摘  要  【目的】 明确乙嘧酚、戊唑醇、腈菌唑和吡唑醚菌酯4种防治白粉病药剂对加州新小绥螨Neoseiulus californicus (McGregor)的安全系数和捕食功能影响，为协同使用杀菌剂和天敌益螨提供基础依据。【方法】 采用叶盘残毒法测定4种药剂对加州新小绥螨的急性毒性和安全系数，以及评估4种药剂处理后对二斑叶螨Tetranychus urticae Koch各螨态的直接捕食量、功能反应和寻找效应影响。【结果】 4种药剂对加州新小绥螨的急性毒性均为低风险，安全系数依次为戊唑醇（>3 333.333）>乙嘧酚（>631.578）>腈菌唑（563.943）>吡唑醚菌酯（19.464）。在田间最大推荐使用浓度下，4种药剂处理后加州新小绥螨对二斑叶螨各螨态的功能反应均符合Holling Ⅱ模型。乙嘧酚处理后加州新小绥螨对二斑叶螨各螨态的直接捕食量、捕食功能和寻找效应无影响，戊唑醇在较大猎物密度下降低了加州新小绥螨捕食二斑叶螨卵和前若螨量，腈菌唑降低了其捕食卵、前若螨和成螨量，吡唑醚菌酯降低了其捕食各螨态量。戊唑醇、腈菌唑和吡唑醚菌酯对加州新小绥螨的捕食功能产生消极影响，随着处理猎物时间的增加，最大捕食量和捕食能力均表现降低。其中，戊唑醇降低对二斑叶螨卵（21.21%）和前若螨（26.80%）的捕食能力，腈菌唑处理降低对二斑叶螨卵（27.89%）、前若螨（40.06%）和成螨（42.60%）的捕食能力，吡唑醚菌酯处理降低对二斑叶螨卵（30.90%）、幼螨（64.63%）、前若螨（65.26%）、后若螨（40.67%）和成螨（48.91%）的捕食能力。吡唑醚菌酯的寻找效应降低程度最大，其次是腈菌唑和戊唑醇。【结论】 利用加州新小绥螨控制害螨需注意选择性使用防治白粉病杀菌剂，优先建议使用乙嘧酚，少用或注意使用戊唑醇和腈菌唑，慎用吡唑醚菌酯。

Abstract  [Aim]  To determine the effects of four powdery mildew fungicides, ethirimol, tebuconazole, myclobutanil and pyraclostrobine, on the safety coefficient and predation behavior of Neoseiulus californicus (McGregor) (Acari: Phytoseiidae). The findings of this study will establish an experimental foundation for the combined application of fungicides and predatory mites. [Methods]  The acute toxicity and safety coefficient of four fungicides on N. californicus were determined using the leaf disk residual toxicity method. The direct predation, functional response, and search rate of N. californicus on Tetranychus urticae Koch was assessed following treatment with ethirimol, tebuconazole, myclobutanil and pyraclostrobine. [Results]  The acute toxicities of the four fungicides to N. californicus were all low, with tebuconazole, ethirimol, myclobutanil, and pyraclostrobine, having safety coefficients of >3 333.333, >631.578, 563.943 and 19.464, respectively. Following treatment with the four fungicides at the maximum recommended field dose, the functional responses of each N. californicus mite preying on T. urticae remained at Holling’s TypeⅡ. There was no effect of ethirimol treatment on the direct predation amount, predation function, or search rate of N. californicus on T. urticae. At higher prey densities, tebuconazole treatment resulted in reduced eggs and protonymph predation. Myclobutanil treatment reduced predation of eggs, protonymph mites, and adult mites, whereas pyraclostrobine treatment reduced predation of all mite developmental stages. The predation function of N. californicus was negatively affected by the effects of tebuconazole, myclobutanil and pyraclostrobine, which increased prey handling time and decreased the maximum predatory amount and predation capacity. Tebuconazole treatment reduced predation of T. urticae eggs and protonymphs by 21.21% and 26.80%, respectively. Myclobutanil treatment reduced T. urticae egg, protonymph, and adult predation by 27.89%, 40.06%, and 42.60%, respectively. Finally, Pyraclostrobine treatment reduced T. urticae egg, larva, protonymph, deutonymph, and adult predation by 30.90 %, 64.63%, 65.26%, 40.67% and 48.91%, respectively. Pyraclostrobine treatment was the most effective at reducing N. californicus search rate, followed by myclobutanil and tebuconazole. [Conclusion]  Selective use of fungicides to control powdery mildew should be emphasized when using N. californicus to manage T. urticae. Based on the findings of this study we recommend prioritizing the use of ethirimol, while tebuconazole and myclobutanil should be used with caution, and pyraclostrobine should only be used with careful consideration.