[Severianoia blapticola sp. n. (Oxyurida: Thelastomatidae): a new nematode species from blaberid cockroaches].

A new nematode species of the genus Severianoia (Schwenk, 1926) Travassos, 1929, S. blapticola sp. n., is described from the hind gut of cockroach Blaptica dubia (Serville, 1839) from laboratory culture. The main morphological feature of S. blapticola sp. n. is the presence of columnar cuticular structures of different height on the ventral side of male posterior end. In the gut of B. dubia these nematodes coexist with another thelastomatid genus, Cranifera Kloss, 1960 [C. cranifera (Chitwood, 1932) Kloss, 1960]. Males of C. cranifera are characterized by the presence of cloacal projection and columnar structures on both dorsal and ventral sides of male posterior end.