Kim Dae-Yun, Hii Jeffrey, Chareonviriyaphap Theeraphap
Department of Entomology, Faculty of Agriculture, Kasetsart University, Bangkok 10900, Thailand.
Research and Lifelong Learning Center for Urban and Environmental Entomology, Institute for Advanced Studies, Kasetsart University, Bangkok 10900, Thailand.
Insects. 2024 Aug 15;15(8):616. doi: 10.3390/insects15080616.
Increasing temperature can enhance the geographical spread and behavior of disease vector mosquitoes, exposing vulnerable populations to -borne viruses and infections. To address this risk, cost-effective and sustained intervention vector control tools are required, such as volatile pyrethroid spatial repellents. This study used a high-throughput screening system toxicity bioassay to determine the discriminating concentrations of transfluthrin-treated filter papers with variable air-drying times exposed to pyrethroid-susceptible mosquitoes. At the highest transfluthrin concentration (0.01706%), a significant reduction in mosquito mortality was observed in filter papers air-dried for 24 h compared to those air-dried for 1 h (odds ratio = 0.390, < 0.001, 95% confidence interval: 0.23-0.66). Conversely, no significant difference in mortality was found between filter papers air-dried for 1 h and those air-dried for 12 h (odds ratio = 0.646, = 0.107, 95% confidence interval: 0.38-1.10). The discriminating concentration was 2.8-fold higher for transfluthrin-treated filter papers air-dried for 24 h than it was for papers air-dried for 1 h, and it increased 5-fold from 1 h to 336 h of air-drying. These results show that the optimal air-drying period of transfluthrin-treated filter paper is critical, as higher discriminating concentration values may lead to underestimations of insecticide resistance. The instability of transfluthrin-treated papers necessitates the use of the World Health Organization (WHO) bottle bioassay, which is the preferred method for determining mosquito susceptibility to volatile insecticides.
气温升高会增强病媒蚊子的地理扩散和活动能力，使易感人群面临虫媒病毒和感染风险。为应对这一风险，需要成本效益高且可持续的病媒控制工具，如拟除虫菊酯类空间驱避剂。本研究采用高通量筛选系统毒性生物测定法，以确定在不同风干时间下，经甲氧苄氟菊酯处理的滤纸对拟除虫菊酯敏感蚊子的区分浓度。在最高甲氧苄氟菊酯浓度（0.01706%）下，与风干1小时的滤纸相比，风干24小时的滤纸对蚊子死亡率有显著降低（优势比 = 0.390，< 0.001，95%置信区间：0.23 - 0.66）。相反，风干1小时和12小时的滤纸之间死亡率无显著差异（优势比 = 0.646，= 0.107，95%置信区间：0.38 - 1.10）。经甲氧苄氟菊酯处理的滤纸，风干24小时的区分浓度比风干1小时的高2.8倍，且从1小时风干至336小时，区分浓度增加了5倍。这些结果表明，经甲氧苄氟菊酯处理的滤纸的最佳风干时间至关重要，因为较高的区分浓度值可能导致对杀虫剂抗性的低估。甲氧苄氟菊酯处理过的滤纸的不稳定性使得有必要使用世界卫生组织（WHO）的药瓶生物测定法，这是确定蚊子对挥发性杀虫剂易感性的首选方法。
