Godoy Daniela N, Dallanora Arthur, Pretto Venicius E, Palharini Ramon B, Diniz Luiz H M, Moreira Rafaella P, Reis Alexandre C, Warpechowski Luiz F, Bernardi Oderlei
Department of Plant Protection, Federal University of Santa Maria, Santa Maria, Brazil.
Pest Manag Sci. 2025 Apr;81(4):1829-1839. doi: 10.1002/ps.8580. Epub 2024 Dec 5.
The sunflower looper, Rachiplusia nu (Guenée), evolved resistance to the insecticidal protein Cry1Ac expressed in soybean and emerged as an important soybean pest in Brazil, requiring the application of insecticides for their control. Here, we characterized the susceptibility of Brazilian populations of R. nu to several insecticides and developed diagnostic concentrations for a proactive insect resistance management (IRM) program.
Geographically distinct populations of R. nu from Brazil showed a small amount of variation in susceptibility to 15 growth regulator-, muscle-, nerve- and respiration-action insecticides, presenting resistance levels ≤6.2-fold those of a susceptible population. In contrast, field populations of R. nu showed 11- to 31-fold higher resistance to flubendiamide (muscle-acting) and bifenthrin (nerve-acting) than did the susceptible population, suggesting the presence of low to moderate resistance levels. The diagnostic concentration of each insecticide established in the current study caused >98% mortality against field populations of R. nu.
In general, field populations of R. nu from Brazil showed a small amount of variation in susceptibility and low levels of resistance to major insecticides commonly used for their control. The estimated diagnostic concentrations defined here are recommended for use in a proactive IRM program for monitoring the resistance of R. nu to insecticides. © 2024 Society of Chemical Industry.
向日葵夜蛾（Rachiplusia nu (Guenée)）对大豆中表达的杀虫蛋白Cry1Ac产生了抗性，并在巴西成为一种重要的大豆害虫，需要使用杀虫剂来进行防治。在此，我们对巴西的向日葵夜蛾种群对几种杀虫剂的敏感性进行了表征，并制定了诊断浓度，以开展积极的抗虫管理（IRM）计划。
来自巴西的地理上不同的向日葵夜蛾种群对15种作用于生长调节剂、肌肉、神经和呼吸的杀虫剂的敏感性表现出少量差异，抗性水平≤敏感种群的6.2倍。相比之下，向日葵夜蛾的田间种群对氟苯虫酰胺（作用于肌肉）和联苯菊酯（作用于神经）的抗性比敏感种群高11至31倍，表明存在低至中等抗性水平。本研究确定的每种杀虫剂的诊断浓度对向日葵夜蛾田间种群的致死率>98%。
总体而言，巴西的向日葵夜蛾田间种群对常用的主要杀虫剂的敏感性差异较小，抗性水平较低。建议将此处确定的估计诊断浓度用于积极的IRM计划，以监测向日葵夜蛾对杀虫剂的抗性。© 2024化学工业协会。
