Thistle Tortoise Beetle

The thistle tortoise beetle, Cassida rubiginosa, is a beetle in the family Chrysomelidae, subfamily Cassidinae, with a green or yellowish-green rounded back that turns brown after preservation, and it measures 6 to 8 millimeters long. It is found across North America, from South Dakota to Virginia and from Alberta to New Brunswick, and across Europe from Fennoscandia to Greece and Spain, including Great Britain and Siberia, and it feeds on thistles such as Canada thistle, bull thistle, musk thistle, plumeless thistle, and field thistle. First recorded in North America in 1902 at Levis, Quebec, it is used as a biological control agent against thistles, though parasitism sometimes limits its effectiveness, and its larvae build a fecal shield for defense against predators. This description is adapted from Wikipedia contributors under CC BY-SA 4.0; changes were made. https://creativecommons.org/licenses/by-sa/4.0/