ARTHROPOD MUSEUM NOTES

Number 61 • July 10, 2008 • Jeffrey K. Barnes


Odd beetle
Order: Coleoptera
Family: Dermestidae
Genus and species: Thylodrias contractus (Motschulsky)

Odd beetle

The aptly named odd beetle is the most bizarre member of the family Dermestidae. Males and females bear little resemblance to each other. Males average 2.9 mm long and are elongate with long, slender antennae and legs. They have elytra, but the hind wings are of variable size or lacking. Females average 4.4 mm long and are larviform, lacking elytra and wings. The bristly larvae normally feed on dry animal matter and can be serious pests of museum collections, especially damaging dry, pinned insect specimens. They also have been known to feed on feather, mummies, and art prints, and they can damage tissue paper and fabrics in their search for food or a suitable place to pupate. It has been reported that larvae can live three to four years without food. The duration of the life cycle is highly variable, typically lasting a little over a year, but ranging from half a year to nearly four years. The odd beetle appears to have a Holarctic distribution.