Pacific-northwest-introduced
Guides
Larinus curtus
Yellow Starthistle Flower Weevil
Larinus curtus is a small weevil native to southern Europe and the Mediterranean region, introduced to the United States in 1992 as a biological control agent for the invasive weed yellow starthistle (Centaurea solstitialis). Adults are dark brown to black with light-colored mottled hairs and measure approximately 6 mm in length. The species is univoltine, with larvae developing inside flower heads where they feed on developing seeds, achieving average seed reduction rates of 96% per infested head. While adults feed on flowers and pollen, the larval stage provides the primary biocontrol impact.