They are red brown, narrow and somewhat flattened.
The larvae are creamy white and measure 1/4" when fully developed.
Whitish, long and cylindrical eggs are laid by the female into the wide pores of hardwoods. She lays between 30 and 50 eggs, which hatch in one or two weeks. They are laid only if the starch content of the wood is high enough for the larvae.
The larvae pupate for between two and four weeks near the surface. The adult emerges by biting its way out between June and August.
The whole life cycle may take between four and ten years.
Of the four distinct life stages, the larvae do the most damage to wood. They will tunnel in the wood for between one or two years.
They are primarily pests of timber yards, but also cause considerable damage to furniture, sports equipment, wood block floors and joinery.