Steinernema leizhouense sp n. (Nematoda: Steinernematidae), a new entomopathogenic nematode from southern China

A new species of entomopathogenic nematode, Steinernema leizhouense, is described. It was recovered from a soil sample collected from Leizhou district, Tangjia town in the western part of Guangdong province, the People's Republic of China during a survey for entomopathogenic nematodes in 2001. The nematode has characteristics of both S. glaseri and S. feltiae groups but is closer to the S. glaseri group. Steinernema leizhouense is characterized by body length 983 (900-1050) mu m, large infective juvenile body diameter 38 (35-43) mu m, distance from anterior end tc. nerve ring 101 (95-108) mu m; oesophagus length 133 (125-143) mu m and a = 28 (23-38). Lateral field pattern variable, the formula for the arrangement of ridges from head to tail is 2, 6, 8, 4, 2. The new species can be recognized further by male spicule length averaging 82 (75-93) mu m, spicule head longer than wide, spicule blade thin, velum narrow or absent, and by SW% = 210, GS% = 50. The female of the new species is characterized by nipple-shaped tail terminus. The closest species are S. loci and S. aciari. The new species can be differentiated from related species by cross-breeding tests and by sequences of both a partial 28S rDNA and the internal transcribed spacer regions of rDNA.