Comparison of Some Biological Characterizations of the Entomopathogenic Nematodes, Steinernema weiseri and S. feltiae (Rhabditida: Steinernematidae), Isolated in Turkey

Abstract

The infectivity of S. weiseri and S. feltiae was evaluated by releasing Galleria mellonella larvae to sand containing nematodes at various densities (10, 25, 50, 100, 150 and 300 dauer juveniles or DJs). Insect mortality was evaluated after 48 h. S. weiseri was more infective than S. feltiae at all densities. At 10 DJs, larval mortality was not observed in sand containing S. feltiae, but larval mortality reached 22.5% in sand containing S. weiseri. The LD 50 values of S. weiseri and S. feltiae were 25.68 and 80.70 DJs, respectively. The reproductive potential of both nematodes was investigated under varying nematode densities (10, 50 and 100 DJs per G. mellonella larva) and temperatures (10, 15 and 20 degrees C). S. weiseri was generally more productive than S. feltiae. Differences in the level of reproduction between S. weiseri at 50 DJs and S. feltiae at 100 DJs were not significant at 15 and 20 degrees C. The rate of reproduction increased as the temperature increased.