棉铃虫（Spodoptera littoralis （Boisd.））与甲氨基阿维菌素苯甲酸盐和氟虫腈相比，其联合作用相关的生化变化。

Biochemical alterations in cotton leafworm, Spodoptera littoralis (Boisd.) related to emamectin benzoate and fipronil compared to their joint action.

机构信息

Pesticide Chemistry and Technology Department, Faculty of Agriculture (Elshatby), Alexandria University, Alexandria, Egypt.

Central Agricultural Pesticide Laboratory, Agricultural Research Center, Egypt.

出版信息

Pestic Biochem Physiol. 2023 Aug;194:105505. doi: 10.1016/j.pestbp.2023.105505. Epub 2023 Jun 22.

DOI:10.1016/j.pestbp.2023.105505

PMID:37532359

Abstract

Cotton leafworm, Spodoptera littoralis (Boisduval), is one of the major destructive pests of ornamental, industrial, and vegetable crops. The efficacy of technical emamectin benzoate (EMB) and fipronil (FPR) was assessed against the 4 larval instar using leaf-dip bioassay method. EMB was more efficient than FPR based on 96 h LC values of 0.004 and 0.023 μg/ml, respectively. Joint toxic action of the dual exposure in sequence with time interval 24 h and in mix were evaluated at LC:LC, LC:LC and LC:LC after 96 h posttreatment, as well. Their impacts on detoxification enzymes, esterases (ESTs); alkaline phosphatase (ALP); and glutathione S-transferase (GST) as well as acetylcholine esterase (AChE) were also determined. The sequential exposure of EMB after FPR (S1) produced antagonism, potentiation, and potentiation effects, respectively while sequential exposure of FPR after EMB (S2) interacted as addition, potentiation, and potentiation respectively. The rest of binary mixtures (Mix) revealed antagonistic effect regardless of concentration. Orthogonal contrast analysis showed that the highest elevations of AChE, α-EST, β- EST and ALP enzymes were obtained from Mix at LC:LC (181.6%, 288.4, 229.2 and 460.9%, respectively), LC:LC (131.5%, 252.8, 205.60 and 252.0, respectively) and LC:LC (106.6%, 215.6%, 201.8% and 170.0%, respectively). Differently, the greatest elevation of GST activity (157.7%) resulted from S1 at LC:LC, while it was significantly lower at LC:LC and LC:LC as well as Mix and S2 at all concentrations than corresponding concentrations of FPR. These findings shed some light on the role of GST in FPR toxicity and clarified the risk of these dual exposures in elevating detoxification enzymes dangerously compared to their individual insecticides. These dual exposures should be carefully handled. Although rotational exposure at low concentrations may enhance performance and mitigate resistance risk, rotational exposure at high concentrations and Mix may indirectly contribute to the evolution of cross-resistance to other insecticides.

摘要

棉铃虫（Spodoptera littoralis）是一种重要的农业害虫，主要危害观赏植物、工业作物和蔬菜作物。本研究采用浸叶法评估了技术埃玛菌素苯甲酸盐（EMB）和氟虫腈（FPR）对 4 龄幼虫的药效。96 h 后，LC 值分别为 0.004 μg/ml 和 0.023 μg/ml，EMB 的效果优于 FPR。采用时间间隔 24 h 的顺序双重暴露以及混合暴露的方法，评估了 96 h 后 LC:LC、LC:LC 和 LC:LC 下的联合毒性作用。还测定了它们对解毒酶、酯酶（ESTs）；碱性磷酸酶（ALP）；谷胱甘肽 S-转移酶（GST）和乙酰胆碱酯酶（AChE）的影响。先暴露于 EMB 后暴露于 FPR（S1）产生拮抗、增效和增效作用，而先暴露于 FPR 后暴露于 EMB（S2）则表现为相加、增效和增效作用。无论浓度如何，其余的二元混合物（Mix）均表现出拮抗作用。正交对比分析表明，在 LC:LC（181.6%、288.4%、229.2%和 460.9%）、LC:LC（131.5%、252.8%、205.60%和 252.0%）和 LC:LC（106.6%、215.6%、201.8%和 170.0%）处，Mix 中 AChE、α-EST、β-EST 和 ALP 酶的活性最高。相反，LC:LC 时 S1 的 GST 活性（157.7%）最高，而 LC:LC 和 LC:LC 以及 Mix 和 S2 的 GST 活性均显著低于相应浓度的 FPR。这些发现揭示了 GST 在 FPR 毒性中的作用，并阐明了与单独使用杀虫剂相比，这些双重暴露会增加解毒酶的危险，从而增加抗药性的风险。这些双重暴露应谨慎处理。虽然低浓度的轮换暴露可能会提高性能并降低抗药性风险，但高浓度的轮换暴露和混合暴露可能会间接导致对其他杀虫剂产生交叉抗药性的演变。