UNRAVELING IMPACTS ON HONEY BEE HEALTH OF AGRICULTURAL AND IN-HIVE PESTICIDES

Honey bees, Apis mellifera L., as a sentinel non-target species, are highly-susceptible to crop protection chemicals and serve as an excellent bioindicator of environmental quality. Bee disappearances threaten the production of nuts, berries, fruits, and vegetables. We will focus on the relevant ecotoxicology of honey bees with regard to their recent die-off referred to as Colony Collapse Disorder and to the declining health of honey bees in general. Honey bees are exposed to an average of five or more different pesticides in the pollen they collect and to high levels of acaricides in comb wax of their hives. This represents a new high level for pesticide residues in pollen collected by bees and is reflective of materials used in current agricultural practices. We propose to examine the toxicological and behavioral consequences of acute and sublethal pesticide exposures to honey bees from both dietary and in-hive encounters. We will use our data on pollen and comb wax levels to select relevant doses of the commonly encountered neonicotinoid, organophosphate, carbamate and pyrethroid insecticides used on major crops and in-hive as acaricides. We will cooperate with two current projects to provide pesticide residue quantification to further correlate the possible causal role of pesticides in Colony Collapse Disorder. We will determine if pesticides are involved in compromising the honey bee immune system, thereby increasing susceptibility to diseases. We will also determine if combinations of pesticides, herbicides, fungicides, and common formulation surfactants provide synergism for the most commonly encountered pesticides, and if these result in lower lethal and sublethal levels of toxicity to bees than currently predicted from pesticide labels. We will further determine if some of these sublethal effects modify associative learning in bees, and if they are detected by or modify the normal functioning of the contact chemosensory cells of bees and their resultant behaviors. Focusing on major pesticide and adjuvant exposures will unravel novel directions for maintaining honey bee health, and permit new avenues to safe, selective pesticides for in-hive mite and alternative pest control.