D3037: Beauveria bassiana effects on wireworm survival and behaviour

Beauveria bassiana is a fungal entomopathogen which affects and kills a variety of arthropod hosts worldwide. The use of B. bassiana as a biological control agent in wireworms is of interest due to limited effective control options. Wireworms are the larvae of Elaterid beetles and are major subterraneous pests of a variety of crops worldwide. They are especially a concern for potatoes, where they will feed and tunnel into the tubers, making the potatoes unmarketable. Our B. bassiana strain of interest has been found to cause a reduction in feeding damage in potatoes by wireworms; however, it does not cause short-term wireworm mortality. Our aim is to investigate the mechanism by which B. bassiana protects potatoes from wireworm damage. We conducted survival assays, two-choice experiments, and behavioural bioassays using primarily Agriotes lineatus, and also comparing two other wireworm species Agriotes sputator and Hadromorphus glaucus. Results showed that there were no significant differences in survival between treated and untreated wireworms, but there were species differences. Wireworms were repelled by B. bassiana as granules, free spores in soil, and by daughter tubers of inoculated potato plants. A small reduction in the number of time points spent feeding was observed in B. bassiana-inoculated wireworms. This research will provide insight into the effects of an entomopathogen on a pest insect despite not causing mortality.