Effects of coumaphos on queen rearing in the honey bee, Apis mellifera

Young honey bee larvae were transferred into the queen cups containing known concentrations (0 to 1000 mg/kg) of the organophosphate pesticide coumaphos. These larvae were placed in queenless colonies and examined ten days later to determine the rate of rejection or acceptance as indicated by a mature sealed queen cell. All queens failed to develop at 1000 mg/kg, and greater than 50% of the queen cells were rejected at the 100 mg/kg concentration. Additionally, queens that survived exposure to 100 mg/kg coumaphos weighed significantly less than control queens. The implications of exposure of developing queens to sublethal amounts of pesticides are discussed.