Susceptibility of a native and an exotic lady beetle (Coleoptera: Coccinellidae) to Beauveria bassiana.
The exotic multicolored Asian lady beetle, Harmonia axyridis, became established and recently spread across much of North America and southern Canada. In a habitat now used by both the invading H. axyridis and a native lady beetle, Olla v-nigrum, we discovered that the native lady beetle was commonly infected by Beauveria bassiana; whereas, the exotic H. axyridis, was not. Laboratory assays revealed that B. bassiana isolates collected from naturally infected O. v-nigrum were pathogenic to adult O. v-nigrum but not to adult H. axyridis. In contrast, the GHA strain of B. bassiana was not significantly pathogenic to O. v-nigrum nor H. axyridis. Late-season field collections revealed significantly higher B. bassiana infection of O. v-nigrum than H. axyridis. Our results lead us to hypothesize that low susceptibility of H. axyridis to B. bassiana (found to infect O. v-nigrum) may provide an intraguild advantage to H. axyridis over O. v-nigrum; this may also occur with other species of native lady beetles and other endemic entomopathogens in different habitats and regions.
Cottrell
Ted E
TE
United States Department of Agriculture, Agricultural Research Service, Southeastern Fruit and Tree Nut Research Laboratory, 21 Dunbar Road, Byron, GA 31008, USA. tcottrell@saa.ars.usda.gov
Shapiro-Ilan
David I
DI
D000818:Animals; D001517:Coleoptera / Q000469:parasitology*; D004198:Disease Susceptibility / Q000469:parasitology; D004777:Environment; D006999:Hypocreales / Q000472:pathogenicity* / Q000502:physiology; D009181:Mycoses / Q000453:epidemiology*; D010572:Pest Control, Biological