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Common names

powder-post beetles, bostrichid beetles, twig and wood borers

General distribution


Component taxa

~100 genera with ~500 species.


Adult: Body shape typically elongate cylindrical and moderately to distinctly convex, rarely moderately to distinctly flattened. Size ranges from 2-50mm in length, most less than 20mm long. Most genera variable from yellow, brown or black, some with metallic hue. Head usually deflexed under hood-like pronotum and not visible from above. Antennae 8-11 segmented, typically ending in a 2, 3 or 4 segmented club, rarely appearing lamellate. Mandibles large and prominent, variable from blunt to bifid apically. Pronotum often cowled along anterior margin, or straight, flat and/or smooth. Tarsal formula 5-5-5, rarely 4-4-4 (e.g., Psoa). Elytra usually coarsely punctate, sometimes with costae present. Hindwing well-developed, R3 short and attached directly to RP from the RP-MP2 cross-vein; well-developed R-cell present. Abdomen typically with five visible abdominal segments, rarely 6.

Larva: Body lightly sclerotized, white to yellowish in color, "C-shaped" (scarabaeoid), elongate, cylindrical to somewhat flattened, and typically averaging between 2-60mm in length. Vestiture typically short and fine, sometimes with elongate setal patches. Legs are well-developed. Head typically retracted into prothorax and prognathous (except Endecatomus). Prothorax typically more enlarged than either meso- or metathorax. Abdominal segments 1-8 usually with well-developed pleural lobes. Longitudinally (most) or transverse (Lyctinae) oval pads located beneath the anal opening. Thoracic spiracles located posteriorly on the prothorax or on mesothorax. Abdominal terga without patches of asperities, but some transverse plicae may be present.

Pest information

Bostrichid beetles are well-known pests of wood and wood products, including seasoned lumber and furniture products. Some attack monocotyledonous plants as well (e.g., some Lyctinae and Dinoderinae). The lesser grain borer, Rhizopertha dominica (F.), has become a ubiquitous pest of stored grains and cereal products. Dunnage beetles in the genus Sinoxylon have become problematic and are becoming more ubiquitous through transport via wooden pallets and shipping crates (solid wood packing material [SWPM]). In North America other genera have become pestiferous on varied commodities, including: Bostrichoplites, Dinoderus, Heterobostrychus, Melalgus, and Prostephanus.


Site last modified: January 9, 2009