Effects Of Prey Types And Temperatures On The Development And Predation Ability Of Arma Chinensis Fallou

Arma chinensis Fallou,as an important predator,prefer to prey pests of Lepidoptera especially.It is a potential natural enemy of Ectropis griscens Warren,which is the important leaf-eating pest in tea plantations.However,except for the pupae of Antheraea pernyi Guerin-Meneville,the lower survival rate,longer development period,and lower fecundity of A.chinensis were observed when preys on other pests,which affected the control effect for this predator.In this study,we used the age-stage,two-sex life table,metabolomics and enzyme-linked immunosorbent assay（ELISA）to evaluate the feasibility of A.chinensis in controlling E.griscens by means of the nutritional composition of different types of prey(pupae of A.pernyi（Ap-P）pupae of E.griscens（Eg-P）,2^nd～5^thinstars of E.griscens（Eg-L2～5）and 3^rd instar of E.griscens（Eg-L3）)and the predation rate of natural enemies under different temperatures（22,26and 30℃）,which considering the evaluation content of the effectiveness of predatory natural enemies.Based on a sustainable concept,this study is aiming to analyze the long-term effective biocontrol of E.griscens in various tea-producing areas with A.chinensis,which provide a theorical reference for the practice of biocontrol for E.griscens.The main research results were listed as follows:1.Acroding to consume E.griscens of different stages,A.chinensis could develop from eggs to adults,but there were significant differences in development duration,survival rate,and fecundity of A.chinensis.The growth and development parameters of A.chinensis preyed on Eg-P were better than those preyed on Eg-L3 and Eg-L2～5.And the immature durition of A.chinensis preyed on Eg-L2～5 was longer,the survival rate,and fecundity were lower.The fecundity of A.chinensis preyed on Eg-L3was 0.Although the fecundity of A.chinensis preyed on Eg-P was slightly lower than those preyed on Ap-P,there was no significant difference.And the survival rate of A.chinensis preyed on Eg-P was higher,the APOP and the T was shorter,which result in the highest intrinsic rate of increase（r）,finite rate of increase（λ）,and the population growth potential.2.The metabolomics results showed that different development stages of E.griscens could regulated the contents of various nutrients（such as lipids,organic acids and derivatives,organic heterocyclic compounds,organic oxygen compounds,and polyketides et al.）,which were closely related to growth and development of A.chinensis,by changing the amino acid,carbohydrate,lipid,and other metabolism pathways.Thus lead to the changes of nutritional quality of prey.And Eg-P was similar to Ap-P in nutrient composition.3.The titers of 20E and JH of A.chinensis were different significantly at different treatments.Compared with preyed on Ap-P,the hormone titers of A.chinensis were higher or lower in when preyed on Eg-L2～5 and Eg-L3,which were not conducive to the development and reproduction of A.chinensis.The results of RDA analys is showed that the levels of metabolites such as organic acids and derivatives,organic oxygen compounds,steroids and their derivatives,flavonoids et al.as well as secondary substances in different prey types were s ignificantly correlated with the synthesis of 20E and JH in A.chinensis.4.The parameters of life table,population,and predation of A.chinensis preyed on 2^nd～5^thinstars of E.griscens had significant differences among different temperatures.However,at 26 and 30℃,A.chinensis had the highest survival rate and fecundity.The predation rate of the 5^th instar nymphs and adults of A.chinensis was the highest among different temperatures.The highest daily predation of A.chinensis occurred at 26℃at the nymph stage and adult stage,and the predation parameters of A.chinensis at 22℃were lower than those at 26 and 30℃,which indicated that 26 and 30℃were more suitable for the population growth and predation of A.chinensis.In conclusion,the generational development of A.chinensis could be completed by preying on E.griscens,and had the highest fecundity as well as population growth when preyed on pupae of E.griscens under laboratory conditions.It was more feasible for A.chinensis to colonize by preying on E.griscens.Therefore,A.chinensis could be used as a natural enemy to control E.griscens in different tea plantations due to the better predation ability at different temperatures.This study provide theoretical basis and practice guidance for the safe and high-quality production of tea and the sustainable development of tea plantations.