Also called
dung chafer or
tumblebug, any member of the
scarab subfamily Scarabaeinae (Coprinae) of the insect order Coleoptera. The dung beetle forms
manure into a ball--sometimes as large as an
apple--with its scooper-like head and paddle-shaped
antennae. In the early part of the
summer the dung beetle buries itself and the ball and feeds on it. Later in the season the female deposits
eggs in balls of dung, on which the larvae will later feed.
Dung beetles are usually round with short wing covers (elytra) that expose the end of the
abdomen. They vary in size from 5 to 30 millimetres (0.2 to more than 1 inch) and are usually
dark in colour, although some have a
metallic lustre. On the top of the male's head is a long, curved
horn. Dung beetles can eat more than their own weight in 24 hours and are considered
helpful to man because they speed up the process of
converting manure to substances usable by other organisms.
The
sacred scarab of ancient
Egypt (Scarabaeus sacer), found in many paintings and jewelry, is a dung beetle. Egyptian
cosmogony includes the scarab beetle rolling its ball of dung; the ball represents the
Earth and the beetle the
Sun. The 30 segments of its six legs--actually, this species has only 20, but closely related ones do have 30--represent the 30 days of each month. An interesting member of this subfamily is the
Australian Macrocopris symbioticus, which lives in the
anus of the
wallaby. The Indian scarabs Heliocopris and certain Catharsius species make
very large manure balls and cover them with a layer of clay, which becomes so hard when dry that the balls were once thought to be old stone
cannonballs.
Members of other scarab subfamilies are also called dung beetles; e.g., Aphodiinae and Geotrupinae. Instead of forming balls, however, they
excavate a
chamber under a
pile of dung that is used during feeding or for depositing
eggs. The aphodian dung beetle is small (4 to 6 mm, or about 1/5 in.) and usually black with yellow wing covers. The earth-boring dung beetle (e.g., Geotrupes) is about 14 to 20 mm (about 1/2 to 3/4 in.) long and brown or black in colour. Geotrupes stercorarius, known as the dor beetle, is a common
European dung beetle.