Attraction of Myzus persicae to volatiles emitted from the entomopathogenic fungus Beauveria bassiana

Insects exhibit a variety of behavioral responses to microbial volatile organic compounds (MVOCs). Previous studies have demonstrated MVOCs emitted from the entomopathogenic fungus Beauveria bassiana can act as repellents or attractants depending on the species of insect. Attracting insect hosts would be beneficial to B. bassiana since it requires direct contact for infection and has no other active mechanisms of dispersal. A series of experiments were conducted to assess host-pathogen interactions between Myzus persicae and B. bassiana. The specific objectives were to assess M. persicae behavioral responses to B. bassiana, and identify MVOCs emitted from B. bassiana. Time-course behavioral responses of apterous and alate M. persicae to B. bassiana mycelium and conidia were assessed using still-air and y-tube bioassays. Results from the still-air and y-tube bioassays revealed aphids were attracted to mycelium and conidia of B. bassiana. Mortality of M. persicae also increased following attraction to B. bassiana. MVOCs emitted by mycelium of B. bassiana were collected and analyzed using solid phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS). A variety of MVOCs were identified in emissions from the mycelium of B. bassiana, including alcohols, acids, amides, acetates and sesquiterpenes. Additional bioassays and electroantennography will be conducted to further characterize the volatile basis for attraction of M. persicae to B. bassiana. Enhancing the attraction of M. persicae to B. bassiana could improve the efficacy of this entomopathogenic fungus as part of microbial control tactics.