Haddi Khalid, Mendonça Larine P, Dos Santos Milaine F, Guedes Raul Narciso C, Oliveira Eugênio E
Science without Border Associate Researcher, Programa de Pós-Graduação em Entomologia, Universidade Federal de Viçosa, Viçosa, MG 36570-000, Brasil. Departamento de Entomologia, Universidade Federal de Viçosa, Viçosa, MG 36570-000, Brasil.
Departamento de Entomologia, Universidade Federal de Viçosa, Viçosa, MG 36570-000, Brasil.
J Econ Entomol. 2015 Feb;108(1):362-9. doi: 10.1093/jee/tou049. Epub 2015 Jan 24.
The control of the most important pest of stored maize, the weevil Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae), is mainly achieved with the use of pyrethroid insecticides. However, the intensive use of these compounds has led to the selection of resistant populations and has compromised the control efficacy of this insect pest. Here, the toxicity of indoxacarb for a potential use in the control of S. zeamais was assessed on 13 Brazilian populations. Concentration-mortality bioassays, in the presence of synergists (piperonyl butoxide, triphenyl phosphate, and diethyl maleate), were used to assess potential metabolic-based indoxacarb resistance mechanisms. We also assessed the behavioral (locomotory) responses of these populations to indoxacarb exposure. The results showed significant differences between the populations (LD50 values ranged from 0.06 to 13.99 mg a.i/kg of grains), resulting in resistance ratios of >200-fold between the least (Canarana-MT) and the most (Espirito Santo do Pinhal-SP) susceptible populations. The results obtained with synergized indoxacarb suggest the involvement of esterases and glutathione-S-transferases on indoxacarb action, and also suggest the involvement of cytochrome P450-dependent monooxygenases as a potential indoxacarb resistance mechanism in Brazilian populations of S. zeamais. Although indoxacarb-induced behavioral avoidance varied among populations, some resistant populations (e.g., Canarana-MT) were able to reduce exposure to indoxacarb by spending more time in the nontreated areas. Collectively, our findings indicate that the behavioral (locomotory) and physiological responses of these insects may compromise the control efficacy of oxadiazine insecticides (e.g., indoxacarb) in Brazilian populations of S. zeamais.
储存玉米最重要的害虫玉米象Sitophilus zeamais Motschulsky（鞘翅目：象甲科）的防治主要通过使用拟除虫菊酯类杀虫剂来实现。然而，这些化合物的大量使用导致了抗性种群的产生，并损害了这种害虫的防治效果。在此，评估了茚虫威对巴西13个种群的玉米象的潜在防治效果。在增效剂（胡椒基丁醚、磷酸三苯酯和顺丁烯二酸二乙酯）存在的情况下，进行浓度-死亡率生物测定，以评估基于代谢的茚虫威抗性机制。我们还评估了这些种群对茚虫威暴露的行为（运动）反应。结果表明种群之间存在显著差异（半数致死剂量值范围为0.06至13.99毫克有效成分/千克谷物），导致最敏感种群（卡纳拉-马托格罗索州）和最不敏感种群（圣埃斯皮里图州皮尼亚尔-圣保罗州）之间的抗性比率超过200倍。增效茚虫威的实验结果表明酯酶和谷胱甘肽-S-转移酶参与了茚虫威的作用，也表明细胞色素P450依赖的单加氧酶作为巴西玉米象种群中潜在的茚虫威抗性机制。尽管茚虫威引起的行为回避在种群间有所不同，但一些抗性种群（如卡纳拉-马托格罗索州）能够通过在未处理区域花费更多时间来减少对茚虫威的接触。总体而言，我们的研究结果表明，这些昆虫的行为（运动）和生理反应可能会损害恶二嗪类杀虫剂（如茚虫威）对巴西玉米象种群的防治效果。
