Aphelenchus avenae
Bastian, 1865
Female, length 1/20", breadth 1/454".
External Characters. Body white, tapering very slightly at either
extremity, both of which are rounded. Head having no setae or papillae.
Caudal sucker none. Integumental striae transverse, 1/10000" apart,
easily visible.
Dart 1/1666" long, simple, not knobbed at the base. Oesophagus
1/14th only of total length, having a globular and distinctly muscular
terminal swelling, 1/1000" broad. Intestine, portion next
oesophagus very indistinct; granules scattered, rather coarse and colourless.
Anus 1/666" from posterior extremity. Vulva posterior
to commencement of hinder third of body, 1/77" from posterior extremity.
Excretory duct opening slightly posterior to commencement of intestine.
Male not seen.
Hab. Between the lower sheaths of leaves of oats from stubble-field,
Broadmoor, Berks.
(Description- Bastian, 1865)
0.7-1.0 mm; a = 24; b = 5.1; c = 34; V
= 76
Body almost straight
when relaxed. Lateral fields marked by 10-12 incisures, decreasing in number
toward the extremities.
Lip
region rounded, continuous with head contour. Cephalic framework well
sclerotized, cheilorhabdions very refractive. Spear 25u-28u long, without
basal knobs, its musculature of an unusual type. Cephalids outstanding
with ducts leading to tissues lying beside corpus of esophagus and probably
terminating in the nerve ring. Esophageal lobe dorso-submedian, 2
to 3 times as long as body width. Ovary outstretched, variable in length,
sometimes reaching almost to esophagus, with oocytes arranged in single
file. Eggs 2-3 times as long as body width. Neither spermatheca nor spermagonium
observed. Posterior uterine branch collapsed, 2-3 times as long as body
width. Phasmids terminal, best seen from a dorsal or ventral view. Males
not observed in Great Plains collections.
Habitat: Widely distributed throughout the region in both virgin
and cultivated soils.
(Description- Thorne & Malek, 1968)
DNA Sequences Obtained
