Cyphocleonus achates “Knapweed Root Weevil” Curculionidae

Missoula, MT
August 13, 2015
Robert Niese

These weevils are native to Europe, but were introduced in the 1980s as a potential biological control agent for various species of knapweed. Various studies have shown that they are actually quite good at reducing the biomass of Spotted Knapweed, and have been successful in various locations in Montana, Minnesota, Oregon, Nevada, British Columbia, and recently, Michigan.