人工饲料饲养的叉角厉蝽对昆虫的捕食能力评价

Predatory capacity of Eocanthecona furcellate (Wolff) reared with artificial diets

叉角厉蝽Eocanthecona furcellate(Wolff)是广泛分布于热带亚热带地区的一种重要捕食性天敌昆虫。为评估人工饲料饲养的叉角厉蝽的捕食能力,在实验室采用捕食功能反应的方法,以黄粉虫作为中介猎物饲养的叉角厉蝽为对照,评价了人工饲料饲养的叉角厉蝽3龄若虫、5龄若虫以及雌成虫对黄粉虫Tenebriomolitor(L.)幼虫及斜纹夜蛾Spodoptera litura(Fabricius)3龄幼虫、5龄幼虫的捕食效能。结果表明,两种饲料饲养的不同虫态叉角厉蝽的捕食量均随着猎物密度的增加而上升,当猎物密度增加到一定水平,捕食量趋于稳定,其捕食功能反应均符合HollingII模型。人工饲料组饲养的各虫态叉角厉蝽与对照组的对黄粉虫幼虫的捕食量没有明显差异;在饱和猎物密度条件下,人工饲料饲养的叉角厉蝽3龄若虫、5龄若虫以及雌成虫对斜纹夜蛾3龄幼虫的日最大捕食量分别为7.20、9.20、14.60头,对斜纹夜蛾5龄幼虫的日最大捕食量分别4.20、5.80、6.20头,均略低于对照组,但从取食猎物数量上来看,仍保持较强的捕食能力。

Eocanthecona furcellata (Wolff) is an important predatory natural enemy distributed in tropical and subtropical regions. The effect of artificial diets on the predation ability of E.furcellata to the larvae of Tenebrio molitor (L.) and Spodoptera litura (Fabricius) was evaluated with functional response method in laboratory, E.furcellata fed with the larvae of T.molitor were used as the control. The predatory efficiency of E.furcellata (3 rd instar nymph, 5 th instar nymph and female adults) to the larvae of T.molitor and S.litura (3 rd instar larvae and 5 th instar larvae) were evaluated. Results showed that the prey consumed by two types of E.furcellata both increased with the increase of prey density, and when the prey density increased to saturation level, the quantity of prey consumed by E.furcellata tended to be stable. The predatory function responses of E.furcellata in different development stage to the T.molitor and S.litura fit the Holling-II model. No significant difference were observed in the predatory capacity to T.molitor larvae between E.furcellata reared with artificial diets and T.molitor larvae. Under the saturation prey density, the maximum number of 3 rd instar larvae of S.litura consumed by 3 rd instar nymph, 5 th instar nymph and female adults of E.furcellata reared with artificial diets were 7.20, 9.20 and 14.60 daily, respectively, and they were 4.20, 5.80 and 6.20 when provided with 5 th instar larvae of S.litura. Though the quantity of S.litura larvae consumed by E.furcellata reared with artificial diets was fewer than those reared with T.molitor larvae, E.furcellata reared with artificial diets still kept the strong predatory capacity.