The genus Discolaimus in southern Africa. 2. Discolaimus constrictus sp. n. and D. monoplanus Heyns, 1963 (Nematoda: Dorylaimida)

Abstract

Discolaimus constrictus sp.n. is differentiated from D. mucurubanus Loof, 1964, the only other species in the genus in which the basal bulb is set off by a constriction, by its larger size, relatively shorter oesophagus, relatively shorter tail and more posteriorly situated vulva. In general appearance it more closely resembles D. affinis Loof, 1964, D. similis Thorne, 1939 and D. silvicolus Sauer & Annels, 1985. A large population of D. monoplanus Heyns, 1963 is described from Namibia. The remarkable similarity between D. monoplanus, D. texanus Cobb, 1913 and D. brevis Siddiqi, 1964 is pointed out, and the biometrics of all recorded populations of these three species are tabulated and briefly discussed.