organ on the underside of several apical

abdominal segments. It is also used to produce

and distribute defensive chemicals. Staphylinidae

have a stink organ at the apex of the abdomen,

and larger species such as the Devil’s Coach Horse

Ocypus olens raise the abdomen into a threat

position over their head, making them look

scorpion-like, while at the same time producing

a defensive smell. Some Carabidae,

particularly the bombardier beetles of

the genus Brachinus, have taken chemical

defense to an extreme, and have an

explosion chamber at the apex of the

abdomen, where, when alarmed, they

mix glandular secretions that allow

them to shoot a scalding hot cocktail

of chemicals at an attacker.

above | Lamprigera

A Bornean firefly larva,

filmed on long exposure,

leaves a trail of light from

its abdominal light organs.

opposite | Aegosoma scabricorne

(Cerambycidae) The female of this

European longhorn beetle extends her

abdomen to lay eggs in some timber,

guarded by the male.

below | Agelastica alni

(Chrysomelidae) Physogastric

female of the European Alder

Leaf Beetle with male.