Leong Xin-Yeng, Singham G Veera, Shu-Chien Alexander Chong, Doggett Stephen L, Lee Chow-Yang
Urban Entomology Laboratory, Vector Control Research Unit, School of Biological Sciences, Universiti Sains Malaysia, Minden 11800, Penang, Malaysia.
Centre for Chemical Biology, Universiti Sains Malaysia, Bayan Lepas 11900, Penang, Malaysia.
Insects. 2020 Sep 18;11(9):640. doi: 10.3390/insects11090640.
We evaluated the influences of insecticide exposure time and mortality assessment intervals on the bioassay results of three insecticide-resistant tropical bed bug (F.) populations (Madam Mo, Tanjong Tokong, and Green Lane). This was achieved using the surface contact method and tested with six commercial insecticide products: Tandem, Temprid SC, Pesguard FG161, Sumithrin, Sumithion, and Phantom applied at label rate on glass petri dishes. Six exposure times (5 min, 10 min, 30 min, 1 h, 4 h, and continuous exposure for 4 or 14 days for Phantom) were tested. A susceptible common bed bug L. strain (Monheim) was used as the reference strain as no susceptible strain exists. In treatment with Temprid SC, the Tanjong Tokong strain showed significantly higher KT values at 5, 10, and 30 min exposures than 1 h, 4 h, and continuous exposures. When all resistant populations were evaluated at continuous exposure to Sumithion, they demonstrated moderate resistance levels (RR ranged from 6.0 to 7.9), while KT and KT of other shorter exposure times failed to be generated due to low knockdown rate. Higher mortalities were observed in Tanjong Tokong and Green Lane strains when tested at longer exposure times with Temprid SC, Pesguard FG161, Sumithrin, Sumithion, and Phantom. Better killing effect was observed in the treatment with Temprid SC (Tanjong Tokong and Green Lane strains), Pesguard FG161 (Tanjong Tokong and Green Lane strains), Sumithrin (all strains), Sumithion (all strains), and Phantom (all strains tested) at longer mortality assessment intervals. We demonstrated that insecticide exposure time and mortality assessment interval could potentially affect outcomes of product performance evaluations, resulting in underestimation or overestimation of insecticide resistance levels in field populations.
我们评估了杀虫剂暴露时间和死亡率评估间隔对三种抗杀虫剂热带臭虫（F.）种群（摩摩夫人、丹绒东孔和绿巷）生物测定结果的影响。这是通过表面接触法实现的，并使用六种市售杀虫剂产品进行测试：Tandem、Temprid SC、Pesguard FG161、胺菊酯、杀螟硫磷和Phantom，以标签推荐剂量施用于玻璃培养皿上。测试了六种暴露时间（5分钟、10分钟、30分钟、1小时、4小时，以及Phantom连续暴露4天或14天）。由于不存在敏感品系，因此使用敏感的普通臭虫L.品系（蒙海姆）作为参考品系。在用Temprid SC处理时，丹绒东孔品系在暴露5分钟、10分钟和30分钟时的击倒时间（KT）值显著高于暴露1小时、4小时和连续暴露时的值。当对所有抗性种群进行杀螟硫磷连续暴露评估时，它们表现出中等抗性水平（抗性比率RR范围为6.0至7.9），而由于击倒率低，其他较短暴露时间的KT和击倒时间（KT）未能得出。在用Temprid SC、Pesguard FG161、胺菊酯、杀螟硫磷和Phantom进行较长暴露时间测试时，丹绒东孔和绿巷品系的死亡率更高。在较长的死亡率评估间隔下，用Temprid SC（丹绒东孔和绿巷品系）Pesguard FG161（丹绒东孔和绿巷品系）、胺菊酯（所有品系）、杀螟硫磷（所有品系）和Phantom（所有测试品系）处理时观察到更好的杀灭效果。我们证明，杀虫剂暴露时间和死亡率评估间隔可能会影响产品性能评估的结果，从而导致对田间种群杀虫剂抗性水平的低估或高估。
