The suborder Adephaga is the second largest of the four living

suborders of beetles, with around 46,000 known species,

although 40,000 of these are in one large family, Carabidae.

Adephaga has a long fossil history, dating at least to the

Early Triassic period, more than 240 million years ago,

and by the Late Triassic, easily recognizable fossils of many

modern families are found. Adephagans live in a wide range

of habitats worldwide, from subterranean fissures to the

rainforest canopy.

All Adephaga have glands on the abdomen that produce

chemicals. In most cases these are used for defense, but they

have other functions, including antifungal and antimicrobial,

as well as modifying the aquatic habitat (such as breaking the

water surface tension, or as a propellant in some Gyrinidae).

These chemicals account for the characteristic smell of

Adephaga, and staining of the fingers that may occur after

handling carabids. Chemical defense is taken to an extreme

in the carabid subfamily Brachininae (bombardier beetles)

which can release a scalding hot cocktail of chemicals into

the face of a predator, with an audible pop.

ADEPHAGA

opposite | Tricondyla (Carabidae: Cicindelinae)

A wingless predatory tiger beetle found running on

the forest floor in Indonesia. These beetles mimic

large ants, a form of Batesian mimicry.