Conservation-risk
Guides
Rhinocyllus
thistle head weevil
Rhinocyllus is a small genus of true weevils (Curculionidae) comprising four described species. The genus is notable for its specialized association with thistles in the subtribe Carduinae. The most widely known species, R. conicus, was introduced to North America in the 1960s as a biological control agent for invasive thistles including musk thistle (Carduus nutans), but subsequently revealed significant non-target impacts on native North American thistles, including threatened and endangered species. The genus is sister to Bangasternus.