B型烟粉虱与浙江非B型烟粉虱的竞争

为了了解近年来入侵中国的B型烟粉虱(Bemisiatabaci)取代本地非B型烟粉虱的潜能,在室内将一个B型与一个浙江非B型烟粉虱种群混合饲养在不同寄主植物上,跟踪观察混合种群中两个生物型个体数量相对比例的变化。结果表明,当两种生物型在棉花(Gossypiumhirsutum)上以相同初始数量共存竞争时,经过6代,非B型完全被B型替代;而在西葫芦(Cucurbitapepo)上以相同初始数量共存竞争时,只经过2代,非B型即完全被B型替代。在棉花上,即使以非B型占87%、B型占13%开始共存竞争,经过225d后,非B型也完全被B型替代。这说明B型烟粉虱具有在短期内竞争取代浙江非B型烟粉虱的能力。经分析,B型除了寄主范围比非B型的宽这一点对其竞争有利外,较强的内在竞争潜能也是其能成功入侵并替代本地非B型烟粉虱的一个重要原因。

Competition between the B biotype and a non-B biotype of the whitefly,Bemisia tabaci (Homoptera: Aleyrodidae) in Zhejiang, China

In recent years the B biotype of Bemisia tabaci has been an invasive insect in China. To elucidate its potential to replace a non-B biotype of B. tabaci, native to Zhejiang, China, we reared both biotypes on various host plants in a series of laboratory experiments to observe the changes in their relative proportions. On cotton, when the two biotypes began competition in equal numbers, the non-B biotype was completely displaced by the B biotype after six generations, whereas on squash, the non-B biotype was completely dis- placed by the B biotype after only two generations. Even when the competition started with 87% of non-B biotype and 13% of B biotype in numbers, the non-B biotype was completely displaced in 225 days. The re- sults showed that the invasive B biotype has the capacity to displace the non-B biotype in a short period of time. A preliminary analysis indicates that, apart from the advantage of a wider host range of the B biotype over that of non-B biotypes, a stronger innate capacity for competition is another important factor in the suc- cessful invasion of the B biotype and its displacement of the native biotype.