Study On Artificial Rearing Technology Of Propylaea Quatuor-Decimpunctata And Evaluation Of Its Pest Control Function

Propylaea quatuordecimpunctata(Coleoptera: Coccinellidae)is one of key natural enemies within cotton and maize fields in Xinjiang,China,which has unignorably biological control potential for future application.However,mass rearing of this predator and predation ability under different diets are still unclear.This paper examines the use of three aphids,two insects’ eggs and six artificial diets on P.quatuordecimpunctata rearing to evaluate effects on larvae developmental duration,survival rate,adult fecundity,longevity,population index and predation ability.Results are as below:1.Three species of aphids on P.quatuordecimpunctata rearing evaluation.Results showed Aphis gossypii and Myzus persicae had better fitness and rearing effects on P.quatuordecimpunctata than Megoura japonica.The larval survival rates of P.quatuordecimpunctata fed by M.persicae and A.gossypii were 88.33% and 85.83%,respectively,which were significantly higher than those fed by M.japonica(50.83%).In terms of fecundity,the egg production of P.quatuordecimpunctata females fed by M.persicae and A.gossypii were 516.17 and 439.95 eggs/female,respectively,which were significantly higher than those fed by M.japonica(209.00 eggs/female).The intrinsic rate of increase of P.quatuordecimpunctata fed by M.persicae and A.gossypii were 0.2169 and 0.2125,respectively,and the population trend indices were 164.10 and 130.93,respectively,which were higher than those fed by M.japonica.2.Two species of insects’ eggs on P.quatuordecimpunctata rearing evaluation indicated feeding P.quatuordecimpunctata by Sitotroga cerealella and Ephestia kuehniella(Lepidoptera: Phycitidae)eggs were suitable for its development and fecundity.Larvae developmental duration on E.kuehniella was significantly shorter than that on S.cerealella eggs.The larvae survival rate on E.kuehniella eggs was67.00%,higher than that on S.cerealella eggs(61.00%);The egg production on S.cerealella eggs was273.66 eggs/female,which was significantly higher than that on E.kuehniella eggs(183.93 eggs/female).the longevity of females on S.cerealella eggs was significantly higher than that on E.kuehniella eggs.The intrinsic rate of increase of P.quatuordecimpunctata feeding on S.cerealella eggs and E.kuehniella eggs were 0.1446,0.1251,respectively,and population trend indices were 43.45,30.10.Show the S.cerealella for more suitable for the adult population growth.3.Six artificial diets on P.quatuordecimpunctata rearing evaluation showed that the larvae survival rates of the two diets fed with pig liver and Tenebrio molitor and beef and pig liver as the main ingredients were 27.74% and 25.33%,respectively,followed by larvae fed with chicken liver and milk powder,pig liver and honey,pig liver and pork,aphids and Antheraea pernyi pupae as the main ingredients,from highest to lowest(18.67%,3.33%,0.67% and 0.00%).The fertility and longevity of female feeding on pig liver and T.molitor individuals was significantly higher than that on other homemade diets,and the individuals reared on pig liver and T.molitor had some reproductive ability with female egg production of22.00 eggs/female.The intrinsic rate of increase and population trend index of feeding on pig liver and T.molitor were 0.0042 and 1.27,respectively,which could sustain P.quatuordecimpunctata populations as an alternative when natural foods were scarce.P.quatuordecimpunctata feeding with beef and pig liver could not oviposit normally,The larval mortality rate on the other four diets was high,the adult acquisition rate was low,and the adults did not lay eggs.4.The results of the study about effect of different diets on the predation function of P.quatuordecimp unctata showed that the predation function response model of P.quatuordecimpunctata to the 4th instar of A.gossypii was in accordance with Holling type II.The maximum daily predation of P.quatuordecimpunct ata fed on cotton aphid was highest(784.93),followed by diets included pork liver plus beef,pork liver plu s T.molitor,M.persicae individuals,which was the lowest on insects’ eggs;But P.quatuordecimpunctata f ed by S.cerealella or E.kuehniella eggs had shorter searching time than that in high density of A.gossypii.This study emphasized maintenance,promoting effects,functional response of P.quatuordecimpunctat a population in different diets included aphids,insects’ eggs and artificial diets,which could benefit protect ion and application of this predator.Moreover,P.quatuordecimpunctata population establishment,mainten ance and mass production could be improved,in order to biological control of pest in practice.