Institute of Agricultural Sciences, University of the Punjab, Lahore, Pakistan.
Chemosphere. 2020 Oct;257:127167. doi: 10.1016/j.chemosphere.2020.127167. Epub 2020 May 27.
Resistance to commonly used grain protectants and fumigants in stored product insect pests necessitates the need to explore alternative substances. Indoxacarb is a reduced-risk oxadiazine insecticide that is generally used in field crops, but there are limited reports of its susceptibility in stored insect pests. The objective of this study was to determine susceptibility to indoxacarb in laboratory and field strains of five major stored product insects: Rhyzopertha dominica (Fabricius), Sitophilus zeamais (Motschulsky), S. oryzae (Linnaeus), Tribolium castaneum (Herbst), and Oryzaephilus surinamensis (L.), using dose-mortality bioassays on wheat grains. In most of the cases, the susceptibility of laboratory strains of all the studied pests were significantly higher than the corresponding field strains. The LD and LD values (mg a.i./kg of grains) of field strains ranged from 0.13 to 0.38, and 3.44 to 24.76, respectively (for R. dominica), 0.26 to 0.55, and 5.26 to 19.37, respectively (for S. oryzae), 0.41 to 1.01, and 13.11 to 22.46, respectively (for S. zeamais), 0.67 to 1.37, and 15.43 to 43.44, respectively (for T. castaneum), and 0.52 to 0.92, and 18.06 to 61.63, respectively (for O. surinamensis). Synergism bioassays implementing piperonyl butoxide or S,S,S-tributyl phosphorotrithioate along with indoxacarb on selected field strains revealed enhanced susceptibility to indoxacarb. The study demonstrates relative susceptibility to indoxacarb in major stored product insects. Synergism results support the probability of metabolic-based mechanisms responsible for mitigating indoxacarb toxicity. The results might be helpful for monitoring future variation in susceptibility to indoxacarb in the selected insect species and for setting field rates.
抗常见谷物保护剂和熏蒸剂已成为储粮害虫防治的迫切需要，因此需要探索替代物质。茚虫威是一种低风险的噁二嗪杀虫剂，通常用于田间作物，但有关其在储粮害虫中敏感性的报道有限。本研究旨在使用小麦籽粒剂量 - 死亡率生物测定法，确定实验室和田间 5 种主要储粮害虫（暗黑鳃金龟、玉米象、米象、赤拟谷盗和锯谷盗）对茚虫威的敏感性。在大多数情况下，所有研究害虫的实验室种群的敏感性明显高于相应的田间种群。田间种群的 LD 和 LD 值（mg a.i./kg 谷物）范围分别为 0.13-0.38 和 3.44-24.76（暗黑鳃金龟）、0.26-0.55 和 5.26-19.37（米象）、0.41-1.01 和 13.11-22.46（玉米象）、0.67-1.37 和 15.43-43.44（赤拟谷盗）、0.52-0.92 和 18.06-61.63（锯谷盗）。对选定的田间种群实施增效生物测定，用增效醚或 S,S,S-三丁基膦酸三硫酯与茚虫威共同作用，结果显示对茚虫威的敏感性增强。该研究表明主要储粮害虫对茚虫威相对敏感。增效作用的结果支持代谢解毒机制负责降低茚虫威毒性的可能性。这些结果可能有助于监测所选昆虫物种对茚虫威敏感性的未来变化，并为田间施用量设定提供参考。
