东亚小花蝽对草地贪夜蛾1龄幼虫的捕食作用

Functional response of Orius sauteri to the 1st-instar larvae of fall armyworm Spodoptera frugiperda

为明确天敌昆虫东亚小花蝽Orius sauteri对草地贪夜蛾Spodoptera frugiperda幼虫的捕食潜力,在室内测定东亚小花蝽5龄若虫和成虫对草地贪夜蛾1龄幼虫的日捕食量,并对其捕食功能、搜寻效应和干扰效应进行分析。结果表明:东亚小花蝽5龄若虫和成虫对草地贪夜蛾1龄幼虫的捕食功能反应符合Holling II模型;东亚小花蝽5龄若虫对草地贪夜蛾1龄幼虫的日最大捕食量、瞬时攻击率和处理单头猎物的时间分别为20.833头、0.747和0.048 d;东亚小花蝽成虫对草地贪夜蛾1龄幼虫的日最大捕食量、瞬时攻击率和处理单头猎物的时间分别为11.236头、1.355和0.089 d。东亚小花蝽的日捕食量与草地贪夜蛾密度呈正相关,搜寻效应与草地贪夜蛾密度呈负相关。东亚小花蝽自身密度对其捕食作用的干扰符合Hassell模型,对草地贪夜蛾1龄幼虫的捕食作用率随自身密度的增加而降低。

In order to ascertain the potential predation capacity of the natural enemy Orius sauteri on the larvae of fall armyworm Spodoptera frugiperda, the daily predation quantity of the 5 th-instar nymph and adult of O. sauteri on the 1 st-instar larvae of S. frugiperda were determined in the laboratory, and the predatory functional response, searching efficiency and mutual interference effect were analyzed.The results showed that the functional responses of the 5 th-instar nymph and adult of O. sauteri to the1 st-instar larvae of S. frugiperda fitted well with Holling II model. Maximum daily predation, instantaneous attack rate and handling time of the 5 th-instar nymph of O. sauteri to the 1 st-instar larvae of S.frugiperda were 20.833 heads, 0.747 and 0.048 d, respectively. Maximum daily predation quantity, instantaneous attack rate and handling time of the adult of O. sauteri to the 1 st-instar larvae of S. frugiperda were 11.236 heads, 1.355 and 0.089 d, respectively. The daily predation quantity of O. sauteri was positively correlated with its prey density, and the searching efficiency was negatively correlated with its prey density. The mutual interference effect of its own density on predation fitted well with Hassell model, and the predation ratio on the 1 st-instar larvae of S. frugiperda decreased with increasing density of the spider.