dogbane beetle, (Chrysochus auratus), species of leaf beetle native to eastern North America. It feeds on dogbane and milkweed plants and is toxic to other animals that ingest it.
See also list of beetles.
The dogbane beetle is oval, convex, and between about 8 to 11 mm (less than 0.5 inch) in length. One of the most brightly colored members of its family, the insect is iridescent blue-green with a metallic copper, golden, or crimson shine. It is closely related to the cobalt milkweed beetle (Chrysochus cobaltinus)