5%除虫菊素乳油对孔雀竹芋红蜘蛛的防效

Efficacy of 5% Pyrethrin on Tetranychus cinnbarinus of Calathea makoyana

采用800、1 000、1 200、1 500倍4种浓度的5%除虫菊素乳油对孔雀竹芋红蜘蛛进行防效试验。结果表明:800、1 000倍液5%除虫菊素乳油对孔雀竹芋红蜘蛛的防效浓度效果最好,防效可达90%以上,能有效防治孔雀竹芋红蜘蛛;且5%除虫菊素乳油药后3d和药后5d对孔雀竹芋红蜘蛛的防治效果比药后1d略有下降,药后7d其防效大幅下降,降到80%以下,因此,建议生产中施药间隔时间以7d为宜。

Efficacy tests on Tetranychus cinnbarinus of Calathea makoyana for 5% pyrethrin in concentrations of 800 folds, 1 000 folds, 1 200 folds and 1 500 folds were studied. The results showed that best effect, which was over 90%, appeared with concentrations of 800 folds to 1 000 folds, however the results on 3 d and 5 d were declined comparing with 1 d after application,and the effect dropped drastically,which was not up to 80% on 7 d. Therefore,an interval of 7 d was suggested in practice.