| Diglyphus isaea Walker is an important parasitoid wasp for controlling leafminers. At present, D. isaea reared by traditional methods was small and had low longevity and fecundity. At the same time, the cost of rearing was high. So mass rearing and large-scale application of D. isaea were limited. Strengthening the basic and applied research was very important for mass rearing and application of D. isaea, including selecting the host which was big, easily reard and had high fitness and low cost and lengthening the survival time by different supplementary food. In this paper, D. isaea were reard using both Liriomyza sativae Blanchard and Chromatomyia horticola Goureau, in order to prove the fitness of Chromatomyia horticola Goureau as a host for rearing D. isaea. The effects of different supplementary food on longevity and fecundity were also studied. And the mass rearing system of D. isaea were further discussed. The results provide theoretical reference and technology support for mass rearing and releasing of D. isaea in the future. The experimental results as follows:While L. sativae and C. horticola were both presence, D. isaea had strong selective for the two hosts. Emergence rate and sex ratio (% female) of D. isaea which parasitism on C. horticola (♂︰♀=1︰1.04) were higher than that on L. sativae (♂︰♀=1︰0.95). In addition, the development time of progeny parasitism on C. horticola (10.6d) was significantly shorter than that on L. sativae (11.5d). D. isaea fed on C. horticola for 5 generations continuously and then back inoculation on L. sativae, compared to feeding on L. sativae always, the death rate, emergence rate and sex ratio (% female) were significantly increased. HTL which responsed the size and nutritional status of wasps showe that the hind tibia length of D. isaea from C. horticola was significantly longer than that from L. sativae, and the females were also significantly longer than the males. Moreover, the average of longevity C. horticola was longer than L. sativae, which fully verified the fitness of C. horticola as a host for rearing D. isaea.Effects of different supplementary food on the longevity of D. isaea were studied. The results showed that the difference in longevity between male and female D. isaea was not significant. The longevity of wasps fed with sugars was 5-9-fold longer than those fed with bovine serum albumin, water and no food. Moreover, the longevity of the wasps fed with 15% glucose, 15% honey or 15% sucrose could come to 47.0±3.5d, 45.7±2.9d and 44.5±3.5d. It was 15-fold longer in comparison to those without food. The results could provide useful information for lengthening the shelf life of D. isaea.Effects of different supplementary food on the fecundity of female D. isaea were also studied. The ovipositing duration of female D. isaea fed with sucrose, honey or glucose was over 1-fold longer in comparison to those without food, and the total eggs were 1-2-fold more than those without food, and the number of emergence and sex ratio (% female) were also significantly increased. Usually, the number of eggs laid daily by female D. isaea could come to the maximum among the 4-9th days after emergence. The female D. isaea fed on 15%sucrose had not only the longest ovipositing duration but also the maximum of number of eggs laid daily, total eggs and emergence. Considering the longevity, ovipositing duration, eggs laid daily, total eggs, emergence and sex ratio (% female) of D. isaea, 15%sucrose was the best supplementary food style, and it could be widely used in the mass rearing and large-scale application of D. isaea.Generally, it would be finished 2 production cycles of D. isaea every month. The results showed that the Phaseolus vulgaris of 13d, 30~50 C. horticola every 4 leaves and 1︰10~15 releasing ratio of D. isaea were the best combination. Every combination in every production cycle could get 96 D. isaea adults. The combination could greatly save the costs and provide theoretical reference for mass rearing even commercial production of D. isaea.
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