Impact Of Artificial Diets On The Growth And Reproduction Of Neoseiulus Californicus

As an important commercialized predatory mite internationally,Neoseiulus californicus is still being raised in a large scale by the traditional mode of “host plant-spider mite-predatory mite”.Neoseiulus californicus is a selective predatory mite in tetranychidae,which can be fed on pollen as the alternative food.In order to reduce the cost of large-scale raising of Neoseiulus californicus,the development of artificial diet has become a new research direction.In this study,Neoseiulus californicus was selected as the research object to screen the formulas of artificial diet added with different nutritional sources,and study the effect of artificial diet on the growth,development and reproduction of Neoseiulus californicus and the effect of artificial diet on its offspring.The main results are as follows:1.Selection of the feeding device and formula of artificial feedWe have studied the effects of the feeding experimental device of two kinds of artificial feeds and eight kinds of artificial feeds made of honey,sucrose,yeast extract,tryptone,fresh egg yolk with different proportions of shrimp egg,tussah pupa haemolymph and tussah egg haemolymph on the reproduction of the female adults of Neoseiulus californicus and have selected the appropriate experimental feeding device and the artificial feed formula with better feeding effect.The results revealed that the female adult mites fed by osmosis method could survive 18 days,and the amount of eggs laid was 7.3.There was no significant difference in the spawning period and egg laying amount between female adult mites fed on artificial diet added with 20%,30%,40% and 50% of nutritional sources respectively,however,there was difference in the spawning rate,which was0.95/day/female adult mite for those fed on artificial diet added with 20% of nutritional sources and 0.75/day/female adult mite for those fed on artificial diet added with 50%.When the proportion of all 3 different nutritional sources was 20%,the raising effect of tussah pupa haemolymph was the best,with the spawning period of female adult mites lasting 19 days and the egg laying amount reaching 25.7.We studied that the artificial feed made by penetration method with 20% tussah pupa haemolymph shows the best feeding effect.2.Effects of artificial feed on the development and reproduction of Neoseiulus californicusThe effect of artificial diet on the growth,development,reproduction and offspring of Neoseiulus californicus was studied by using 2 kinds of artificial diet formulas with better raising effect.The development duration of male and female Neoseiulus californicus fed on artificial diet added with tussah pupae was 9.59 days and 9.23 days respectively,and that of male and female Neoseiulus californicus fed on artificial diet added with tussah eggs was 10.66 days and 9.97 days respectively.The spawning period of Neoseiulus californicus fed on artificial diet added with tussah pupae and tussah eggs was 10.2 days and 7.4 days respectively,and the egg laying amount was 7.0 and 4.1respectively.The development duration of the male and female offspring of Neoseiulus californicus fed on the 2 kinds of artificial diet was also prolonged to 10.13 days and9.75 days respectively and 11.50 days and 11.20 days respectively,both with adult mite rate less than 20%.Eating artificial feed has a significant effect on the development and reproduction of Neoseiulus californicus,which can prolong their development period,reduce the reproduction capability of the female adults and impact the quality of their offspring.3.Effects of different feeding experiences at different phases on the reproduction and offspring of female mitesAfter the mating of the male and female mites eating different foods for their developing,and then feeding different food to them in the period of spawning,we studied that the phase of eating artificial feed is the source of the effects of the artificial feed on the reproduction and offspring of Neoseiulus californicus.The result shows that the phase is 66 h and 45 h before spawning by the female mites who develop by eating the artificial feed made of tussah pupa haemolymph,and the offspring is sexed at 0.67 and 0.58;2.4d and 4.1d before spawning by the female mites who develop by eating artificial feed made of tussah egg haemolymph and the offspring is sexed at 0.65 and0.56.The yield of the female adults who spawn by eating artificial feed made of tussah pupa haemolymph is 19.6 eggs per female and 15.1 eggs per female;that of the female adults who spawn by eating artificial feed made of tussah pupa haemolymph is 5.2 eggs per female and 2.6 eggs per female respectively.The feeding of artificial diet during the period of young mites mainly affected the pre-spawning period and sex ratio of offspring of female adult mites,while the feeding of artificial diet during the spawning period mainly affected the egg laying amount.The reproductive capacity of male and female mites fed on artificial diet during the development period basically recovered after being fed on Tetranychus urticae during the spawning period.