十字花科蔬菜-小菜蛾-寄生性天敌三营养级系统研究:不同条件下小菜蛾幼虫被寄生率调查

本文根据在深圳、广州、东莞三地对不同蔬菜、不同农事措施、杀虫剂不同施用水平菜地小菜蛾自然种群幼虫被寄生率调查结果，分析十字花科蔬菜－小菜蛾－菜蛾绒茧蜂三种群系统中，蔬菜品种、农事操作、杀虫剂对菜蛾绒茧蜂寄生行为的影响。结果说明：不同蔬菜品种上，小菜蛾幼虫被寄生率有不同程度的差异，以包心菜菜地寄生率最高，超过３０％。十字花科蔬菜与其他非十字花科蔬菜的间作对绒茧蜂的寄生率也存在一定的影响作用。深圳、东莞、广州三个地区，以广州地区小菜蛾幼虫被寄生率较高。化学杀虫剂降低绒茧蜂的寄生率。小菜蛾幼虫的体色与被寄生率也有一定的关系，以体色与背景色一致的个体被寄生率较低

STUDY OF THE TRITROPHIC SYSTEM COMPOSED OF THE CRUCIFEROUS VEGETABLE DIAMONDBACK MOTH (PLUTELLA XYLOSTELLA) PARASITOIDS: THE INVESTIGATION OF THE LARVAE MORTALITY CAUSED BY BRACONID (APANTELES PLUTELLA)

The data were collected from the vegetable fields in Guangzhou, Dongguang, Shenzhen areas, which were managed with different cultural methods, planted with different varieties, sprayed with different insecticides. The effects of these strategies on the parasite behavior of the braconid ( Apanteles plutella) in the tritrophic system composed of the cruciferous vegetable diamondback moth (plutella xylostella,DBM)parasitoid were analyzed inthis paper,The results showed that the mortalities of diamondback moth caused by braconid on different vegetable varieties were different,the highest was on the cauliflower (Brassica oleraceal botrytis),The intercrop of the noncruciferous vegetable with the cruciferous also affected the mortality of the DBM in certain degree.The mortality of DBM in Guangzhou area was the highest compared with the Dongguang and Shenzhen area.The spraying of insecticides to control the pests on vegetable decreased the mortality of DBM. On the same vegetable body color of DBM aftected the mortality caused by the braconid.The individuals,which body.color was similar with the background vegetable,had the lower mortality.