太原郊区小菜蛾幼虫和蛹期寄生蜂资源调查

Investgation on Parasitoids from Larvae and Pupae of Diamondback Moth, Plutella xylostella L. in the Suburb of Taiyuan

[目的]明确太原郊区小菜蛾幼虫期和蛹期主要寄生性天敌种类及其田间消长动态。[方法]田间采集不同十字花科蔬菜上小菜蛾幼虫和蛹,室内饲养、观察,记录和统计寄生蜂种类和数量。[结果]太原郊区十字花科蔬菜上小菜蛾幼虫期和蛹期共有8种寄生蜂,其中有5种经鉴定为半闭弯尾姬蜂[Diadegma semiclausum(Hellen)]、菜蛾盘绒茧蜂[Cotesia plutellae(Kurdjumov)]、颈双缘姬蜂[Diadromus collaris(Gravenhorst)]、菜蛾啮小蜂(Oomyzus sokolowskii Kurdumov)和绒茧金小蜂[Trichomalopsis apanteloctena(Crawford)];半闭弯尾姬蜂是该地区小菜蛾寄生蜂的优势蜂种,占89%;6月上中旬和8月底至9月初是小菜蛾寄生蜂一年内2个高峰时段,最高寄生率分别为68.1%和64.0%;喷施农药田块小菜蛾幼虫和蛹的寄生率低于未施药田块。[结论]该调查结果为构建基于保护和利用天敌的小菜蛾综合治理技术提供了参考。

[Objective]To investigate the species and population dynamics of parasitoids from larvae and pupae of diamondback moth,Plutella xylostella L.in the suburb of Taiyuan.[Method]Larvae and pupae of diamondback moth were collected from crucifer vegetable fields located in suburb of Taiyuan,and were reared in an artificial climate chamber.After emergence,parasitoids were recorded and identified by observing their characteristics and parasitism rates were calculated.[Result]In total,eight parasitoid species were found,of which five were identified as Diadegma semiclausum,Cotesia plutellae,Diadromus collaris,Oomyzus sokolowskii,Trichomalopsis apanteloctena.Diadegma semiclausum was the dominant species,accounting for 89%of the total numbers parasitized.Two peaks of the parasitization in the field were found from early June to middle June and from later August to early September,with 68.1%and 64.0%of parasitism rates,respectively.However,lower parasitism rates were found in insecticide spraying field than in no insecticide spraying field.[Conclusion]The results provide reference for building integrated pest management system based on protection and utilization of natural enemy against diamondback moth in the suburb of Taiyuan.