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TRUE DUNG BEETLES

SCARABAEIDAE: SCARABAEINAE

T

he true dung beetles, or scarab dung beetles,

(subfamily Scarabaeinae) have a short fossil

history. The oldest unquestioned fossil is Eocene,

53 million years old, well into the Age of

Mammals. An association with mammal dung

remains today, and they are essential decomposers

in terrestrial ecosystems, clearing up the waste

products of both wild and domestic animals. Every

egg laid by a true dung beetle is accompanied by a

large ball of dung, enough to provide for the larva’s

whole development, so a great quantity of dung is

removed and buried by these industrious insects.

True dung beetles are divided into “rollers,”

which mold the dung into a ball and roll it

away from competitors before burying it,

and “tunnelers,” which dig a burial

shaft directly under the dung pile.

Especially in South America,

where much of the “megafauna”

(such as giant ground sloths and

elephant-like gomphotheres) is

extinct, many true dung beetles feed

and breed on carrion. These include

most of the brightly colored “rainbow

scarabs” of the tribe Phanaeini. The largest

scarabaeines are the genus Heliocopris, more than

2 in (5 cm) long, tunnelers often found around

elephants and rhinoceroses, where these producers

of large-enough dung piles still exist in the tropics

of Africa and Asia. Most dung beetles are powerful

fliers to move from one dung pile to the next, but

in some parts of Africa flightless dung beetles such

as the genus Mnematium can be found. The vast

ruminant herds of the African plains allow them

to walk between dung piles.

SCARABAEIDAE: SCARABAEINAE

subfamily

Scarabaeinae

known species

6,000+

distribution

Worldwide, most diverse in tropics and

subtropics, much rarer in northern and

southern climates (e.g. few species in

Canada, UK, Chile, New Zealand)

habitat

Many species live in grasslands and

savannahs with big herds of grazing

vertebrates. Tropical forests are rich

in smaller species, and some perch on

leaves  in the canopy waiting for dung

size

2–55 mm

diet

Most species develop and feed on

vertebrate dung. Several species,