Species-specific enzyme phenotypes of Steinernema carpocapsae, S. glaseri and S. thermophilum (Nematoda: Steinernematidae)

Esterase, catalase and superoxide dismutase isozymic profiles of infective juveniles of Steinernema thermophilum(IARI-EPN1), S. carpocapsae (IARI-EPN-am1), and S. glaseri (IARI-EPN-up2) were resolved on polyacrylamide mini slab-gel electrophoresis. Remarkable differences among the species were evident as each species exhibited a unique banding pattern based on their Rf values. Isozymic profiles of esterase exhibited two species-specific bands in S. thermophilum, S. carpocapsae and S. glaseri, located at Rf 0.48 and 0.53, 0.52 and 0.65, and 0.69 and 0.87, respectively. Isozymic profiles of catalase revealed species-specific four isozymic bands in S. thermophilum, one in S. carpocapsae and two in S. glaseri. Superoxide dismutase isozymic profiles also revealed speciesspecific patterns for S. thermophilum (three bands), S. carpocapsae (three bands) and S. glaseri (one marked band). The combination of esterase, catalase and superoxide dismutase isozymic profiles from infective juveniles can be useful for preliminary differentiation of three indigenous species of Steinernema.