Mid-Infrared Spectroscopy Study of Effects of Neonicotinoids on Forager Honey Bee (Apis mellifera) Fat Bodies and Their Connection to Colony Collapse Disorder

Abstract

This study investigated the negative effects of neonicotinoid pesticides on honey bees in environment surrounding areas of pesticide use. The aim of the experiment is to identify possible contributors to the sudden decrease in honey bee population over the past 60 years, a phenomenon known as Colony Collapse Disorder. Analysis was performed on three sets of bees: the control group which was not in contact with pesticides, the infected dead group which was a set of bees suspected to have died due to neonicotinoids, and the infected alive group which was suspected to be under the influence of neonicotinoids. After dissecting the bee samples and extracting their fat bodies, the chemical composition and protein structures of the samples were analyzed using Mid-Infrared Beamline at the Canadian Light Source. Results from the spectra of bee samples exposed to neonicotinoids demonstrated possible residual pesticide chemicals within fat bodies. Several spectral peaks were also correlated with a possible change in protein secondary structures from primarily {beta}-sheet to -helix within fat bodies of neonicotinoid-affected bees. It is likely that the pesticides caused the growth of additional -helical structures, which is consistent with consequences of the inhibition of nicotinic acetylcholine receptors (nAChRs) a current pathway of harm of Colony Collapse Disorder as identified in past literature.