The selective predation of Cantheconidea furcellate Wolff on the different instar larvae of Spodoptera litura in coexistence of three-age type
叉角厉蝽对斜纹夜蛾不同龄期幼虫的选择捕食作用

Selective predation of \?ntheconidea furcellate \% Wolff on the 2nd instar larvae,4th instar larvae and the 6th instar larvae of \%spodoptera litura\% in coexistence of three prey\|age types was studied.The quadratic function models,describing the relationship between the number of prey attacked and the densities of predator and its preys,were established by the rotational composite design of quadratic regression.Based on the predation models,the selective preying ratios could be calculated under the combination of the different densities of three prey\|age types and the predator.