來源： Jianqing et al. 2001
After host-specificity tests, weevils (Neochetina eichhorniae and N. bruchi) were first released at four rivers in Wenzhou and Zhejiang provinces in September 1996. Some 1000 individuals of a mixture of the two weevil species were released at each river. The weevils established at all the four rivers within one year of release. At Lincun River, about 50% of water hyacinth plants were killed in late spring 1998, while a native grass, Paspalum spp., recovered and occupied the space where water hyacinth grew. Since then, the density of water hyacinth has varied seasonally between 10 and 50% of coverage of the water surface. By means of water flow, the weevils spread rapidly to water bodies up to 40 km from the release site by the summer of 2000 (Ding et al., Unpub. Data).
最後修改 ： 24/07/2006 3:28:39 p.m.