Overview
Both adults and larvae occur under bark and are predacious.
Description
As here constituted, the Cucujidae excludes the Passandrinae, Laemophloeidae and Silvanidae, which are sometimes considered as cucujid subfamilies. Adults are elongate, parallel-sided, strongly flattened, and glabrous, usually with very large heads (wider than the prothorax), relatively small eyes, moniliform antennae, a concealed labrum, small tibial spurs and distinct lateral pronotal carinae;
Pediacus
has a smaller head, exposed labrum and weakly clubbed antennae.
Larvae are distinctive in being very flat with a hinged, forked process (tergum 9) at the abdominal apex. Head very broad and flat; antennae moderately long with small sensorium; ventral mouth-parts only slightly retracted; mandibles with a highly reduced mola consisting of a slender, cuticular process, which may be lined with fine hairs; mala slender and falcate; legs widely separated; sternum 9 and segment 10 reduced and membranous, partly enclosed by sternum 8.
Distribution
Platisus
contains several species that are relatively common in eastern Australia, and an undescribed species of
Pediacus
is known from northern Qld.