Abstract: In the laboratory, rearings conducted in Beijing, O. furnacalis was used as the factitious host of S. guani, .an important parasitoid of longhorn beetles, Cornborer larvae reared with the artificial diet were induced into diapause by manipulating the rearing temperature,. humidity and photophase before they were use.d in the rearings. The parasitization, of the larvae by the parasitoid was 69.1%. The parasitoid completed its life cycle in the host larva in 30 days. Each host could produce an average of 35.7 wasps. The wasps were stored at 10℃ for 6 months with no significant influence on their parasitical ability. Releasing the mass reared wasps in a field of 7 ha to control two cerambycid herb pests, Xylotrechus grayii on Lonicera japonica and Phytoecia nefiventris on chrysanthemum resulted in over 70% parasiti2ation.