Aphelenchoides confusus
Thorne & Malek, 1968
0.6 mm; a = 30; b = 8.6 (bulb); c = 18; V
= 71
Body cylindroid,
tapering gradually near extremities. Cuticle finely striated. Lateral fields
marked by 4 very fine lines, about 1/8 body width. Lip region set off by
constriction. Spear without knobs, 12u long, its muscles attached to refractive
band at base of cephalic framework. Corpus of esophagus set off from bulb
by narrow constriction. Bulb
filling neck cavity with massive valvular apparatus. Isthmus a slender
hyaline tube shorter than neck width, set off from bulb by constriction.
Nerve ring 1/2 body width behind bulb. Excretory pore opposite ring. Hemizonid
more than a body width posterior to excretory pore. Basal esophageal lobes
extending dorsally 5 or 6 body widths. Vulva
with protuberant labia. Vagina extending slightly forward. Uterus with
massive spheroid spermatheca almost filling body cavity, packed with sperms.
Ovary outstretched, sometimes extending to median bulb. Eggs twice as long
as body width. Posterior uterine branch collapsed, extending 1/3 to 1/2
distance back to anus. Tail
conoid
to blunt, rounded terminus, with phasmids almost terminal. Male not collected
but sperms present in spermatheca.
Aphelenchoides confusus is distinctive because of offset lip
region, knobless spear, posteriorly located hemizonid, massive spermatheca
and elongate-conoid tail with phasmids near terminus. Probably most closely
related to A. limberi Steiner, 1936 which has small spear knobs
and cylindroid tail.
Holotype female and 4 other specimens as indexed under Aphelenchoides
3.
Habitat: Wheat field near Colorado-Nebraska state line on U.S. Highway
6, Downer, Minnesota, and Fairmont, North Dakota.
Under lower powers of the microscope this species resembles a long-tailed
Aphelenchus,
hence the name confusus.
(Description- Thorne and Malek, 1968)
