Abstract: Pest control became more efficient and safer due to the development of neonicotinoids in recent years.Conversely, the usage of neonicotinoid pesticide causes declination among many non-target insects, such as pollinators. Imidacloprid, a neonicotinoid insecticide, has been suspected inducing the colony collapse disorder (CCD) of honey bees by disordering the navigation system and/or disrupting their foraging behavior.Our previous studies showed that after feeding with sublethal imidacloprid during larval stage the density of synaptic units in adults’ mushroom body calyces would decrease, even the treatment concentration was as low as 10 ppb! This indicated that the decrease of olfactory learning ability is related to the abnormal neural connectivity, thus demonstrates the imidacloprid impairs the development of nervous system from the larval stage of honey bees. In this proposal our research project focuses on three parts: histological study on the
neural somata and synapses in the honey bee brain, electrophysiological measurement of visual and olfactory sensitivity, and behavioral monitoring in beehives, to reveal the sublethal effects of imidacloprid to honey bee’s nervous system and behavior. By immunocytochemistry methods, we aim to label the deeperparts of the brain, and using laser scanning confocal microscopy and two-photon pulse laser microscopy to visualize images. By electroretinogram (ERG) and electroantennogram (EAG) recording, we aim to reveal how the sensory sensitivities of visual and olfactory functions are affected by imidacloprid exposure in larval stage. By special design infra-red monitoring chamber adapted to beehive, we aim to reveal how the interactions among individuals are affected by imidacloprid exposure in larval stage. With understanding the sublethal effect on individual and colony, the experiment will shed light on neural toxicology of honey bee.