湿度对木薯单爪螨Mononchellus mcgregori发育与繁殖的影响

【目的】木薯单爪螨是新入侵我国的重要检疫性害螨,主要危害木薯,也可危害橡胶。近年来,该螨种群数量迅速增多,扩散范围不断增大,目前已在海南、云南、广西、广东等重要木薯产区发生并加重危害,危害严重时可导致木薯减产40%~60%。湿度是影响木薯单爪螨发育和繁殖的重要因素之一,但有关该方面的研究较少。【方法】通过室内饲养,观察比较了不同湿度条件下木薯单爪螨发育及繁殖情况。【结果】当湿度为75%和85%时,卵孵化率均达100%,平均每雌产卵量分别达49.22和43.67粒,雌成螨寿命分别为21.00和22.00 d;当湿度为55%和95%时,卵孵化率和后代产卵量显著降低,雌成螨寿命显著缩短;当湿度为65%时,卵孵化率、平均每雌产卵量以及成螨寿命均与75%和85%湿度处理无显著差异,但其发育历期显著延长。【结论】75%和85%是木薯单爪螨发育与繁殖的适宜湿度条件。

The effect of humidity on the development and reproduction of the cassava green mite,Mononchellus mcgregori

Aim] The cassava green mite, Mononychellus mcgregori is a newly established pest on cassava in China. The species also lives on rubber tree (Hevea brasiliensis) and threatens the rubber industry. Recently, M. mcgregori was recorded in cassava-planting areas in Hainan, Yunnan, Guangxi and Guangdong Provinces, where it caused significant damage, reducing the fresh root yield of cassava by 40%-60%. Humidity is an important ecological factor for the development and the reproduction of M. mcgregori but precise information about the effect of various humidity conditions is lacking.Method] Effects of humidity on the development and reproduction of M. mcgregori were studied under laboratory conditions.Result] When the relative humidity (RH) was 75% and 85%, both of the hatching rate was 100%, mean fecundity per female was 49.22 and 43.67, respectively, longevity of female adults was 21.00 and 22.00 d. The hatching rate, fecundity and longevity of female adults significantly decreased at 55% and 95% RH. The developmental duration at 65% RH was significantly prolonged but the hatching rate, fecundity and longevity of female adults were not significantly different between 65% RH and 75%-85% RH.Conclusion] The most suitable humidity range is 75% and 85% for the development and reproduction of M. mcgregori.