宁波地区小菜蛾幼虫期和蛹期寄生蜂调查

小菜蛾Plutella xylostella是十字花科蔬菜最重要的世界性害虫,保护和利用寄生性天敌是控制小菜蛾的重要手段。为有效控制小菜蛾在蔬菜上的为害,减少农药用量,作者于2007年4月至2009年1月对宁波地区小菜蛾幼虫期和蛹期主要寄生性天敌种类及其田间自然被寄生率进行了调查。结果表明,宁波地区十字花科蔬菜上小菜蛾幼虫期和蛹期共有8种原寄生蜂（菜蛾盘绒茧蜂Cotesia vestalis、螟蛉盘绒茧蜂Cotesia ruficrus、颈双缘姬蜂Diadromus col-laris、东方长颊姬蜂Macromalon orientale、棉铃虫齿唇姬蜂Campoletis chlorideae、无脊大腿小蜂Brachymeria excarinata、齿唇姬蜂Campoletissp.、弯尾姬蜂Diadegmasp.）、1种兼性寄生蜂（菜蛾啮小蜂Oomyzus sokolowskii）和5种重寄生蜂（盘背菱室姬蜂Mesochorus discitergus、粘虫广肩小蜂Eurytoma verticillata、稻灿金小蜂Trichomalopsis oryzae、绒茧灿金小蜂Trichomalopsis apanteloctena和啮小蜂Tetrastichussp.）,其中优势种为菜蛾啮小蜂和菜蛾盘绒茧蜂,分别占62.23%和31.19%,同时,小菜蛾幼虫期田间自然被寄生率普遍高于蛹期。另外,菜地蔬菜品种的多样性有利于寄生蜂的保护和利用。

Hymenopteran Parasitoids from Larvae and Pupae of the Diamondback Moth, Plutella xylostella in Ningbo, China

The diamondback moth,Plutella xylostella,is one of the most destructive insect pests of cruciferous crops throughout the world.The hymenopteran parasitoids are important natural enemies for controlling the insect pest.In this paper,the hymenopteran parasitoids of the larvae and pupae of the diamondback moth in the field in Ningbo were investigated from April 2007 to January 2009.In total,four-teen parasitoid species were found,of which eight are primary parasitoids（Cotesia vestalis,Cotesia ruficrus,Diadromus collaris,Macromalon orientale,Campoletis chlorideae,Brachymeria excarinata,Campoletis sp.and Diadegma sp.）,one facultative hyperparasitoid（Oomyzus sokolowskii） and five hyperparasitoids（Mesochorus discitergus,Eurytoma verticillata,Trichomalopsis oryzae,Trichomalopsis apanteloctena and Tetrastichus sp.）.Generally,Oomyzus sokolowskii and Cotesia vestalis were the dominant species,accounting for 62.23% and 31.19% of the total numbers,respectively.Higher parasitism rate was found on larval stage of diamondback moth than that on pupal stage in the field.The results also indicated that high diversity of vegetable varieties in the field is favorable to the protection of parasitoids.