The effect of different pesticides on reproduction of entomopathogenic nematodes

Abstract

Entomopathogenic nematodes (EPNs) in the families Steinernematidae and Heterorhabditidae are generally considered beneficial nematodes. These beneficial nematodes can serve in integrated pest management (IPM) in agro-ecosystems. The effect of chemical insecticides (11 different pesticides) on Steinernema sp. (EBN-1e), and Heterorhabditis bacteriophora (EBN-10k) was determined under laboratory conditions. Generally, EBN-1e Steinernema strain was more tolerant to different tested insecticides than Heterorhabditis strain. The survival of IJs was more than 90% after treatement with Captan, Methomyl, Mancozeb, Benomyl, Trimiltox forte and Diafenthiuron, for EBN-1e nematode strain, while Chlorfluazuron decreased its survival to less than 5%. In contrast, the survival of Heterorahbditis strain was less than the Steinernema strain. There were significant differences in reproduction rates between EBN-1e and EBN-10k exposed to different chemical insecticides. The EBN-1e strain had higher reproduction rate than EBN-10k in all treatments. In general, there was significant difference in reproductive rates between the species concentrations (500 IJs and 1000 IJs) exposed to different chemicals or between exposure times (48 h. and 96 h.)