Some 1800 species of Dermaptera (earwigs) have been described from all parts of the world (except the polar regions), but only about 60 are known from Australia.
All are elongate and flattened, the mobile, telescopic abdomen ending in a pair of forceps. They range from approximately 7 to 50 mm long, and vary in colour from buff to black.
They favour damp, confined spaces and are largely nocturnal.
Their relationships have been investigated by Giles (1963), who concluded that they are closer to the primitive Grylloblattodea than to any other orthopteroid order. This is supported by a number of subsequent authors including Matsuda (1976) (see Vickery and Kevan 1983, 1986), but not necessarily by recent investigations on the anatomy and embryology of the Grylloblattodea (Ando 1982), or the micromorphology of the spermatozoa (Baccetti 1987).
Elongate, prognathous, winged or apterous, exopterygote Neoptera, with cerci modified into terminal forceps; thorax with many free sclerites; when present, fore wings reduced to small tegmina, and hind wings membranous, semicircular, almost entirely made up of anal fan, and almost completely folded beneath tegmina at rest; legs relatively short, cursorial, tarsi 3-segmented; abdomen long, freely movable, telescopic.
The more primitive Pygidicranoidea are widely distributed in Australia, but the more advanced Forficuloidea are more restricted. The number of Australian species that have been described is not as large as might be expected, almost certainly as a result of inadequate collecting rather than of a poor fauna.
Most have been found in the wetter regions, but
have been collected throughout the continent. It is apparent that there is a considerable Indo-Malayan element, particularly in northern tropical regions. There is also a fair degree of correspondence between the faunas of North Qld on the one hand and of New Guinea, the Bismarck Archipelago and the Solomon Islands on the other.
Most Australian species, nevertheless, are endemic. There are noticeable differences between the known faunas of the east and the west of the continent, undoubtedly another consequence of spasmodic collecting.
Except for a few short papers by Burr, Mjöberg, Hebard and Hincks, referred to in Hincks (1954), and Giles (1965, 1970) and Brindle (1987) little has been written about Australian Dermaptera.