Efficacy of entomopathogenic nematodes on Colorado potato beetle (Leptinotarsa decemlineata)

Abstract: Colorado potato beetle Leptinotarsa decemlineata is a serious pests of potatoes known to quickly develop resistance to insecticides. Therefore, we tested the effect of various species and strains of entomopathogenic nematodes on CPB adults in Petri dish experiments, and the most effective nematodes were applied in pots with potato plants and in the field and their effect on the number of emerging adults was evaluated. Furthermore, we tested the antifeedant effect of the metabolites of bacterial symbionts of entomopathogenic nematodes on CPB adults. In Petri dish experiments, both the nematode invasion and pathogenicity were variable, with several strains causing 100 % mortality. In the antifeedant assay, some supernatants effectively decreased feeding by CPB adults. Our study shows the necessity of thorough bioassays to select the most effective nematode strains.