Hubhachen Zhaorigetu, Pointon Henry, Perkins Jacquelyn A, Van Timmeren Steven, Pittendrigh Barry, Isaacs Rufus
Department of Entomology, Michigan State University, East Lansing, MI 48824, USA.
Department of Entomology, Purdue University, 901 West State Street, West Lafayette, IN 47907, USA.
J Econ Entomol. 2022 Dec 14;115(6):2020-2028. doi: 10.1093/jee/toac155.
Vinegar flies are vectors of pathogens causing fruit rots of grapes, so control of these insects is important for preventing vineyard yield loss. Recent outbreaks of sour rots may be linked to greater challenges controlling vinegar flies, so we investigated the insecticide susceptibility of populations collected from commercial vineyards across Michigan. We first determined the discriminating concentration for phosmet, malathion, methomyl, and zeta-cypermethrin using a laboratory susceptible (Canton-S) strain of D. melanogaster females. The discriminating concentrations were determined as 252.08, 2.58, 0.96, and 1.68 ppm of the four insecticides, respectively. These concentrations were first tested in 2020 against populations from the two major counties for grape production. In 2021, we expanded monitoring to twenty-three populations collected from vineyards across six counties. All populations had significantly lower sensitivity to all four insecticides compared with Canton-S strain, with up to 98.8% lower mortality for phosmet. The LC50, LC90, and LC99 values of the four insecticides for the two populations tested in 2020 were 7-1,157-fold higher than the Canton-S strain. For the twenty-three populations collected in 2021, mortality ranged from 56.3 to 100% when the flies were screened using a 10x concentration of the discriminating concentration of the insecticides, whereas it ranged from 82.4 to 100% when the flies were screened using a 20x concentration. Our results suggest variable levels of resistance to insecticides from multiple chemical classes in D. melanogaster populations in Michigan vineyards, highlighting the need to implement integrated sour rot management approaches that are less dependent on insecticides for control of this species.
果蝇是导致葡萄果实腐烂的病原体的传播媒介，因此控制这些昆虫对于防止葡萄园产量损失很重要。最近酸腐病的爆发可能与控制果蝇面临的更大挑战有关，所以我们调查了从密歇根州各地商业葡萄园采集的果蝇种群对杀虫剂的敏感性。我们首先使用实验室敏感的（坎顿-S）黑腹果蝇雌性品系确定了谷硫磷、马拉硫磷、灭多威和高效氯氰菊酯的区分浓度。这四种杀虫剂的区分浓度分别确定为252.08、2.58、0.96和1.68 ppm。这些浓度在2020年首次针对葡萄生产的两个主要县的种群进行了测试。2021年，我们将监测范围扩大到从六个县的葡萄园采集的23个种群。与坎顿-S品系相比，所有种群对这四种杀虫剂的敏感性均显著降低，谷硫磷的死亡率降低了98.8%。2020年测试的两个种群对这四种杀虫剂的LC50、LC90和LC99值比坎顿-S品系高7至1157倍。对于2021年采集的23个种群，当使用杀虫剂区分浓度的10倍浓度筛选果蝇时，死亡率在56.3%至100%之间，而当使用20倍浓度筛选果蝇时，死亡率在82.4%至100%之间。我们的结果表明，密歇根州葡萄园的黑腹果蝇种群对多种化学类别的杀虫剂存在不同程度的抗性，这突出表明需要实施综合酸腐病管理方法，减少对杀虫剂控制该物种的依赖。
