Comparative Studies On Behavioral And Physiological Responses Between Apis Cerana Cerana And Apis Mellifera L. Exposed To Neonicotinoids

Neonicotinoid insecticides are currently the world’s most widely used of pesticides,it was used to not only pests,which do harm to crops in prevention and control,but also not belong to the target such as pollinated insects.As China is a agricultural country,honeybees play a vital role as a model organism in pollinated insects.In this study,the effects of neonicotinoid insecticides(imidacloprid and clothianidin)on the behavior,immune genes expression and detoxication enzymes specific activitiy of the Apis cerana cerana and Apis mellifera L.were studied.And assess the harm to the Apis cerana cerana and the Apis mellifera L.,to further explore the two species of honeybee immune mechanism and detoxification mechanism differences.In this study,the acute lethal toxicity of neonicotinoid insecticides to Apis cerana cerana by measuring imidacloprid and colthianidin on oral was firstly evaluated.Apis mellifera oral LD50 is 8.6 ng/bee for 24 h,Apis cerana cerana is 1.9 ng/bee by imidacloprid,and Apis mellifera oral LD50 is 2.0 ng/bee,Apis cerana cerana is 0.6 ng/bee by clothianidin.Apis cerana cerana are more sensitive to neonicotinoid insecticides than Apis mellifera.The effect of insecticides on learning and memory performance of honeybees was analyzed by sucrose behavioral reaction experiment.The experimental result showed that neonicotinoid insecticides have a greater impact on the learning and memory performance of Apis cerana cerana.By the experiment of learning performance,Apis cerana cerana treated by imidacloprid had an increasing PER begin for the fourth time,but this trend was not observed by Apis mellifera L.In this study,the expression of immune genes such as antimicrobial peptides in honeybees was measured.The results showed that neonicotinoid insecticides could up-regulate the expression of related genes,but the uptrend was different in two bee species.Apis cerana cerana treated by imidacloprid after 2 h,the highest expression of Eater was observed,however the treatment Apis mellifera L.was observed after 24 h.Defensin were inhibited in the Apis cerana cerana were treated,conversely in the Apis mellifera L.The specific activity of detoxification enzyme in different tissues of bees were statistically analyzed by honeybees which treated by neonicotinoid insecticides.The results showed that there was no significant difference in Apis mellifera and Apis cerana cerana,but neonicotinoid insecticides could cause specific activity increasing of polyphenol oxidase,carboxylesterase and glutathione-s-transferase While inhibiting the specific activity of acetylcholinesterase in honeybees brain,indicating that detoxification enzyme is also involved in the bee neonicotinoid insecticides defense mechanism,and neonicotinoid insecticides as a neurotoxic participated in the honeybee brain signal transmission.