弯尾姬蜂与菜蛾啮小蜂的种间竞争关系  

Interspecific Competition Between Two Parasitoids Diadegma semiclausum and Oomyzus sokolowskii in Plutella xylostella

作　　者：施祖华[1] 李庆宝[1] 李欣[1] 刘树生[1] 

机构地区：[1]浙江大学应用昆虫学研究所,杭州310029

出　　处：《中国生物防治》2003年第3期97-102,共6页Chinese Journal of Biological Control

基　　金：国家自然科学基金项目(39870505);澳大利亚国际农业研究中心合作项目(CS2/1998/089)部分内容

摘　　要：在室内25℃下,同时让弯尾姬蜂和菜蛾啮小蜂寄生或只让其中一种蜂寄生3龄小菜蛾幼虫,研究了两种寄生蜂间的竞争关系。两种蜂均可产卵寄生已被另一种蜂寄生过的寄主幼虫。当寄主先供弯尾姬蜂寄生,然后于0～4d内再供菜蛾啮小蜂寄生,所育出的蜂几乎全部为弯尾姬蜂。当寄主先供菜蛾啮小蜂寄生,然后再供弯尾姬蜂寄生时,若后者产卵发生在前者产卵后1d内,育出的仍基本上是弯尾姬蜂;随后随时间间隔的延长所育出菜蛾啮小蜂的比例增加,3d以后全部为啮小蜂。结果表明,两种寄生蜂间可以发生直接食物资源竞争,竞争结果依两种蜂的产卵先后顺序及时间间隔长短而异。Interspecific competition between Diadegma semiclausum Hellen (Hym.: Ichneumonidae) and Oomyzus sokolowskii (Kurdjumov) (Hym.: Eulophidae) was investigated at 25℃ in the laboratory, by exposing the third instar larvae of diamondback moth, Plutella xylostella (L.) (Lep.: Plutellidae) to either species alone or the host larvae already exposed to one species to the other. Both D. semiclausum and O. sokolowskii could lay eggs into the host larvae which had previously been parasitized by other species, leading to occurrence of multiparasitized hosts. When host larvae were exposed first to D. semiclausum and then to O. sokolowskii in time intervals of 0-4 d, ensuing parasitoid adults from the multiparasitized host larvae were nearly always D. semiclausum. When host larvae were first exposed to O. sokolowskii and then to D. semiclausum, the ensuing parasitoid adults from the host larvae were still always D. semiclausum when the oviposition of the latter took place within 1 d of that by the former parasitoid, but the proportion of O. sokolowskii adults increased as the time intervals between the two exposures increased and came to one hundred percent when the oviposition of the latter took place 3 d after that by the former parasitoid. These results suggest that competition for food resource between these two parasitoids may occur directly, and the final outcome of the competition depends on the order and interval of the two ovipositions.

关 键 词：弯尾姬蜂 菜蛾啮小蜂 种间竞争 寄生蜂 蔬菜害虫 天敌 

分 类 号：S436.3[农业科学—农业昆虫与害虫防治] S476.3[农业科学—植物保护]