Abstract: Trichogramma dendrolimi Matsumura, Pseudanastatus albitarsis Ashmead, Pachyneuron nawai Ashmead, Telenomus dendrolimusi Chu and Ooencyrtus kuwanae (Howard) are the main egg parasitoids of the pine lasiocampids. A research has been conducted on the habits of parasitism of these parasitoids and the results are summarized as follows. There existed reciprocal parasitism between Trichogramraadendrolimi and Pseudanastatus albitarsis. They usually attacked the fresh host eggs, but they also parasitized the eggs that had been parasitized by the other species. In the latter case, the non-cogeneric embryo could develop for 1 to 3 days but the rate of adult emergence was very low. On the other hand, Pachyneuronnawai did not parasitize fresh host egg; it only parasitized eggs that had been parasitized by Trichogramma spp. Whose embryo developed for I to 7 da s. The parasitization rate and adult emergence of this species were the highest when the non-cogeneric embryo had developed for 3 to 5 days. Telenomus dendrolimusiand Ooencyrtus kuwanae, however, only parasitized fresh host eggs. During biological control of pine lasiocampids, only Trichogramma dendrolimi and Pseudanastatusalbitarsis could be released at the same time; the mixed release of other parasitoidswould result in antagonism. If the host egg masses were first arasitized by Fseudanastatus albitarsis and later by Trichogramma dendrolimi or first parasitized by Trichogramma dendrolimi and later by Telenomus dendrolimusi or Ooencyrtus kuoanae, the rate of parasitization would become higher and thus would result in better effect in controlling the pest.

Key words: pine lasiocampid——egg parasitoid——multiparasitism——rate of parasitizatiou