The tobacco budworm, Chloridea (Heliothis) virescens (F.), has evolved resistance to numerous insecticides in the field. In tobacco, chlorantraniliprole can be applied as either a preventative systemic soil application at or near transplant, or a foliar application timed to current treatment thresholds. With a novel mode of action chlorantraniliprole provides an option for rotation with other insecticides to reduce the probability of insecticide resistance development. However, specific usage patterns in tobacco have the potential to increase the risk of resistance development to this insecticide. In particular, soil applied treatments may expose C. virescens to sublethal concentrations of the insecticide. We studied chlorantraniliprole susceptibility in nine field populations and one laboratory strain of C. virescens using a diet incorporation bioassay. Mortality was measured at 7, 10, and 14 d after exposure. Our results demonstrated that bioassays should be evaluated at 14 d after exposure to optimize interpretation of the dose–response due to the antifeeding properties of chlorantraniliprole. We observed low variation within field-collected populations. Field populations were as susceptible as the laboratory strain; the resistance ratio at the 14-d evaluation for field-collected populations ranged from 1.01 to 1.05. A discriminating dose of 0.117, 0.080, and 0.070 μg a.i./g diet could be used at 7, 10, and 14 d, respectively. Larval growth varied between field populations. Two field populations continued growing on diet containing chlorantraniliprole and differed in size from the laboratory and other populations. Further evaluation of growth inhibition will be necessary.

中文翻译：

---

从烤烟到氯虫苯甲酰胺对北卡罗来纳州绿藻 (Heliothis) virescens (Lepidoptera: Noctuidae) 种群的易感性

烟草芽虫 Chloridea (Heliothis) virescens (F.) 在田间已进化出对多种杀虫剂的抗性。在烟草中，氯虫苯甲酰胺可在移植时或移植附近作为预防性系统性土壤施用，或根据当前处理阈值进行叶面施用。氯虫苯甲酰胺具有一种新的作用方式，可以与其他杀虫剂轮换使用，以减少对杀虫剂产生抗药性的可能性。然而，烟草中的特定使用模式有可能增加对这种杀虫剂产生抗药性的风险。特别是，土壤施用处理可能会使 C. virescens 暴露于亚致死浓度的杀虫剂。我们研究了 9 个田间种群和 1 个实验室 C 菌株对氯虫苯甲酰胺的敏感性。virescens 使用饮食掺入生物测定法。在暴露后 7、10 和 14 天测量死亡率。我们的结果表明，由于氯虫苯甲酰胺的拒食特性，应在暴露后 14 天评估生物测定以优化剂量反应的解释。我们观察到在现场收集的种群中变化很小。田间种群与实验室菌株一样易感；田间采集种群在 14 天评价时的抗性比在 1.01 到 1.05 之间。可分别在第 7、10 和 14 天使用 0.117、0.080 和 0.070 μg ai/g 饮食的区别剂量。田间种群之间的幼虫生长不同。两个田间种群在含有氯虫苯甲酰胺的饮食中继续生长，其大小与实验室和其他种群不同。