松毛虫卵期几种寄生蜂的共寄生现象及其对寄生率的影响

松毛虫赤眼蜂Ｔｒｉｃｈｏｇｒａｍｍａｄｅｎｄｒｏｌｉｍ　Ｍａｔｓｕｍｕｒａ，白跗平腹小蜂ＰｓｅｕｄａｎａｓｔａｔｕｓａｌｂｉｔａｒｓｉｓＡｓｈｍｅａｄ，松毛虫宽缘金小蜂Ｐａｃｈｙｎｅｕｒｏｎ　ｓｏｌｉｔａｒｉｕｍ（Ｈａｒｔｉｇ），松毛虫黑卵蜂Ｔｅｌｅｎｏ－ｍｕｓ　ｄｅｎｄｒｏｌｉｍｕｓｉ　Ｃｈｕ和大蛾卵跳小蜂Ｏｏｅｎｃｙｒｔｕｓｋｕｗａｎａｅ（Ｈｏｗａｒｄ）是松毛虫卵期几种主要寄生蜂。通过对上述几种寄生蜂寄生习性的研究表明：赤眼蜂和平腹小蜂不但能寄生新鲜害虫卵，还可以寄生对方已寄生并已发育１—３天的寄生卵，但羽化率均不高；松毛虫宽缘金小峰不寄生新鲜害虫卵，专门寄生赤眼蜂寄生后已发育１—７天的寄生卵，其中又以赤眼蜂发育３—５天的卵寄生率和羽化率为最高。除赤眼蜂和平腹小蜂可以混合使用外，其它蜂种混用都不同程度地存在相互排挤的现象。如果先让平腹小蜂寄生尔后再让赤眼蜂寄生或先让赤眼蜂寄生，尔后再让跳小蜂或黑卵蜂寄生，能够提高卵块寄生率和充分发挥各自天敌的作用。

INFLUENCE OF MULTIPARASITISM OF EGG PARASITOIDSOF PINE LASIOCAMPIDS ON EFFICACY OFBIOLOGICAL CONTROL

richogramma 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 hasbeen conducted on the habits of parasitism of these parasitoids and the results aresummarized as follows. There existed reciprocal parasitism between Trichogrammadendrolimi and Pseudanastatus albitarsis. They usually attacked the fresh hosteggs, but they also parasitized the eggs that had been parasitized by the otherspecies. In the latter case, the non-cogeneric embryo could develop for 1 to 3days 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 beenparasitized by Trichogramma spp. whose embryo developed for 1 to 7 da.-s. Theparasitization rate and adult emergence of this species were the highest whenthe 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 lelease of other parasitoidswould result in antagonism. If the host egg masses were first parasitized by Pseudanastatus albitarsis and later by Trichogramma dendrolimi or first parasitized byTrichogramma 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.