Description: Female: Body slightly arcuate
ventrally, tapering anteriorly from base of oesophagus to lip region and
posteriorly from vulva to tail. Transverse striations about 1.4um
apart at midbody. Lateral field with 4 incisures, occupying 1/3 of the
Lip region striated, truncate anteriorly, continuous with body contour. Stylet well developed, 7-8um long, with anterior tapering part 1/3 of its total length. Basal spear knobs rounded, measuring about 2um across. Orifice of dorsal oesophageal gland duct 3um from spear base. Median oesophageal bulb ovate, pre-equatorial in location (40-45%). Basal oesophageal bulb sac like, set off from the intestine. Cardia small about 2um in size. Excretory pore located in the region of anterior end of basal oesophageal bulb. Hemizonid at the level of excretory pore. Vulva a depressed transverse slit, located at 60-63% of the body. Vagina thick-walled, at right angles to body axis. Ovary monoprodelphic, post-vulval uterine sac half of the vulval-body-width long. Vulva-anus distance shorter than tail length. Tail ventrally arcuate, about 13 anal body-widths long, regularly tapering to a finely pointed terminus.
Male: Body slightly ventrally arcuate, 0.5-0.6 mm long. Body striae about 1.4um wide near midbody. Lateral field with 4 incisures; 1/3 as wide as corresponding body diameter. Spear 7-8um long. Orifice of dorsal oeophageal gland duct 3um behind spear base. Spicules ventrally curved 16um long. Gubernaculum simple, trough-shaped, 4-5um in length. Bursa adanal. Tail ventrally arcuate, 11 anal body-widths long, gradually tapering to a pointed terminus.
Type habitat and locality: Collected from soil around roots of orange in District Jalalabad, Afghanistan, by Mr. Sher Khan Prau, Lecturer, Higrahar University, Jalalabad.
Diagnosis and Relationship: Tylenchus sheri n. sp.
comes close to T. discrepans Andrassy, 1954 and Tylenchus butteus
Thorne and Malek, 1968 and T. cylindricollis Thorne and Malek, 1968.
It differs from T. discrepans in having longer body with relatively
narrow head with basal ring of cephalic framework, narrower body and shorter
post-uterine sac (L = 0.39-0.43 mm; head relatively broad and without basal
ring of cephalic framework; a = 27-33; post-uterine sac as long as vulval
body-width in T. discrepans). Males differ from those of
discrepans in having longer spicules and gubernaculum (Spicules and
gubernaculum 13-14um and 3um long respectively in T. discrepans).
It differs from T. butteus in having differently shaped head, smaller
spear, shorter neck, wider lateral field, longer post-uterine sac and longer
tail with differently shaped terminus (head broad; spear 12um long;
b = 4.5: lateral field about 1/5 body-width at midbody; post-uterine
sac less than half as long as vulval body-width; and, tail slightly less
than 9 anal body-widths long, ending in a finely rounded terminus in T.
butteus). It differs from T. cylindricollis
in the shape
of head, presence of basal ring of cephalic framework, more anteriorly
located vulva and longer and differently shaped tail (head broad; cephalic
framework and basal ring absent; vulva located at 68%; post-uterine sac
less than half the vulval body-width in length; c = 6; tail about
8 anal body-widths long and ending in abruptly conoid or rounded terminus
in T. cylindricollis). T. sheri also is similar to
T. mirus Husain et Khan, 1967 and T. cydontus
et Khan, 1967, but differs from the first in having truncate head,
longer body, shorter spear and anteriorly located median oesophageal bulb,
and from the second because of its longer body, truncate head, longer tail
and posteriorly located excretory pore.
(Description- Khan & Khan, 1978)