| Bees are one of nature’s primary pollinators to help pollinate plants,it plays an important role in protecting the ecosystem.In recent years,throughout the world happened Colony Collapse Disorder(CCD),resulting in a large number of the number of bee colonies disappearing phenomenon,used in the production of agricultural chemicals,is considered one of the causes of this phenomenon induced.In this paper,based on the early detection results of pesticide residues in bee bread and other samples from honey source production areas in China,four chemical pesticides with high detection rate and high concentration of beta-cypermethrin,chlorbenzuron,chlorothalonil and pendimethalin were selected.Conducted chronic toxicity experiments on larvae of Apis mellifera ligustica and Apis cerana cerana.And selected high-efficiency beta-cypermethrin and chlorbenzuron with large differences in toxicity to the two larvae.We studied its effect on two kinds of bee larvae four major activities,two kinds of hormone titer and sensitivity difference of sense of smell.Below are key research findings:1.Chronic toxicity of four pesticides to the larvae of A.m.ligustica and A.c.ceranaThe average and maximum detection concentrations of beta-cypermethrin,chlorbenzuron,chlorothalonil,and pend imethalin in bee food samples were selected,and the chronic toxicity of four chemical pesticides to A.m.ligustica and A.c.cerana larvae was determined by feeding methods.The results showed that beta-cypermethrin and chlorbenzuron were more chronically toxic to the larvae of A.m.ligustica and A.c.cerana,while there were differences between the larvae of A.m.ligustica and A.c.cerana,and chlorothalonil and pend imethalin were chronic to the larvae of A.m.ligustica and A.c.cerana less toxic.Among them,under 1225.3 ng/g beta-cypermethrin treatment,the mortality,pupation rate and eclosion rate of the A.c.cerana larvae were 1.38 times,0.74 times and 0.67 times of the A.m.ligustica respectively;under the treatment of 1021.4 ng/g chlorbenzuron.The mortality,pupation rate and emergence rate of bee larvae were 1.14 times,0.91 times and 0.54 times of A.c.cerana larvae.2.Effects of beta-cypermethrin and chlorbenzuron on the activities of four enzymes in the larvae of A.m.ligustica and A.c.ceranaTwo chemical pesticides,beta-cypermethrin and chlorbenzuron,were selected to study their effects on acetylcholinesterase(AChE),glutathione s-transferases(GST),super the effects of the four enzyme activities of superoxide dismutase(SOD)and polyphenol oxidase(PPO).The results showed that,under the treatment of beta-cypermethrin,the AChE and PPO enzyme activities in the larvae of A.m.ligustica and A.c.cerana were inhibited,while the GST activities in A.m.ligustica and A.c.cerana were induced;the SOD activities in A.m.ligustica and A.c.cerana induced high doses inhibition,the SOD activity of A.m.ligustica and A.c.cerana larvae reached the maximum under low dose(323.5 ng/g)treatment,which were 3.6195 U/mgprot and 4.4692 U/mgprot,respectively.Under the treatment of chlordiazuron,the activities of AChE,GST and SOD in the larvae of A.m.ligustica and A.c.cerana were all induced;however,the activity of PPO was inhibited.Among them,under the treatment of 1021.4 ng/g chlordiazuron,the PPO activity of A.m.ligustica larvae was 0.49 times that of the control group,and the PPO activity of medium bee larvae was 0.40 times of the control group.3.Effects of beta-cypermethrin and chlorbenzuron on the titers of hormones in the larvae of A.m.ligustica and A.c.ceranaThe larvae treated with beta-cypermethrin and chlorbenzuron were tested by UPLC-MS/MS technology for the titer levels of larval preservation hormones of A.m.ligustica and A.c.cerana respectively.The results showed that under the treatment of 1225.3 ng/g beta-cypermethrin,the ecdysone of A.m.ligustica was 0.48 times of the control,and the ecdysone of A.c.cerana was 0.37 times of the control;The bee ecdysone was 0.37 times that of the control.Under the treatment of 62.6 ng/g chlorbenzuron,the titer of juvenile hormone and ecdysone of A.m.ligustica were 1.40 times and 0.46 times of the control,and the titer of juvenile hormone and ecdysone of A.c.cerana were 1.30 and 0.32 times that of the control.4.The effect of beta-cypermethrin and chlorbenzuron on the beak extension of worker bees of A.m.ligustica and A.c.ceranaTargeting adult worker bees bred in larval stage exposed to beta-cypermethrin and chlorbenzuron,carried out extended beak reaction experiments.The results showed that when 0.1%sucrose water was used to easily stimulate the antennae of the worker bees of the two Bee species,the response to beak extension was not significant.However,when 1%sucrose solution worker bees stimulation kinds of bees,A.m.ligustica found more than the number of projecting beak reaction A.c.cerana.When exposed to beta-cypermethrin,the A.m.ligustica beak-stretching response was 1.85 times that of the A.c.cerana,while exposed to the chlorbenzuron environment,the A.m.ligustica was 1.22.times that of the A.c.cerana. |
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