Type Habitat and Locality
Soil around roots of grapevine (Vitis sp.), Wadi Dhulail, Jordan.
Collected by the author in August, 1981 and January, 1982. Holotype female and five paratype females at Rothamsted Experimental Station, Harpenden, Hertfordshire, England. Five paratype females at Commonwealth Institute of Parasitology, females at Muséum national díHistoire naturelle, Laboratoire des Vers, Paris, France.
Pratylenchus jordanensis n. sp. is differentiated from previously described Pratylenchus species, except P. agilis Thorne & Malek, 1968, P. hexincisus Taylor & Jenkins, 1957, P. crassi Das & Sultana, 1979 and P. scribneri Steiner, 1943, by the absence of males, empty Spermatheca of the female, cephalic region with two annules and slightly offset from the body, short stylet (< 18 um), V coefficient less than 80, undifferentiated post-vulval sac (16.2 um in length) and smooth tail terminus. It differs from the above-mentioned four species in the indentation of the tail terminus. It also differs from P. agilis (as described by Thorne & Malek, 1968) in its shorter stylet (14.6 vs. 17.8 um) and apparently slower movements, and from P. hexincisus (as described by Taylor & Jenkins, 1957 and Thorne & Malek, 1968) in having four incisures on the lateral field, often with additional oblique striae in the central band at mid-body (six incisures, some of which are irregularly broken at mid-body, in P. hexincisus). P. jordanensis n. sp. is also distinguished from P. crassi by the shorter stylet (14.6 vs. 17-18 um), the greater distance between the dorsal oesophageal gland orifice and stylet base (3.4 vs. 2.1 um) and the greater number of tail annules (21 vs. 12-15). (According to Das and Sultana, 1979, P. crassi has a large oval spermatheca filled with spermatozoa; however, this structure was not illustrated for this species and males were not found). P. jordanensis n. sp. is also differentiated from P. scribneri (as described by Sher and Allen, 1953, Thorne and Malek, 1968 and Roman and Hirschmann, 1969) by the slightly more conoid tail with a slightly narrower terminus, the greater distance between the dorsal oesophageal gland orifice and stylet base (3.4 vs. 2.15 um, the latter according to Roman and Hirschmann, 1969) and the inner incisures fused distally on the tail (apparently not fusing on the tail in P. scribneri). Eight specimens of P. scribneri from the USA (California), originally identified by J. Roman, were made available to the author by courtesy of D.J. Hooper. These differed from P. jordanensis n. sp. in the broader tail terminus which is not indented, the lower cí coefficient (2.1 (2.0-2.3) vs. 2.6 (2.1-3.0); n = 6) and the absence of intestinal fasciculi (1). The lateral fields were difficult to discern on the caudal region of these specimens of P. scribneri, so that the apparent difference in lateral field morphology between these species and P. jordanensis n. sp. (inner incisures fusing in this region in P. jordanensis but not P. scribneri) could not be confirmed. Moreover, the difference in the position of the dorsal oesophageal gland orifice between the two species is perhaps too small to be of diagnostic value.
(1) The intestinal fascuculi of P. jordanensis do not constitute a unique character within the genus Pratylenchus, I have observed similar structures in P. goodeyi Sher & Allen, 1953 from the Canary Islands.