Steinernema loci sp. n. and Steinernema thanhi sp. n. (Rhabditida: Steinernematidae) from Vietnam

Two new species of Steinernema (Rhabditida), Steinernema loci sp. n. and S. thanhi sp. n., were isolated from beach soil in Thanhhoa and Hatinh provinces in the northern part of Vietnam. A combination of morphological, morphometric and rDNA-RFLP features indicated the distinctness of both species from other Steinernema spp. Diagnostic characters of Steinernema loci sp. n. include: total body length (896-1072 μm), distance from anterior end to excretory pore (EP = 71-86 μm), tail length (66-83 μm), lateral field in mid-body with eight ridges (nine distinct lines) and rounded, broad and smooth anterior end of the third stage infective juvenile; first generation males were characterised by body width, spicule length and the ratio spicule length : anal body width (SW). Diagnostic characters of Steinernema thanhi sp. n. third stage infective juveniles include: total body length (720-960 μm), EP (68-84 μm), tail length (52-72 μm), lateral field in mid-body with eight ridges (nine distinct lines) and rounded, broad and smooth anterior end. Spicule length, ratio SW and arrangement of genital papillae characterised the first generation males.