Brown lyctus beetle

Definition

A species of powderpost beetle, Lyctus brunneus, in the family Bostrichidae. Adults are small (2–7 mm), reddish-brown to black, and cylindrical, with antennae ending in two-segmented clubs. Larvae bore into and digest starch-rich hardwoods, reducing timber to fine frass; they cannot attack softwoods or lignin-dominant wood. The species is a significant pest of seasoned hardwood products, flooring, and furniture, with a nearly cosmopolitan distribution spread through international trade.

Etymology

From Latin brunneus (brown) and Lyctus, the genus name derived from Greek lyktos (ravenous, alluding to wood-feeding habits).

Example

Larvae of the brown lyctus beetle tunnel through oak floorboards and walnut cabinetry, leaving exit holes 0.8–1.6 mm in diameter and accumulations of talc-like frass beneath infested boards.

Synonyms

• brown powderpost beetle

Related Terms

• powderpost beetle
• Lyctinae
• Bostrichidae
• xylophagy
• Frass
• emergence hole
• Lyctus planicollis
• Anobiidae

Usage Notes

Distinguished from the closely related Lyctus planicollis (southern lyctus beetle) by subtle antennal club proportions and geographic distribution. Infestations require starch content >3% in wood; pressure-treated or heartwood-only products are generally immune. Not to be confused with anobiid powderpost beetles (family Anobiidae), which attack both softwoods and hardwoods and produce coarser frass with pellet-like granules.