烯虫酯对烟草甲和烟草粉螟的生物活性

为明确烯虫酯对烟叶仓储害虫烟草甲和烟草粉螟的生物活性, 采用卵卡浸渍法测定烯虫酯对孵化率的影响, 采用浸叶法测定对化蛹率、羽化率和发育历期的影响。结果表明, 烯虫酯对烟草甲和烟草粉螟的致死效果随浓度的升高而增强。烯虫酯可显著降低两种害虫卵的孵化率、幼虫化蛹率及成虫羽化率, 并可明显延长幼虫的发育历期。其中, 5 mg/kg烯虫酯处理烟草甲和烟草粉螟卵7 d的校正死亡率分别为67.2%和50.7%, 处理烟草甲幼虫42 d的校正死亡率为57.1%, 处理烟草粉螟幼虫84 d的校正死亡率为60.1%, 幼虫化蛹率分别为9.6%和3.6%, 成虫不能正常羽化。因此, 5 mg/kg为室内筛选出的可同时防治这两种害虫的烯虫酯适宜浓度。

Biological activity of methoprene against Lasioderma serricorne and Ephestia elutella

In order to clarify the biological activity of methoprene against Lasioderma serricorne and Ephestia elutella, we used the egg card impregnation method to test the effect of methoprene on hatching rate and the leaf impregnation method to test the effect of methoprene on pupation rate, emergence rate and developmental duration. The results showed that the lethal effect of methoprene on L.serricorne and E.elutella increased with the increase of concentration. The egg hatching rates, larval pupation rates and adult emergence rates were significantly reduced, and the larval developmental duration was significantly prolonged. The corrected mortalities of L.serricorne and E.elutella eggs treated with 5 mg/kg methoprene for 7 d were 67.2% and 50.7%, respectively, those of L.serricorne larvae for 42 d and E.elutella larvae for 84 d were 57.1% and 60.1%, respectively, the pupation rates of larvae were 9.6% and 3.6% respectively, and adults could not emerge normally. Therefore, 5 mg/kg is the appropriate methoprene concentration to be screened in the laboratory against the pests.