Ditillo J L, Kennedy G G, Walgenbach J F
Department of Entomology & Plant Pathology, North Carolina State University, Raleigh, NC 27695 (
Department of Entomology & Plant Pathology, North Carolina State University, Mountain Horticultural Crops Research & Extension Center, Mills River, NC 28759 (
J Econ Entomol. 2016 Dec;109(6):2298-2308. doi: 10.1093/jee/tow234. Epub 2016 Oct 23.
The twospotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae), is an important pest of tomatoes in North Carolina. Resident populations of the predatory mite Phytoseiulus persimilis have recently been detected on field-grown tomatoes in central North Carolina, and potentially can be a useful biological control agent against T. urticae Laboratory bioassays were used to assess lethal and reproductive effects of 10 insecticides and five fungicides commonly used in commercial tomato production (chlorantraniliprole, spinetoram, permethrin, imidacloprid, dimethoate, dinotefuran, thiamethoxam, bifenthrin, fenpropathrin, lambda-cyhalothrin, azoxystrobin, chlorothalonil, boscalid, cyazofamid, and mancozeb) on P. persimilis adult females and eggs. Insecticides were tested using concentrations equivalent to 1×, 0.5×, and 0.1× of the recommended field rates. Fungicides were tested at the 1× rate only. Dimethoate strongly impacted P. persimilis with high adult mortality, reduced fecundity, and reduced hatch of eggs laid by treated adults, particularly at high concentrations. The pyrethroids lambda-cyhalothrin, bifenthrin, and fenpropathrin were associated with repellency and reproductive effects at high concentrations. Bifenthrin additionally caused increased mortality at high concentrations. Chlorantraniliprole, dinotefuran, and permethrin did not significantly affect mortality or reproduction. Imidacloprid significantly reduced fecundity and egg viability, but was not lethal to adult P. persimilis Thiamethoxam negatively impacted fecundity at the 1× rate. There were no negative effects associated with fungicide exposure with the exception of mancozeb, which impacted fecundity. Field trials were conducted to explore the in vivo impacts of screened insecticides on P. persimilis populations in the field. Field trials supported the incompatibility of dimethoate with P. persimilis populations.
二斑叶螨，即土耳其斯坦叶螨科赫（蜱螨目：叶螨科），是北卡罗来纳州番茄的一种重要害虫。最近在北卡罗来纳州中部种植于田间的番茄上检测到了捕食螨加州新小绥螨的定居种群，其有可能成为防治二斑叶螨的一种有用的生物防治剂。实验室生物测定用于评估10种杀虫剂和5种商业番茄生产中常用的杀菌剂（氯虫苯甲酰胺、多杀霉素、氯菊酯、吡虫啉、乐果、呋虫胺、噻虫嗪、联苯菊酯、甲氰菊酯、高效氯氟氰菊酯、嘧菌酯、百菌清、啶酰菌胺、氰霜唑和代森锰锌）对加州新小绥螨成年雌螨和卵的致死及繁殖影响。杀虫剂使用相当于推荐田间施用量1倍、0.5倍和0.1倍的浓度进行测试。杀菌剂仅以1倍剂量进行测试。乐果对加州新小绥螨有强烈影响，导致成年螨死亡率高、繁殖力降低以及经处理的成年螨所产卵的孵化率降低，尤其是在高浓度时。拟除虫菊酯类的高效氯氟氰菊酯、联苯菊酯和甲氰菊酯在高浓度时与驱避和繁殖效应有关。联苯菊酯在高浓度时还导致死亡率增加。氯虫苯甲酰胺、呋虫胺和氯菊酯对死亡率或繁殖没有显著影响。吡虫啉显著降低了繁殖力和卵的活力，但对成年加州新小绥螨不具有致死性。噻虫嗪在1倍剂量时对繁殖力有负面影响。除了影响繁殖力的代森锰锌外，杀菌剂暴露没有产生负面影响。进行了田间试验以探究筛选出的杀虫剂对田间加州新小绥螨种群的体内影响。田间试验证实乐果与加州新小绥螨种群不相容。
