小菜蛾的人工饲养方法优化和对几种农药敏感性测定

摘要

[目的]优化小菜蛾（Plutella xylostella L．）的人工饲养方法，筛选防治小菜蛾的有效药剂。[方法]在温度25±1℃、相对湿度60％～75％、光照周期L：D=（14：10）h条件下，用吹塑纸收集小菜蛾卵，用小油菜（Brassica chinensis）苗饲养幼虫；同时采用浸叶法，测定小菜蛾对5种供试药剂的敏感性。[结果]用小油菜苗饲养的小菜蛾发育状况良好，其蛹重为5．4mg／头，羽化率为94．O％，每雌产卵量为135．1粒。200g／L氯虫苯甲酰胺SC、20％氟虫双酰胺WG、150g，L茚虫威EC、200g／L虫酰肼Sc和1．8％阿维菌素EC对小菜蛾3龄幼虫的LC50值分别为0．152、0．223、1．151、93．340和0．128mg／L。[结论]该饲养方法操作简单，实用性强，适合于小菜蛾的批量繁殖；阿维菌素、氯虫苯甲酰胺和氟虫双酰胺对小菜蛾有较高杀虫活性，3种农药可交替轮换使用防治小菜蛾。%[Objective] The research aimed to optimize laboratory artificial rearing methods for Plutella xylostella L. and to select out effective insecticides against this pest species. [Method] Brassica chinensis seedlings were cultivated in the laboratory at （25±1）℃, 60-75% RH, and a photoperiod of 14：10 （L：D） h. The green blow molding papers were used to collect eggs, and Brassica oleracea seedlings were cultivated to breed Plutella xylostella L. until the insects were ready for use. Mean-while, the susceptibility of 3rd instar larvae of Plutella xylostella L. to five types of insecticides was tested by leaf-dipping method. [Result] Plutella xylostella L. larvae were found well-grown and uniform in developmental stages with average pupa weight of 5.4 mg, pupa emergence percentage of 94.0 % and egg number of 135.1 per female. The LCso values of 3rd instar Plutella xylostella L. larvae against 200 g/L chlorantraniliprole SC, 20% flubendiamide WG, 150 g/L indoxacarb EC, 200 g/L tebufenozide SC and 1.8% abamectin EC, were 0.152, 0.223, 1.151, 93.340 and 0.128 mg/L, respectively. [Conclusion] This rearing method is easy to be implemented and of great practicality, suitable for mass propagation of P. xylostella L. Abamectin, chlorantraniliprole and flubendiamide showed high insecticidal activities, so these three insecticides can be used alternately for the field prevention and control of Plutella xylostella L.