Abstract:【Background】Ragweed, Ambrosia artemisiifolia invaded Laibin, Guangxi Province in the 1980s and has spread to several parts of the township. In order to control its invasion, the tortricid Epiblema strenuana was released in Gaoling village, Laibin, Guangxi, on 24 May 2009. After three months, the control effect was up to 98%. 【Method】We performed a region-wide survey on the population status of E.strenuana and the safety for other crops. 【Result】E.strenuana established a stable population in Laibin. When the host plants in the original introduction area were all consumed, E.strenuana rapidly spread to adjacent areas invaded by A.artemisiifolia. During the survey, we did not found E.strenuana infestation on any surrounding crops. 【Conclusion and significance】E.strenuana had a significant control effect on A.artemisiifolia and seems safe for cultivated crops, so the species seems suitable for wider release in Guangxi Province. However, migration and formation of stable populations by E.strenuanawere not as fast as of its host plant, A.artemisiifolia, so we need to assist the migration of the biocontrol agent in order to control A.artemisiifolia.
