生物农药米尔贝霉素防治烟粉虱的特性

介绍了生物农药米尔贝霉素对烟粉虱的毒性及防效。有效成分1 mg/L米尔贝霉素对烟粉虱卵孵化率影响很小,但对1龄若虫致死率达100%。米尔贝霉素对1龄若虫的LC₅₀为有效成分0.02 mg/L;低用量有效成分2mg/L的米尔贝霉素与0.2%矿物油混合使用,药后3和10 d对成虫的致死率分别为96%和67%。在棉花田中,米尔贝霉素比氯氰菊酯具有更好的烟粉虱防治效果,且不伤害烟粉虱的寄生性天敌双斑恩蚜小蜂和浆角蚜小蜂。

Effect of Milbemycin on the Bemisia tabaci

Toxicity and control efficiency of milbemycin on Bemisia tabaci （Germadius） was introduced. Milbemycin of 1 mg a.i./L had slight effect on egg hatch, whereas it performed 100% mortality rate against 1st instars. The LC50 of milbemycin for 1st instars was 0.02 mg a.i./L. A mixture of 2 mg a.i./L milbemycin with 0.2% mineral oil resulted in higher mortality of 96% and 67% at 3 days and 10 days after application. In the cotton field trials, milbemycin gave the better control than cypermethrin and had no negative effect on parasitic natural enemies such as Encarsia and Eretmocerus.