小红瓢虫对埃及吹绵蚧的捕食功能的研究

The study of predation of Icerya aegyptiaca by Rodolia pumila

运用普通生态学方法对埃及吹绵蚧的主要捕食性天敌小红瓢虫的捕食功能进行研究。结果显示,小红瓢虫对埃及吹绵蚧的密度反应为HollingⅡ型,圆盘方程拟合后的瞬时攻击率为0.577,处理时间为0.019;通过Hassell模型拟合,小红瓢虫自身密度增加导致的干扰效应为0.434;根据汪世泽提出的功能反应新模型,拟合后估计的小红瓢虫最大捕食量为24.7头,最佳捕食密度为16.5头。综合分析小红瓢虫的捕食功能特性,认为不宜单用小红瓢虫防治埃及吹绵蚧。

Icerya aegyptiaca was regarded as a serious pest for ornamental plants especially in South China featured with very wide range of diet, strong reproduction ability and easy spreading. Predation oflcerya aegyptiaca by Rodolia pumila was investigated under the laboratory condition in this work. The result indicated that predation response of Rodolia pumila fitted Holling type II functional response with instant attacking rate is 0.577 and treating time is 0.019. According to Hassell model, the factor describing disturbing effect of increasing predator density was estimated to be m=0.434. The potential predating ability and the optimal prey density have been estimated to be a=24.7 and b=16.5 respectively by Wang＇s new model. Considering comprehensive parameters related to predation, Rodolia pumila might be unqualified to be independent agent for biological control of lcerya aegyptiaca.