新型生物源农药与化学农药对草莓叶螨的防效对比研究

草莓叶螨是影响北京地区草莓生产的重要害螨,本文对其进行了两种新型生物源农药(藜芦碱、多杀霉素)及化学农药(高效氯氟氰菊酯、联苯菊酯)的防效对比研究。室内毒力测定结果表明:2.5%高效氯氟氰菊酯EC和0.5%藜芦碱SL对朱砂叶螨毒力最高,其LC_(50)分别为2.54mg/L和4.18mg/L;其次是10%联苯菊酯EC和2.5%多杀霉素SC,其LC_(50)分别为13.16mg/L和84.51mg/L。田间试验结果表明:2.5%高效氯氟氰菊酯EC和0.5%藜芦碱SL对草莓叶螨防控效果最好,施药7d后防治效果达80%以上,施药14d后防治效果达82%左右,施药28d后防治效果达84%左右,持效期较长。10%联苯菊酯EC和2.5%多杀霉SC素防控效果欠佳,施药7d后的防治效果为50%左右,具有一定的防治效果;但施药14、21及28d后害虫总数有增长趋势,未表现出持续的抑制效果。与对照区相比,各药剂均表现出对草莓叶螨具有一定的防控作用。高浓度2.5%高效氯氟氰菊酯EC对草莓叶片有轻微药害,在生产中要严格控制其使用剂量;0.5%藜芦碱SL试验处理未对草莓及非靶标生物产生不良影响,安全无药害且防治效果好,在实际生产中具有良好的推广应用价值。

Comparison of control effect of new bio-pesticides with chemical pesticides against strawberry mites

Strawberry mites are important pests in strawberry production in Beijing. This paper aims to explore the effects of controlling strawberry mites (Tetranychus cinnabarinus) with new bio-pesticides (veratrine, spinosad) compared to two chemicals (lambda-cyhalothrin, bifenthrin). The laboratory toxicity test indicated that the median lethal concentration (LC50) values of lambda-cyhalothrin and veratrine were 2.54 mg/L and 4.18 mg/L, respectively, while those of bifenthrin and spinosad were 13.16 mg/L and 84.51 mg/L, respectively. The greenhouse experiments indicated that lambda-cyhalothrin and veratrine showed high control efficacy and long-lasting effect, with the corrected control effect up to 80% after 7 days of pesticides application, above 82% after 14 days and 84% after 28 days, while, the corrected control effect of mites treated by bifenthrin and spinosad was about 50% after 7 days of application, and the population size showed increasing and corrected control effect showed undulating after 14 days, 21 days and 28 days of pesticides application. Compared to untreated controls, all of the pesticides had some control effect on strawberry mites. High concentration of lambda-cyhalothrin showed a slight phytotoxicity on strawberry leaves, so the dose of application should be strictly controlled in strawberry production. Veratrine was safe to strawberry and non-targeted organisms and the control effect was excellent, which can be recommended to popularize and apply in strawberry production.