Rhopalidae, or scentless plant bugs, are a family of true bugs. In older literature, the family is sometimes called "Corizidae". They differ from the related coreids in lacking well-developed scent glands. They are usually light-colored and smaller than the coreids. Some are very similar to the orsilline lygaeids, but can be distinguished by the numerous veins in the membrane of the hemelytra. They live principally on weeds, but a few (including the box elder bug) are arboreal. All are plant feeders. Currently 18 genera and over 200 species of rhopalids are known.