Overview

In south-western North America, larvae of B. fulva tend to remain motionless under loose bark or in rock crevices; when spiders or other small arthropods walk over the flattened body, perhaps attracted by an allomone, the larva pins the prey between the flexible head and tail spine and proceeds to pierce the cuticle and feed by extraoral digestion. Adults are rare and those of the Australian species have never been collected. [Blair 1930, Crowson 1973b, Lawrence 1989b.]

Description

Oblong, somewhat flattened, yellowish brown beetles with hind angles of pronotum acute and carinate and prosternum long, forming a chin piece beneath head. Antennae relatively short with apical segments slightly enlarged in female but with last 6 or 7 segments forming weakly pectinate club in male. Mandibles reduced; elytra weakly striate; tarsi simple; ventrites free.

Larvae strongly flattened and ovate, with complex lateral processes on all thoracic segments and abdominal segments 1--8 and with segment 9 produced posteriorly to form flexible, tapered spine. Head prognathous, with one pair of large stemmata, club-like antennae that appear 2-segmented, free but reduced labrum, perforated, falcate mandibles, and strongly consolidated ventral mouth-parts, with fused cardines and only partial sutures between postmentum and stipites. Thoracic spiracles are biforous, but those on the abdomen are reduced and annular.

Distribution

The only included genus Brachypsectra occurs in North America, India, Malaysia and northern Australia, where larvae of an undescribed species were taken in Winjana Gorge, W.A.