单季稻田捕食性天敌的群落组成及两种杀虫剂对其多样性的影响

通过稻田定期定点调查表明，湘阴县单季稻田捕食性天敌群落主要有蜘蛛13科42种，昆虫天敌26种。施用不同杀虫剂对单季稻田捕食性天敌群落多样性和物种丰富度有不同程度的降低作用，锐劲持防治区的多样性指数和丰富度明显高于甲胺磷防治区，就药后个体数量而言，前者是后者的3．32倍。因此认为，单季稻田施用锐劲持对捕食性天敌比甲胺磷更为安全。合理使用杀虫剂对保护和充分利用天敌资源有着重要的意义。

The Community Making up of Predatory Natural Enemies and the Effects of Two Insecticides to the Community Diversity in Single-cropping Paddy Fields

Based on preliminary investigation in fixed position in Xiangyin,42 species 13 families of spider and 26 species of insect natural enemy were found in the community of predatory natural enemies of single- cropping paddy fields. Tile species richness and community diversity of predatory natural enemies raked from dissimilarly by using different insecticides, and which sprayed methamidophos declined more obviously than fipronil. The individual number controlled with fipronil was more than methamidphos at 3.32 times. This paper proved that fipronil was safer than methamidophos to predatory natural enemies for controlling pest in single- cropping paddy fields, and it is beneficial to spray insecticides with reason to protect and take full advantage of natural enemy.