Managing Colorado potato beetle and corn wireworm with indigenous entomopathogenic nematodes in potato

Colorado potato beetle (CPB), Leptinotarsa decemlineata (Say), and corn wireworm, Melanotus communis Gyllenhal, are two serious pests of potato. In this study, we explore the use of native strains of three entomopathogenic nematodes (EPN), Steinernema carpocapsae, S. feltiae, and Heterorhabditis bacteriophora, as biocontrol agents against both pests at their soil-dwelling life stages. Specifically, we evaluated the long-term establishment of those EPNs in the soil. As the three nematode species have different foraging behavior in the soil, whether an ambusher, a cruiser, or both, the other objective of this study is to identify the best combination of native nematode species for managing CPB and corn wireworm in potatoes. Current results indicated that the EPN combination of S. feltiae and H. bacteriophora reduced corn wireworm damage in marketable tubers by 8% when compared to the nontreated control. However, none of the EPN combinations significantly reduced CPB adult emergence in the field. Among the three EPN species, late instar CPB larvae were most susceptible to H. bacteriophora based on a lab soil-based bioassay.