The consumption and survival rate of Lilioceris cheni (Coleoptera: Chrysomelidae) on air potato leaves exposed to Cordyceps javanica (Hypocreales: Cordycipitaceae)

Abstract

PFR-97 20% WDG (PFR-97) is a broad-spectrum entomopathogenic fungal biopesticide that contains the active ingredient Cordyceps javanica (Frieder. & Bally) Kepler, B. Shrestha & Spatafora (Hypocreales: Cordy- cipitaceae). This biopesticide is labelled for controlling aphids, psyllids, spider mites, thrips, and whiteflies in various crops, but also can infect certain chrysomelid species. Pest control activities applying PFR-97 in 1 agroecosystem may inadvertently drift and affect biological control agents purposefully released in another ecosystem. Therefore, our goal was to determine if PFR-97 was compatible when applied near Lilioceris cheni Gressitt and Kimoto (Coleoptera: Chrysomelidae), a chrysomelid biological control agent for the invasive air potato. The consumption and survival rates of adult beetles after exposure to PFR-97 were investigated via leaf bioassays. Thirty L. cheni adults were provisioned individually with a Dioscorea bulbifera L. (Dioscoreaceae) leaf sprayed with either a C. javanica suspension at the concentration of 106, 105, 103, or 102 blas- tospores per mL-1 or sterile distilled water (control) for 72 h. Untreated leaves were provided every 3 d for an additional 18 d and leaf consump- tion was determined. Results showed the survival and leaf consumption of the L. cheni adults did not differ among treatments and control. Over- all, our study demonstrated that any inadvertent exposure of L. cheni adults to C. javanica via spray drift is unlikely to impact the performance of the adult biological control agents.