溴甲烷对扶桑绵粉蚧的熏蒸处理研究

Methyl bromide as a quarantine treatment for Phenacoccus solenopsis Tinsley

为建立扶桑绵粉蚧溴甲烷熏蒸处理方法,本文测定了溴甲烷熏蒸2h对扶桑绵粉蚧各虫龄的致死毒力。用机率值分析表明:各虫龄对溴甲烷敏感性不同,以1龄若虫对药剂最敏感,以3龄若虫耐药性最强;在20℃和29.5℃下3龄若虫达到99%死亡率所需CT值分别为44.09 g.h/m3和29.77 g.h/m3,其对应的LC99分别为28.09 g/m3和18.10 g/m3。验证实验表明在21～25℃下以剂量38g/m3,在26～30℃下以剂量25 g/m3熏蒸2h各供试虫龄死亡率均达到100%,该指标可为扶桑绵粉蚧安全检疫处理提供参考。

In order to develop an effective fumigation treatment for cotton mealybug,Phenacoccus solenopsis Tinsley,nymphs from 1st instar to 3rd instar and adults of the P.solenopsis,were tested for their susceptibility to methyl bromide in 2h laboratory fumigations at temperature of 20℃ and 29.5℃,respectively.Based on probit analysis of dose-response data,it indicated that the 1st instar nymph was the most susceptible life stage and 3rd instar nymph was the most tolerant life stage to methyl bromide.The CT values of fumigation on 3rd instar nymph at 20℃ and 29.5℃ to achieve 99% mortality were 44.09 g.h / m^3 and 29.77 g.h / m^3,respectively.Accordingly,the LC99 for 3rd instar nymph at 20℃ and 29.5℃ were 28.09 g / m^3 and 18.10 g / m^3.Based on the confidence interval of LC99 for 3rd insatr,confirmatory tests showed that either at 26-30℃ a dose of 25 g / m^3 or at 21-25℃ a dose of 38 g / m^3 produced 100% mortality of all life stages.These results can be used as references for cotton mealybug quarantine security treatment with methyl bromide.