ARCHOSTEMATA—Archaic Beetles

84

suborder

Archostemata

known species

40

distribution

Scattered distribution with a few species

known from all continents except Antarctica

habitat

Mainly in forest habitats, in and around

living and fallen trees

size

2–30 mm

diet

Larvae of most species, where the larval diet

is known, feed on fungi in dead wood or

roots. Adults may feed on pollen or tree sap,

but in some cases hardly feed at all

notes

The only known living species of

Micromalthidae is probably common

in North America, and has spread to

ARCHOSTEMATA

T

he few species of Archostemata that remain

in the world today closely resemble fossils

found in stone and amber from hundreds of

millions of years ago, showing that they have

changed little since the Paleozoic era. Of the five

living families of these ancient relicts, three are

now relatively well known: the small and rather

bizarre Micromalthidae and the larger Cupedidae

and Ommatidae.

Micromalthidae, tiny, wood-feeding beetles from

North America, have one of the strangest life cycles

ARCHAIC BEETLES

in the animal kingdom. They have ‘pedogenetic’

larvae, that is larvae that are themselves able to

produce more larvae as offspring. The secondary

larvae then eat their way out of the mother larva,

before molting and developing into other mother

larvae and fertilizing themselves—or, rarely,

pupating and becoming an adult. The adults

are an evolutionary dead end, as they apparently

have no functioning reproductive organs.

Cupedidae and Ommatidae, families quite

similar to each other, lack the peculiarities of