Sublethal effects of pesticide combinations on Apis mellifera (Hymenoptera: Apidae)

Honey bee (Apis mellifera L.) populations worldwide have experienced a large decline over the past several years. Colony Collapse Disorder (CCD) has been acknowledged as the primary cause for the honey bee decline in the US; however, no specific cause of CCD has been identified. Pesticides are a major concern due to their widespread distribution within the hive. To date, our lab has found 118 different pesticides and pesticide metabolites in the hive, including insecticides, fungicides, herbicides, and insect growth regulators. Honey bees are readily exposed to numerous pesticides in their pollen food as larvae and this may cause both neural and hormonal changes that may alter development. Honey bee 1st instar larvae were collected from frames in the colony and reared in vitro. Their standard diet was composed of a royal jelly, carbohydrate, and yeast. The four most abundant pesticides in pollen were tested in the ratios in which they were found and the developmental and behavioral effects on larvae and adult bees were evaluated.