Overview
Our largest species is
Bostrychopsis jesuita
, which is widely distributed across the northern part of the continent and normally attacks wattles and eucalypts.
Xylion
,
Xylobosca
,
Xylopsocus
and related genera contain most of our smaller species, many of which have concave elytral apices with which the males block the tunnel entrances against predators and parasitoids while the female is laying eggs. In
Xylobosca bispinosa
the males have, in addition to the concave declivity, a pair of diverging spines, which are lacking in the female. [Crowson 1961a; Lawrence 1980; Vrydagh 1958.]
Description
Elongate, cylindrical to slightly flattened, black or brown beetles, with head prognathous and visible from above (Lyctinae) or strongly deflexed and concealed from above by prothorax (Dinoderinae and Bostrichinae). Antennal club usually relatively loose; eyes circular and strongly projecting laterally; lateral pronotal carinae weak or absent; hind coxae contiguous to widely separated, without coxal plates; tarsi relatively slender and not lobed beneath. In the more cylindrical, burrowing forms, the head, pronotum and elytral apices may be tuberculate, toothed or otherwise modified, and the fore tibiae may be dentate; these resemble scolytine weevils, which differ in having geniculate antennae with a more compact club, elongate, less protruding eyes, and lobed tarsi with a reduced 4th segment. Larvae C-shaped and very lightly sclerotised, with enlarged thoracic region and strongly retracted head. Most bostrichids bore into moribund or freshly felled trees, dead and dry sapwood, or other kinds of dry plant material containing starches and sugars. They cannot produce cellulases and thus are restricted to sapwood, which the larvae reduce to a soft powder, earning them the name powderpost beetles.
Distribution
There are three major introduced pest species in Australia:
Lyctus brunneus
, which attacks structural timber containing sapwood;
Dinoderus minutus
(Dinoderinae), which commonly infests bamboos, cane furniture or basketwork; and
Rhyzopertha dominica
(Dinoderinae), which is our most serious pest of stored grain. The native bostrichid fauna includes several Lyctinae (
Lyctus
,
Lyctodon
,
Trogoxylon
,
Tristaria
,
Minthea acanthacollis
) and a large number of Bostrichinae.