Department of Plant Protection, Universidade Federal de Santa Maria, Santa Maria, Rio Grande do Sul, Brazil.
J Econ Entomol. 2019 May 22;112(3):1378-1387. doi: 10.1093/jee/toz031.
Soybean looper (SBL), Chrysodeixis includens (Walker) (Lepidoptera: Noctuidae), is an important pest of soybean and cotton in Brazil. The use of insecticides is one of the main control tactics against this pest. To support Integrated Pest Management (IPM) and Insect Resistance Management (IRM) programs, we characterized the susceptibility of Brazilian populations of SBL to insecticides. Field populations were collected from soybean fields during the 2016-2017 and 2017-2018 crop seasons. In the laboratory, late L2/early L3 larvae were exposed to insecticides in diet-overlay or topical bioassays. Field populations of SBL showed high susceptibility to spinetoram (LC50 = 0.074-0.25 μg a.i. per cm2), indoxacarb (LC50 = 0.46-0.94 μg a.i. per cm2), thiodicarb (LC50 = 9.14-36.61 μg a.i. per cm2), chlorantraniliprole (LC50 = 0.15-0.57 μg a.i. per cm2), flubendiamide (LC50 = 0.45-2.01 μg a.i. per cm2), and chlorfenapyr (LC50 = 0.15-0.25 μg a.i. per cm2); the resistance ratios were less than 16-fold. In contrast, SBL populations have reduced susceptibility to lambda-cyhalothrin (LC50 = 3.71-9.54 μg a.i./cm2), methoxyfenozide (LC50 = 0.67-4.23 μg a.i. per cm2), novaluron (LC50 = 27.52-77.63 μg a.i. per cm2), and teflubenzuron (LC50 = 13.41-73.02 μg a.i. per cm2). The resistance ratios relative to a Lab population (susceptible of reference) was up to 38-, 63-, 1,553-, and 5,215-fold, respectively. These high resistance ratios can be associated with resistance evolution. Implications of these findings to IPM and IRM programs are discussed.
大豆食心虫（SBL），Chrysodeixis includens（Walker）（鳞翅目：夜蛾科），是巴西大豆和棉花的重要害虫。使用杀虫剂是防治这种害虫的主要策略之一。为了支持综合虫害管理（IPM）和昆虫抗药性管理（IRM）计划，我们对巴西 SBL 种群对杀虫剂的敏感性进行了特征描述。田间种群是在 2016-2017 和 2017-2018 作物季节从大豆田中采集的。在实验室中，晚期 L2/早期 L3 幼虫在饮食覆盖或局部生物测定中接触杀虫剂。SBL 的田间种群对乙基多杀菌素（LC50=0.074-0.25μg a.i. /cm2）、茚虫威（LC50=0.46-0.94μg a.i. /cm2）、涕灭威（LC50=9.14-36.61μg a.i. /cm2）、氯虫苯甲酰胺（LC50=0.15-0.57μg a.i. /cm2）、氟苯虫酰胺（LC50=0.45-2.01μg a.i. /cm2）和氯氰菊酯（LC50=0.15-0.25μg a.i. /cm2）表现出高敏感性；抗性比值小于 16 倍。相比之下，SBL 种群对高效氯氟氰菊酯（LC50=3.71-9.54μg a.i. /cm2）、甲氧虫酰肼（LC50=0.67-4.23μg a.i. /cm2）、虫螨腈（LC50=27.52-77.63μg a.i. /cm2）和除虫脲（LC50=13.41-73.02μg a.i. /cm2）的敏感性降低。与实验室种群（敏感参考品系）的抗性比值分别高达 38、63、1553 和 5215 倍。这些高抗性比值可能与抗药性进化有关。讨论了这些发现对 IPM 和 IRM 计划的意义。
