Klamath-weed

Guides

Chrysolina hyperici
Saint John's Wort Beetle, St. Johnswort Beetle, Klamathweed Beetle
Chrysolina hyperici is a leaf-feeding chrysomelid beetle native to Europe and Asia, widely introduced as a biological control agent for invasive St. John's wort (Hypericum perforatum). The species has been established in North America, Australia, and other regions where its host plant has become problematic. Populations are often transient and alone do not provide sustained weed suppression, though the beetle can mechanically vector a host-specific fungal pathogen that enhances control effectiveness.
Chrysomelidae leaf-beetle biological-control Hypericum-perforatum St.-John's-wort Klamath-weed invasive-species-management mechanical-vector estivation