The role of honey hydrogen peroxide (H2O2) as a natural defense mechanism against small hive beetle (Aethina tumida) infestations

Small hive beetle (SHB, Aethina tumida) is a devastating pest of honeybee (Apis mellifera) colonies. While various chemical treatments and traps have been employed to control SHB population, it is plausible that honeybees produce natural chemical defenses in their honey. We tested the hypothesis that hydrogen peroxide (H₂0₂) – which is added to nectar via the enzyme glucose oxidase – acts as a stress defense against SHB. Comparative field studies in apiaries from across the southeastern US revealed that honey H₂0₂ concentrations were highest in colonies infested by SHB. Controlled laboratory experiments indicated that adult SHB survival decreased up to 63% at honey H₂0₂ concentrations of 400-1600 µg/ml, an effect that was reversed in controls containing the antioxidant catalase. Moreover, the addition of catalase to control honey samples enhanced SHB survival and reproduction. These data are consistent with the hypothesis that H₂0₂ my act as a natural defense mechanism or stress response to SHB. Thus, the molecular regulation of glucose oxidase could be connected to honeybee SHB resistance. Additional experiments are in progress including controlled, time-series field measurements of honey H₂0₂ throughout induced SHB infestation..