
Stylet without basal knobs. Esophageal glands overlap intestine dorsally.
Hemizonid usually present. 3-8 annules posterior to excretory pore.
Body narrowing abruptly behind vulva. Postuterine sac long.
Female tail short, bluntly rounded. Spicules paired slender, not
fused, with minute rostrum. Gubernaculum V-shaped. Male tail with well-developed
caudal alae supported by prominent ribs. Males often rare.
Bionomics: Mycophagous, soil inhabiting.
DNA Sequences Obtained
Type species: Aphelenchus
avenae Bastian, 1865