Du Yuzhe, Zhu Yucheng, Scheibener Shane, Portilla Maribel
Southern Insect Management Research Unit, Agriculture Research Service, United States Department of Agriculture, 141 Experiment Station Road, Stoneville, MS 38776, USA.
Pollinator Health in Southern Crop Research Service, Agriculture Research Service, United States Department of Agriculture, 141 Experiment Station Road, Stoneville, MS 38776, USA.
Insects. 2023 Sep 13;14(9):761. doi: 10.3390/insects14090761.
Over the past several decades, the extensive use of pyrethroids has led to the development of resistance in many insect populations, including the economically damaging pest tarnished plant bug (TPB), on cotton. To manage TPB resistance, several commercially formulated pyrethroid-containing binary mixtures, in combination with neonicotinoids or avermectin are recommended for TPB control and resistance management in the mid-South USA. This study aimed to evaluate the toxicity and resistance risks of four formulated pyrethroid-containing binary mixtures (Endigo, Leverage, Athena, and Hero) on one susceptible and two resistant TPB populations, which were field-collected in July (Field-R1) and October (Field-R2), respectively. Based on LC values, both resistant TPB populations displayed variable tolerance to the four binary mixtures, with Hero showing the highest resistance and Athena the lowest. Notably, the Field-R2 exhibited 1.5-3-fold higher resistance compared to the Field-R1 for all four binary insecticides. Moreover, both resistant TPB populations demonstrated significantly higher resistance ratios towards Hero and Leverage compared to their corresponding individual pyrethroid, while Endigo and Athena showed similar or lower resistance. This study also utilized the calculated additive index (AI) and co-toxicity coefficient (CTC) analysis, which revealed that the two individual components in Leverage exhibited antagonist effects against the two resistant TPB populations. In contrast, the two individual components in Endigo, Hero, and Athena displayed synergistic interactions. Considering that Hero is a mixture of two pyrethroids that can enhance the development of TPB resistance, our findings suggest that Endigo and Athena are likely superior products for slowing down resistance development in TPB populations. This study provides valuable insight for selecting the most effective mixtures to achieve better TPB control through synergistic toxicity analysis, while simultaneously reducing economic and environmental risks associated with resistance development in the insect pest.
在过去几十年中，拟除虫菊酯的广泛使用导致许多昆虫种群产生了抗药性，包括对棉花造成经济损害的害虫牧草盲蝽。为了应对牧草盲蝽的抗药性问题，在美国中南部地区，推荐使用几种商业化配方的含拟除虫菊酯二元混合物，并与新烟碱类或阿维菌素联合使用，以控制牧草盲蝽并管理其抗药性。本研究旨在评估四种配方含拟除虫菊酯二元混合物（Endigo、Leverage、Athena和Hero）对一个敏感和两个抗性牧草盲蝽种群的毒性和抗药性风险，这两个抗性种群分别于7月（田间-R1）和10月（田间-R2）采自田间。基于半数致死浓度值，两个抗性牧草盲蝽种群对这四种二元混合物表现出不同程度的耐受性，其中Hero的抗性最高，Athena的抗性最低。值得注意的是，对于所有四种二元杀虫剂，田间-R2的抗性比田间-R1高1.5至3倍。此外，与相应的单一拟除虫菊酯相比，两个抗性牧草盲蝽种群对Hero和Leverage的抗性比率显著更高，而Endigo和Athena的抗性相似或更低。本研究还利用计算得出的相加指数（AI）和共毒系数（CTC）分析，结果表明Leverage中的两种单一成分对两个抗性牧草盲蝽种群表现出拮抗作用。相比之下，Endigo、Hero和Athena中的两种单一成分表现出协同作用。鉴于Hero是两种拟除虫菊酯的混合物，可能会加速牧草盲蝽抗药性的发展，我们的研究结果表明，Endigo和Athena可能是减缓牧草盲蝽种群抗药性发展的更优产品。本研究通过协同毒性分析为选择最有效的混合物以实现更好的牧草盲蝽防治提供了有价值的见解，同时降低了与害虫抗药性发展相关的经济和环境风险。
