Overview

Both adults and larvae live in old, decayed logs and are thought to be associated with Myxomycetes. Although usually recognised as a distinct Adephagan lineage, Rhysodidae is sometimes placed within the family Carabidae, based on the presence of tactile setae, a carabid-like antenna cleaner, and structures of the pygidial defence system (Bell and Bell 1962; Forsyth 1972).

Description

Black and shiny, subcylindrical to slightly flattened beetles with stout, moniliform antennae and deep grooves on head and pronotum (and sometimes elytra and abdomen), which may be lined with very fine pilosity and are often filled with dried organic material. Legs relatively short, with weakly developed antenna cleaner on fore tibia; metasternum without transverse suture; mouth-parts more or less concealed beneath expanded mentum; head strongly constricted posteriorly to form narrow neck.

Larvae elongate, somewhat flattened and lightly sclerotised with short legs, no urogomphi, and transverse rows of asperities or interrupted ridges on T1 to 6 or 7; maxillae and labium reduced and usually clothed with fringed membranes.

Distribution

The family is represented in Australia by endemic groups ( Leoglymmius ), as well as Melanesian intrusions (Bell 1985). Most of our species are in the genera Kaveinga and Rhyzodiastes . [Bell and Bell 1978, 1979.]