on the termites and flying insects attracted by

their light display. Pyrearinus is one of a number of

genera of bioluminescent click beetles, which have

some of the brightest lights of any insects. The

widespread New World genus Pyrophorus has two

“headlamps” on the back of the pronotum, and a

bright abdominal light, which is only visible when

the elytra are open and the insect is in flight. They

family, Drilidae. The bristly larva is a snail

predator, entering the shell of a large snail

and eating it from inside. The wingless,

larvalike female also feeds on snails,

while the small, soft-bodied male, looking

superficially more like cantharid than a click

beetle, flies in search of a mate and does

not feed. This bizarre group was only

placed taxonomically by using DNA

also light up if disturbed or threatened during the

day, presumably to alarm potential predators.

Many temperate-zone Agrypninae are less

impressive, but still include some large species of

the genera Alaus and Cryptalaus, the larvae of which

are voracious predators in dead wood. Other

genera such as the European Agrypnus have

predatory larvae that live in well-drained soil.

left | Pyrophorus

From Argentina, this

species shows the

“headlamps” that

light up with a

luminous bright

green when the

beetle is flying

or disturbed.

below | Agraeus

This strange genus

(the specimen

pictured here is

from Singapore)

escapes predators

by resembling

a bird or caterpillar

dropping.

opposite | Alaus oculatus

The Eyed Click Beetle from

North America is not luminescent,

but the eye pattern may startle

vertebrate predators.