小菜蛾蛹主要天敌颈双缘姬蜂的生物学

BIONOMICS OF DIADROMUS COLLARIS (HYMENOPTERA:ICHNEUMOMONIDAE), A MAJOR PUPAL PARASITOID OF PLUTELLA XYLOSTELLA

颈双线姬蜂Diadromuscollaris是小菜蛾蛹的重要寄生蜂。该文报道了此蜂的羽化、产卵、交配、发育、繁殖、存活等生物学、生态学特性以及农药残留对其成蜂毒性等。在25℃下，雌蜂羽化后1～2d即可产卵，第3～7d达到产卵高峰，每雌一生平均产卵寄生43．8头寄主，平均产卵寄生期为11．5d。幼虫共有5个龄期，25℃下卵期和各龄幼虫期1～2d，蛹期5～6d，雌、雄蜂的发青田期无显著差异，在15℃、17．5℃、20℃、22．5℃、25℃、27．5℃、30℃和32．5℃时从卵发育至成虫的平均历期为30．6d、22．5d、17．8d、145d、12．1d、11.1d、10.3d和10.2d。发育起点温度为7．4℃，有效积温为225．1日度。发育、存活和产卵寄生适温范围约17～30℃。15℃下成蜂可贮存20～30d。Bt、抑太保、害极灭等对成蜂无直接的残留毒性，辛硫磷、灭多威、杀虫双等则有较高的毒性，杀灭菊酯有微毒性。

Diadromus collaris is a major pupal parasitoid of Plutella xylostella in Hangzhou, China. This paper reports the observations of several aspects of its biology and the effect of several insecticides on its adults. At 25℃, adult females started oviposition on 1～2 d after emergence and reached their oviposition peak on 3～7 d. On average , the total number of pupae parasitized by a mated female was 43. 8 and the oviposition period was 11. 5 d. The parasitoid had five larval instars. At 25℃, the developmentdurations for egg and each larval instar were 1～2 d, and 5～6 d for the pupa respectively. The mean development periods from egg to adult at 15C, 17℃ 5℃, 20. 0℃, 22. 5℃,25. 0℃, 27. 5℃, 30. 0℃ and 32. 5℃ were 30. 6, 22. 5, 17. 8, 14. 5, 12. 1, 11. 1 , 10. 3and 10. 2 d respectively. There was no significant difference in the developmental time between male and female. The temperature threshold and the summation of effective temperature for the development of whole immature stage were 7. 4℃ and 225. 1 day degrees. A temperature range of 17℃ to 30℃ was favorable for the development, survival and reproduction of the parasitoid. The adults could be stored for 20～30 d at 15℃.Phoxim, methomyl and shachongshuang caused quick and high mortality to the adults,fenvalerate was moderately toxic, Bt, chlorfluazuron and abamectin appeared harmless to the adults.