Control Potential Biological Control Potential As indicated above, Eurasian watermilfoil declines have been associated with the occurrence of herbivorous insects at numerous locations. These observations all indicate that the herbivores can control Eurasian watermilfoil, however, none is yet able to predict in advance when, where and how these herbivores will be effective. Newman et al.
Several issues appear to be important.
First, factors that limit weevil density and abundance must be investigated. Second, plant community response appears important. Lastly, the mechanism by which long term control occurs is not clear. Succesful biocontrol of Eursaian watermilfoil would reduce its abundance, eliminate surface matting and promote healthy native plant communities. Milfoil in tanks with weevils failed to reach the surface, mat, and flower .