Europe
Canada thistle (Cirsium arvensis)
Adults are metallic blue-black, have long segmented antennae, and their rounded bodies are up to 4 mm long. They emerge in late spring and feed on young Canada thistle leaves. Oviposition occurs on the underside of leaves. Larvae emerge in mid to late summer, and feed on Canada thistle leaves. When mature, larvae drop to the soil for overwintering.
Larval and adult feeding reduce photoshynthetic tissue and stunt plant growth and reproduction.
Randall, C.B., J.E., Andreas, J. Milan, and K. Gladem. 2024. Introduced Thistle Biocontrol Agents: History and Ecology in North America. In: R.L. Winston, Ed. Biological Control of Weeds in North America. North American Invasive Species Management Association, Milwaukee, WI. NAISMA-BCW-2024-8-INTRODUCED THISTLES-A. https://bugwoodcloud.org/resource/files/29169.pdf