The Smallest Beetles

Featherwing beetles (fig. 1) are the smallest known beetles, the majority of the species being a millimeter or less in length. The common name is derived from the distinctive structure of the wings (fig. 2) which are believed to function primarily for passive flotation, as in the ciliate seeds of dandelions. These wings are normally folded out of sight under the wing covers or elytra, which in some genera are shortened and truncate. However, in preserved specimens the featherwings often project beyond the apex of the elytra and aid (together with the minute body size) in the recognition of this family.

The family Ptiliidae is widely distributed in temperate and tropical regions of the world. About 23 genera and 115 species are listed from the United States, but many more remain to be described and named. The beetles are very abundant in Florida and neighboring areas but are rarely seen by most entomologists because of their minute size and cryptic habits. Featherwing beetles are not destructive but are especially interesting from an ecological and evolutionary standpoint because of their special adaptations to life at the extreme lower limits of size in the order Coleoptera.