氟啶虫酰胺亚致死浓度处理棉蚜对十一星瓢虫捕食功能反应的影响

【目的】研究氟啶虫酰胺亚致死浓度处理棉蚜对十一星瓢虫捕食功能反应的影响,为合理使用杀虫剂和协同生物防治防控棉蚜提供科学依据。【方法】测定氟啶虫酰胺对棉蚜的毒力,以供试药剂的LC₂₅、LC₅₀为处理浓度,采用浸叶法处理棉蚜,选取活体棉蚜作为十一星瓢虫的食物,分析对其捕食功能反应的影响。【结果】饲喂氟啶虫酰胺不同亚致死浓度处理棉蚜后,十一星瓢虫捕食功能反应等参数及寻找效应均有一定影响,且随药剂浓度增加,对其捕食能力影响越大。饲喂氟啶虫酰胺LC₅₀处理的棉蚜后,十一星瓢虫日捕食量及搜寻能力显著降低,与对照相比,十一星瓢虫1、2、3、4龄幼虫和成虫的瞬时攻击率分别下降0.38%、7.18%、2.19%、16.83%、1.41%,处理一头棉蚜所用的时间分别延长0.002 4 d、0.001 6 d、0.000 6 d、0.000 5 d、0.000 1 d,日最大捕食量分别下降0.72、2.52、7.76、7.01、1.17头/皿。【结论】饲喂氟啶虫酰胺亚致死浓度处理棉蚜对十一星瓢虫1~4龄幼虫及成虫的瞬时攻击率降低,处理棉蚜所用时间延长,日最大捕食量下降。其中饲喂氟啶虫酰胺LC₅₀处理棉蚜对十一星瓢虫各虫态捕食功能有显著影响。

Effects on Predation Response of Coccinella undecimpunctata Fed on Aphis gossypii Treated with Sublethal Doses of Flonicamid

【Objective】 To provide a scientific basis for the rational use of pesticides and the cooperative biological control of Aphis gossypii by studying the effects on predation response of Coccinella undecimpunctata feeding on A. gossypii treated with sublethal doses of flonicamid. 【Methods】 According to the results of toxicity determination of LC₂₅ and LC₅₀ of flonicamid on A. gossypii, the influence of predation response of C. undecimpunctata feeding on A. gossypii treated with sublethal doses by the leaf soaking method were determined. 【Results】 The results showed that A. gossypii treated with flonicamid of different concentrations had certain influence on the predation function response and search effect of C. undecimpunctata, and with the increase of the concentration of the insecticides, the effect on the predation ability was greater. Especially after feeding A. gossypii treated with flonicamid LC₅₀, the daily maximum consumption and searching ability of C. undecimpunctata were significantly lower than that of CK, C. undecimpunctata‘s 1, 2, 3, 4 instars and adult instantaneous attack rate fell by 0.38%, 7.18%, 2.19%, 16.83% and 1.41%, the handling times required for a head of A. gossypii were extended the 0.002,4 d, 0.001,6 d, 0.000,6 d, 0.000,5 d and 0.000,1 d. The daily maximum consumption decreased by 0.72, 2.52, 7.76, 7.01 and 1.17 heads/dish, respectively. 【Conclusion】 The instantaneous attack rates of C. undecimpunctata of 1-4 instar larva and adult fed on A. gossypii treated with sublethal doses of flonicamid were reduced, the handling time was prolonged to certain degree, and the daily maximum predation amount decreased. Among them, A. gossypii treated with flonicamid LC₅₀ had the most obvious effect on the individual state of C. undecimpunctata.