菠萝粉蚧和新菠萝灰粉蚧溴甲烷熏蒸处理研究

Methyl bromide as a quarantine treatment for Dysmicoccus brevipes (Cockerell) and Dysmicoccus neobrevipes (Beardsley)

菠萝粉蚧Dysmicoccus brevipes(Cockerell)和新菠萝灰粉蚧Dysmicoccus neobrevipes(Beardsley)是菠萝等热带水果上的重要害虫,均属我国进出境水果贸易中需要检疫处理的对象。为了建立两种粉蚧有效的除害处理方法,本文测定了溴甲烷熏蒸2h对两种粉蚧各虫龄的致死毒力。结果表明,两种粉蚧对溴甲烷具有相似的毒力反应,1龄若虫的耐药性明显低于其它各虫龄。菠萝粉蚧LC99最大值在19.4℃和28.8℃下均为3龄若虫,分别为30.32g/m3和18.17g/m3;新菠萝灰粉蚧LC99最大值在19.2℃和29.4℃下分别为3龄若虫和成虫,分别为29.19g/m3和18.41g/m3。确认实验表明,在25℃下,采用熏蒸剂量25g/m3,在19℃下采用40g/m3熏蒸2h可以使菠萝粉蚧和新菠萝灰粉蚧达到安全检疫处理要求。

Dysmicoccus brevipes and Dysmicoccus neobrevipes are important pests which need to be applied quarantine treatment on infesting tropical fruits at import and export ports. To establish an effective treatment method for those two mealybugs, nymphs from 1^st instar to 3^rd instar and adults were tested for their susceptibility to methyl bromide in 2 h laboratory fumigations. The results showed that both D.brevipes and D. neobrevipes had a similar dose response to methyl bromide. 1 st insatr nymph was the most susceptible life stage to methyl bromide as it compared to late growing stage such as 2^nd -3^rd instar nymph and adult. When D. brevipes fumigated at 19. 4℃ and 28.8℃ , the maximum values of LC99 were found at 3^rd instar nymphs with dose of 30. 32 g/m^3 and 18.17 g/m^3, respectively. For D. neobrevipes fumigated at 19.2℃ and 29.4℃, the maximum values of LC99 were found at 3^rd instar nymph and adult with dose of 29. 19 g/m^3 and 18. dl g/m^3, respectively. Confirmatory tests showed that at 25% a dose of 25 g/m^3 or at 19℃ a dose of 38 g/m^3 produced 100% mortality of all life stages, which can provide quarantine security treatment for these two mealybug species.