Abstract: A wood borer parasitoid, Dastarcus helophoroides is an effective natural enemy as biocontrol agent for those pests in China. However, it has been difficult for mass rearing the parasitoid for biocontrol applying. In order to solve the problem, we carried out a study on the technique of mass rearing the parasitoid. We chose Zophobas atratus (Fabricius) as a substitute host for rearing its larvae, and use the artificial diets in its adult stage. We reared D. helophoroides for four generations in laboratory continuously, and analyze the spawning amount, the preoviposition period, the sex ratio, the body length, the body width, the body weight, the hatching rate of the eggs and the parasitism rate. The effect of artificial feed and substitute hosts on the multiple generations of rearing in the house was analyzed. The results showed that, the body length, body width, body weight of the parasitoid adults decreased with the increase of the indoor rearing generations; the adults preoviposition period was prolonged with the increase of the rearing generations, which could be effectively restrained by adding vitamins in the artificial diet; with the increasing of the number of generations and the extension of the time, the average number of eggs layed by per female increased; the ratio of male to female was not consistent with 1:1 after four generations of reproduction with substitute hosts; the hatching rate of the eggs and the indoor parasitism rate of the newly hatched larvae were almost not affected by the four generations of indoor mass rearing. Compared various reproductive biological characteristics indexes of different artificial diets and different hosts, it was found that the preoviposition period of improving artificial diet decreased significantly after feeding for four generations; the number of males fed by Z. atratus pupae was significantly higher than that of females, oppositely, the number of females in the second and third generations reared by improving diet and the parasitoid original host Monochamus alternatus larvae was significantly higher than that of males. To sum up, by using the substitute host Z. atratus pupae could cause imbalance of sex ratio of the parasitoid offspring, through improving artificial diet formula and reared alternatively by the original host cerambycid, it had a little impact on reproductive biological characteristics after multiple generations of indoor mass rearing, and it could be applied for mass rearing the parasitoid for biocontrol practice.

Key words: Dastarcus helophoroides, Zophobas atratus, artificial diets, substitute host, mass rearing