Plate-thigh beetles

Definition

A family of small, obscure beetles (Eucinetidae) in the superfamily Scirtoidea, characterized by expanded, plate-like hind femora that partially cover the abdomen and hind coxae. Adults are typically found in moist, decaying organic matter such as leaf litter and rotting wood, where they feed on fungal hyphae and spores. The family is cosmopolitan but poorly studied, with approximately 50 described species in four genera. Larvae are elongate and campodeiform, adapted for moving through interstitial spaces in decomposing substrates.

Etymology

Common name refers to the distinctive flattened, plate-like expansion of the hind femora; family name Eucinetidae from Greek eu- (well, truly) + kinetos (movable), alluding to the functional hind legs.

Example

Eucinetus morio, a North American plate-thigh beetle, is frequently collected in hardwood forest litter samples during late spring, where its dark, compact adults (2–4 mm) are recognized by the diagnostic hind leg morphology.

Synonyms

• Eucinetidae

Related Terms

• Scirtoidea
• Clambidae (minute beetles)
• Elateroidea
• Fungivory
• saproxylic beetles
• leaf litter fauna
• cryptic beetle families

Usage Notes

The common name is used primarily in North American entomological literature; European sources more commonly use only the family name Eucinetidae. Not to be confused with similarly obscure families in the same superfamily (Clambidae, Decliniidae). Identification to family requires examination of the hind femoral structure, which is synapomorphic for the group.