环斑猛猎蝽对斜纹夜蛾低龄幼虫的捕食功能反应

为挖掘环斑猛猎蝽(Sphedanolestes impressicollis)对斜纹夜蛾(Spodoptera litura)的捕食潜力，在室内条件下研究了环斑猛猎蝽4龄若虫对斜纹夜蛾1龄、2龄和3龄幼虫的捕食功能、寻找效应、环斑猛猎蝽不同密度对捕食斜纹夜蛾的干扰效应以及捕食空间大小对环斑猛猎蝽捕食功能的影响。结果显示，4龄环斑猛猎蝽若虫对低龄斜纹夜蛾幼虫的捕食功能反应与Holling II模型相符，对1~3龄斜纹夜蛾幼虫的瞬时攻击率分别为0.979、0.999和0.164，处理时间分别为0.013、0.020和0.018 d，最大日捕食量分别为74.5、51.2和6.1头。4龄环斑猛猎蝽若虫的寻找效应与斜纹夜蛾低龄幼虫密度呈负相关，对斜纹夜蛾低龄幼虫的捕食作用率随自身密度的增加而下降。在捕食1龄斜纹夜蛾幼虫时，环斑猛猎蝽4龄若虫自身密度对其捕食能力干扰最大。因此4龄环斑猛猎蝽若虫对低龄斜纹夜蛾幼虫具有一定的捕食能力，可用于烟田斜纹夜蛾幼虫的绿色防控。 

Predatory functional response of Sphedanolestes impressicollis to young larvae of Spodoptera litura

To explore the predation potential of Sphedanolestes impressicollis on Spodoptera litura, the predatory function and searching effect of the 4th instar nymphs of S. impressicollis on the 1st, 2nd and 3rd instar larvae of Spodoptera litura, the interference effect of different densities of the 4th instar nymphs of S. impressicollis on its predatory function on S. litura, and the influence of predatory space size on the predatory function of the 4th instar nymphs of S. impressicollis on the 1st, 2nd and 3rd instar larvae of S. litura were studied in laboratory. The results showed that the predatory functional response of the 4th instar nymphs of S. impressicollis on young larvae of S. litura was consistent with Holling Ⅱ model, and their instantaneous attack rates on the 1st, 2nd and 3rd larvae of S. litura were 0.979, 0.999 and 0.164 with the treatment time of 0.013, 0.020 and 0.018 d and the maximum daily predatory capacities of 74.5, 51.2 and 6.1 larvae, respectively. The searching effect of the 4th instar nymphs of S. impressicollis was negatively correlated with the density of young larvae of S. litura, while the predation rate of the 4th instar nymphs of S. impressicollis on the larvae of S. litura decreased with the increase of their density. When preying on the 1st instar larvae of S. litura, the density of the 4th instar nymphs of S. impressicollis had the most interference effect on their preying ability. Therefore, the 4th instar nymphs of S. impressicollis have certain predation potential on the young larvae of S. litura, and can be used for the green control of young larvae of S. litura in tobacco fields.