Pleocoma

Pleocoma is the only extant genus of rain beetles (family Pleocomidae) and is endemic to the Pacific states of North America. Fossil remains of Pleocoma have been found in the Yixian Formation in China, suggesting beetles in this genus have existed in something like their present form since at least the Cretaceous period. There are 27 described species in Pleocoma.

Possessing a robust oval body form similar to other scarabaeiforms, their ventral side is densely covered with fine, long hairs (genus name derives from Greek (', abundant) and (', hair), extending to the legs and to the margins of thorax and elytra. The back is hairless and glossy. Overall colors range from black to a reddish-brown, while the hairs may range from yellow to red to black. The antennae are 11-segmented, with a club of four to eight lamellae, more than in any other group of the Scarabaeoidea. The mandibles are not functional, and the opening into the esophagus is closed off; adults do not eat.