Studies On Feeding And Starvation Tolerance Of Arma Custos(Fabricius)

Arma custos?Fabricius??Hemiptera:Pentatomidae?is an important predatory natural enemy,which has a good control effect on more than 40pests in agriculture and forestry,however,there is no in-depth research reports on the selection of preys and the corresponding rearing techniques of A.custos.In this paper,the growth and development differences of A.custos fed by different preys were studied under the conditions of 25?±1?,70%±5%RH and light cycle L:D=16 h:8 h,the quantity and time of prey release and the ability of A.custos to resist starvation were measured under the conditions of artificial feeding,which provided basis for improving the rearing mass reproduction techniques of A.custos.The larvae of Mythimna separate?Walker?,Tenebrio molitor?L.?and Spodoptera litura?Fabricius?were used to rear A.custos.The results showed that there was no significant difference in body weight among nymphs except for the 2^nd instar nymph,but it was significantly higher than nymph reared by S.litura.In the same way,the development duration of nymphs reared by M.separate and T.molitor was significantly shorter than than nymph reared by S.litura,but there was no significant difference between them.The nymph mortality rate of A.custos reared by S.litura was higher than that other two preys,there was no significant difference in nymph mortality between those treated with M.separate and T.molitor.The results showed that the maximum food available for T.molitor with an average weight of 131.1 mg was 106.1 mg and attacked by 40 4^thinstar nymphs of A.custos for 48 hours.In this paper,the amount of consumption of T.molitor in different stages was determined.The results showed that there were significant differences in the amount of food consumed by nymph between 2^nd to 5^thinstar,male,female at different time periods,among which,the amount of food consumed by A.custos was concentrated in the first hours after the injection of T.molitor.The food consumes gradually decreased with the extension of time within 48h,among them,the 2^nd and 3^rd instar nymphs,the female and male adults showed the characteristic of first increasing,then decreasing and then increasing after feeding for the first24 hours.In addition,there was no significant difference between the density of T.molitors and A.custos consumption.The consumption of nymph instar 2^rd to 5^th,female,male adult of A.custos by a single was3.43 mg,9.23 mg,13.33 mg,11.77 mg,12.60 mg,and 11.20 mg respectively.The results of starvation test showed that the survival time of 2?5instar nymphs,female and male adults of A.custos treated by water supply was 226.4 h,227.6 h,265.2 h,362.8 h,265.2 h and 238.4 h,respectively.Under anhydrous treatment,the survival time of 2?5 instar nymphs,female and male adults were 129.2 h,142.4 h,215.2 h,176.4 h,198.8 h and 141.6 h,respectively.The starvation tolerance of the 4^thinstar nymphs was the strongest without water.The results showed that the survival time of water treatment was significantly longer than that of anhydrous treatment except for 4^th instar nymphs.