Reference

It was first released as a knapweed biocontrol in the 1980s in the United States. It is established in much of the western United States and there is evidence that it reduces knapweed biomass. ... Cyphocleonus achates was released to the Hiawatha National Forest in Michigan's Upper Peninsula in summer 2009. [7]

U. S. Forest Service (Hiawatha National Forest) NRCS, Upper Peninsula Resource Conservation & Development Council ... This summer, the Hiawatha National Forest released two different species of biocontrol insects to control spotted knapweed, a non-native invasive plant. ... each site received approximately 200 Cyphocleonus achates and 2,000

Cyphocleonus achates was released to the Hiawatha National Forest in Michigan's Upper Peninsula in summer 2009. References. Coombs, E. M., et al., Eds. (2004). Biological Control of Invasive Plants in the United States. Corvallis: Oregon State University Press, 212.