Studies On The Influencing Factors Of Molting And Bioinformatics Analysis Of Diapause Related Genes In Neoseiulus Barkeri

Neosuiulus barkeri is a natural enemies,which is widely used for biological control of agricultural pests and mites currently.The population stability in large-scale feeding and long-distance transportation has always been one of the factors affecting its utilization efficiency.Therefore,it is particularly important to study a feeding method with long shelf life and high survival rate.In this study,we analyzed the sequence and expression patterns of diapause-related genes such as EcR and Met by investigating the effects of temperature,number of food on the molting process to laid a foundation for further exploring the relationship between multiple hormone receptors and reproductive diapause.The main results are as follows:(1)The effect of temperature on the molting of N.barkeri showed that four times of molting were carried out in the whole generation at different experimental temperatures,and the times of molting were not changed by temperature.Temperature was negatively correlated with development duration and the development duration prolonged with the decrease of temperature.It took 8.42 days for the eggs to hatch and develop into adult mites at 25 ?,and 18.57 days at 18?.(2)The results of dietary and food density on molting showed that:food density had no significant effect on the molting process except its predation ability,while 20%sucrose did not make the N.barkeri successfully molt until the adult mites completed the whole development period after entering the nymph stage.(3)Bioinformatics analysis of EcR?Met and other genes of N.barkeri showed that the highest similarity was found with the aa sequence of Typhlodromus occidentalism and compared with the aa sequence of other species,EcR had the characteristics of nuclear receptor superfamily.There were LBD domains in some sequences,and Met also had PAS domains and HLH domains of bHLH-PAS transcription factor family.Quantitative fluorescence analysis of N.barkeri and female adult mites of reproductive diapause at different developmental stages revealed that that besides the significant expression of FoxO in diapause female adult mites,Met had the highest expression in protonymph stage,while EcR,E75 and Ftz-f1 had the highest expression in larva stage,the expression level was the lowest in reproductive diapause.The results showed that temperature was one of the factors affecting the molt of N.barkeri,and the number of molting times remained unchanged with the decrease of temperature,but the total immature period prolonged.The expression of EcR and Met in reproductive diapause female adult mites was the lowest.It has laid a foundation for further research on the hormone regulation of reproductive diapause of N.barkeri,by RNAi.