氰氟虫腙对草地贪夜蛾的毒力与田间防效

【目的】本研究旨在明确氰氟虫腙对草地贪夜蛾Spodoptera frugiperda幼虫的毒力水平和田间防治效果，为科学使用氰氟虫腙防治草地贪夜蛾提供参考依据。【方法】采用饲料混毒法在室内测定了氰氟虫腙与4种常用杀虫剂甲维盐、氯虫苯甲酰胺、虱螨脲和茚虫威对草地贪夜蛾3和6龄幼虫的致死中浓度(LC₅₀)及LC₉₀值，以及LC₉₀浓度的这些杀虫剂对3龄幼虫的致死中时(medium lethal time, LT₅₀)值。采用人工喷雾方法测定了玉米田中22%氰氟虫腙悬浮剂(6.6 g/667 m²)、22%氰氟虫腙悬浮剂(17.6 g/667 m²)、5.7%甲维盐水分散剂(1 g/667 m²)和150 g/L茚虫威悬浮剂(2 g/667 m²)对草地贪夜蛾幼虫的防效。【结果】室内生测结果显示，供试的5种杀虫剂中氰氟虫腙对草地贪夜蛾3和6龄幼虫均具有较高的毒力，其LC₅₀值分别为2.64和4.3...

Toxicity and field efficacy of metaflumizone against the fall armyworm,Spodoptera frugiperda(Lepidoptera: Noctuidae)#br#

【Aim】 This study aims to determine the toxicity level and field control efficacy of metaflumizone against the larval fall armyworm, Spodoptera frugiperda, and to provide a reference for scientific use of metaflumizone in the control of S. frugiperda. 【Methods】 The median lethal concentration (LC₅₀) and LC₉₀ values of metaflumizone and four commonly used insecticides including emamectin benzoate, chlorantraniliprole, lufenuron and indoxacarb against the 3rd and 6th instar larvae of S. frugiperda and the medium lethal time (LT₅₀) values of these insecticides at the concentration of LC₉₀ against the 3rd instar larvae were determined in the laboratory with diet-incorporated method. Simultaneously, the control efficacies of 22% metaflumizone suspension concentrate(6.6 g/667 m²), 22% metaflumizone suspension concentrate (17.6 g/667 m²), 5.7% emamectin benzoate water dispersant (1 g/667 m²), and 150 g/L indoxacarb suspension concentrate (2 g/667 m²) against S. frugiperda larvae were determined in corn field by artificial spray approach. 【Results】 Laboratory bioassay results revealed that among the tested five insecticides metaflumizone showed higher toxicity to the 3rd and 6th instar larvae of S. frugiperda, with the LC₅₀ values of 2.64 and 4.36 mg/kg, respectively, and its toxicity to the 6th instar larvae of S. frugiperda was only lower than that of emamectin benzoate. The LT₅₀ value of metaflumizone at the concentration of LC₉₀ against the 3rd instar larvae of S. frugiperda was 11.98 h, comparable to that of indoxacarb (11.50 h) and lower than those of chlorantraniliprole, emamectin benzoate and lufenuron (17.20, 23.40, and 39.24 h, respectively). Field efficacy test showed that 22% metaflumizone suspension concentrate at the application rate of 17.6 g/667 m² had an excellent control efficacy against S. frugiperda larvae, with the corrected control efficacies of 69.97%, 78.98% and 82.86% at 1, 3 and 7 d after application, respectively, showing no significant difference from that of the control agent 5.7% emamectin benzoate water dispersant at the application rate of 1 g/667 m². 【Conclusion】 The results of this study suggest that metaflumizone has excellent insecticidal activity and rapid action against S. frugiperda larvae, especially against the 6th instar larvae in the laboratory, and exhibits good control efficacy against S. frugiperda in the field, suggesting that it can be utilized to control S. frugiperda in China.