Meeting Abstract
Currently, serious population declines have been associated with, among other causes (beekeeping practices, parasites, and viruses), Colony Collapse Disorder (CCD). We studied the sublethal effects of the neonicotinoid pesticide Thiacloprid, which is mainly used on green apples, cherries, and pears. Thiacloprid acts as an agonist for nicotine on insects, constituently binding to sodium channels. To understand the sublethal effects of Thiacloprid in A. mellifera, we examined sucrose sensitivity to assess effects on central nervous system processing, and motor function to evaluate peripheral nervous system function. We studied sublethal doses that were dilutions (1/5, 1/10, 1/50, 1/100, 1/500, 1/1000) of the LD50 in 1.5 M sucrose. Bees were fed 10uL of a Thiacloprid treatment in 1.5 M sucrose. Motor response was assessed 4h after feeding by testing the proboscis extension reflex (PER), along with leg, abdomen, and wing movement. Sucrose sensitivity was measured 4h after feeding by a positive PER to six (1%, 3%, 10%, 20%, 35%, 50%) sucrose solutions. At 1/5 of the LD50, Thiacloprid reduced motor coordination compared to the controls. Similarly, bees in the 1/5 LD50 treatment displayed reduced sucrose sensitivity. Our results indicate that the performance of crucial components in foraging controlled by the CNS and PNS, are reduced by sublethal doses of Thiacloprid. This provides further evidence that concentrations used in agriculture may produce harmful effects in honey bees that could contribute to CCD.
