Laboratory and field evaluation of entomopathogenic nematodes for control of Agriotes obscurus (L.) (Coleoptera: Elateridae)

The susceptibility of the dusky wireworm, Agriotes obscurus (L.) (Coleoptera: Elateridae), to different species and strains of entomopathogenic nematodes was tested in a virulence assay in the laboratory. Larvae were exposed to different nematode doses of 50 and 100IJs/cm(2). At a dose of 50IJs/cm(2), only a commercial strain Heterorhabditis bacteriophora Poinar and the native strain Steinernema carpocapsae (Weiser) B14 caused increased mortality compared with the control (11.1% and 13.3% mortality, respectively). At the higher dose tested, all strains (except Steinernema sp. D122) were virulent to A.obscurus larvae. Steinernema carpocapsae B14 caused higher mortality of wireworm (75.6%) and was used for the assay conducted in cages, with a dose of 100IJs/cm(2), in field conditions. The results showed that S.carpocapsae B14 controlled 48.3% of A.obscurus larvae, demonstrating that some entomopathogenic nematodes have the potential to control larvae of A.obscurus. However, further work is needed to improve their efficacy.