These large (approx. 8-12 mm) beetles are in the Chrysomelid family, the leaf-eating beetles, and are found almost exclusively on milkweed, both swamp and common. One of the common names for them in fact, is swamp milkweed beetle, indicating their preferred Asclepiad! As you see, they can strip milkweed leaves to the rib and for this reason are not always welcomed by those growing milkweeds for monarchs. They have not been found at the FWG yet.