Rhinocyllus conicus and Trichosirocalus horridus were released in Georgia during the 1990's to control musk thistle, Carduus nutans. Both weevil species are established and have dispersed from intial release sites. Partial reductions of musk thistle have occurred, but musk thistle continues to be a serious weed in pastorial systems. Recently, R. conicus was recovered from Cirsium horridulum, a native, non-target thistle species.
Species 1: Coleoptera Curculionidae Rhinocyllus conicus
Species 2: Coleoptera Curculionidae Trichosirocalus horridus
Keywords: Non-target effects
The ESA 2001 Annual Meeting - 2001: An Entomological Odyssey of ESA