| The green lacewing Chrysopa pallens is an important natural enemy, which can be used in thecontrol of variety of soft-bodies pests, such as aphids, spider mites, scale insects, lepidopteran,whiteflies, thrips and leafhoppers. It has a wide distribution, high adaptability and fecundity and iscarnivorous in both larval and adult stage. Many researches are on its biology, ecology and utilization，but there is still no cost-effective mass-rearing system for the green lacwing up to now. To assess thenatual life table parameters.both soybean aphids and rice moth eggs were fed to larvae and adultsrespectively. In this paper, we evaluate the effect of artificial diets with insect materials yellowmealworms Tenebrio molitor Linnaeus larvae protein, and housefly Musca domestica Linnaeus larvaeprotein on the life history parameters of green lacewing Chrysopa pallens. C. pallens larvae were fedwith soybean aphids Aphis glycines and subsequently adults were supplied with4kinds of artificialdiets. At the meantime, both soybean aphids and rice moth eggs were fed to larvae and adultsrespectively, to assess the life table parameters. Before this we screened the suitable formulation ofartificial diet. The main results are as follows:1） Screening three formulations of artificial diet, paste, gel and powder, we knew that powder wasthe most suitable of the three. The powder artificial diet is easy to process and has a long shelf life, andit has the smallest interference on the ingestion of adults.2） Nutrirtion analysis of the rice moth egg and artificial diets were carried out. Results showedthat there is no difference in the amount of crude protein between the artificial diets and the rice mothegg powder, but the amount of crude fat is much lower, while sugar is much higher in the artificial dietsthan those of the control. Both the composition of the amino acids and fatty acids were different fromthe aphids and rice moth egg powder. In the future study, add or omit amino acid and fatty acid will behelpful to improve the artificial diet.3） Rice moth egg was a suitable alternative food of C. pallens. Results revealed that rice motheggs had no bad effect on cocoon developmental duration, survival rate, and adult longevity of C.pallens when compared with the soybean aphids. It will not cause sex differentiation. In contrast to this,precocious stage of both sexes，pre-oviposition period and longevity of females were prolonged1.5d~1.7d,4.8d and8.3d. The cocoon size and body length were a little smaller than the control. Thefemales can lay over900eggs in the rice moth egg group, while1010eggs in the soybean aphid group,and egg hatchability were improved by5%.4） The effects of artificial diets on the growth and feduncity of green lacewing adults showed thatall the four artificial diet which based on yellow mealworn or housefly larvae defatted powder can beused in mass rearing of the green lacewing adults. Most lacewing individuals can survival, but there aresignificant differences between different groups, especially in the female fecundity. Artificial diets had no effect on the survival rate, but the pro-oviposition periods were prolonged by13to21days andlongevity of adults was prolonged by18to37.1days. Artificial diets improved the egg hatchability by4%to11%, but the fecundity was much lower in the tests of artificial diets, which were616,574,245and262in the four artificial diets groups, while the number was1012in control.Rice moth eggs can be used as the alternative food of C. pallens, it can be used as thesupplementary food in maintaining lacewing populations, for it relatively high costs. Powder diet is themost suitable formulation, and4kinds of artificial powder diets were used to rear the lacewing adults,most individuals can survival and females lay different numbers of eggs. Lacewings with the highestfecundity were reared on YAD-1diet, which contained10parts of yellow mealworm defatted powder,4parts of whole egg powder,2parts of sucrose and2parts of camellia pollen, while lacewings rearedwith YAD-2diet which contained15.31parts of yellow mealworm defatted powder had the longestlongevity. However artificial diets: HAD-1and HAD-2, based on the housefly larvae defatted powderdid not perform well in fecundity, but the surivival rates in these group were normal. |
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