Guangdong Engineering Research Center for Modern Eco-agriculture and Circular Agriculture, Guangzhou, China.
Key Laboratory of Agro-Environment in the Tropics, Ministry of Agriculture, South China Agricultural University, Guangzhou, China.
Insect Sci. 2019 Aug;26(4):711-720. doi: 10.1111/1744-7917.12642. Epub 2018 Oct 25.
Herbicides and insecticides are widely used in modern agriculture. It has been reported in various studies that application of insecticides can increase tolerance of herbivorous insects to insecticides. However, limited information exists on susceptibility to insecticides when insects are exposed to herbicides. This study was conducted to investigate the potential impact of the herbicides trifluralin and 2-methyl-4-chlorophenoxyacetic acid sodium salt (MCPA-Na) on the susceptibility of the nocturnal moth Spodoptera litura to the insecticides λ-cyhalothrin, phoxim and bifenthrin. We found that larvae exposed to trifluralin or MCPA-Na became significantly less susceptible to both insecticides than non-exposed control larvae. Herbicide-treated larvae did not show altered growth under the used test conditions. However, heads of herbicide-treated larvae showed increased expression of the acetylcholinesterase genes SlAce1 and SlAce2. Moreover, the fat body and midgut of herbicide-treated larvae displayed elevated expression of detoxification genes (the carboxylesterase gene SlCarE; the glutathione S-transferase genes SlGSTe2 and SlGSTe3; the cytochrome P450 monooxygenase genes CYP6B48, CYP9A40 and CYP321B1). The CYP6B48 gene exhibited highest inducibility. In conclusion, the data of this study suggest that exposure of S. litura larvae to herbicides may stimulate detoxification mechanisms that compromise the efficacy of insecticides.
除草剂和杀虫剂在现代农业中被广泛使用。在各种研究中报告称，使用杀虫剂可以提高草食性昆虫对杀虫剂的耐受性。然而，当昆虫接触除草剂时，对杀虫剂的敏感性的相关信息有限。本研究旨在调查除草剂氟乐灵和 2-甲基-4-氯苯氧乙酸钠盐（MCPA-Na）对夜蛾斜纹夜蛾对杀虫剂 λ-氯氟氰菊酯、辛硫磷和高效氯氟氰菊酯敏感性的潜在影响。我们发现，暴露于氟乐灵或 MCPA-Na 的幼虫对这两种杀虫剂的敏感性明显低于未暴露的对照幼虫。在使用的测试条件下，经除草剂处理的幼虫的生长没有发生变化。然而，经除草剂处理的幼虫的头部显示出乙酰胆碱酯酶基因 SlAce1 和 SlAce2 的表达增加。此外，经除草剂处理的幼虫的脂肪体和中肠显示出解毒基因（羧酸酯酶基因 SlCarE；谷胱甘肽 S-转移酶基因 SlGSTe2 和 SlGSTe3；细胞色素 P450 单加氧酶基因 CYP6B48、CYP9A40 和 CYP321B1）的表达升高。CYP6B48 基因表现出最高的诱导性。总之，本研究的数据表明，斜纹夜蛾幼虫暴露于除草剂可能会刺激解毒机制，从而降低杀虫剂的功效。
