What characteristic distinguishes true powder post beetles from other beetles?

The characteristic that distinguishes true powder post beetles from other beetles is their ability to reinfest milled lumber. True powder post beetles, which belong to the family Bostrichidae and include species such as the Lyctus type, are known for their capacity to penetrate and infest wood that has already been processed. Unlike some other beetle species, which may only infest wood in its raw form, true powder post beetles can live in wood that has been milled into products, such as furniture or flooring.

This reinfestation capability is particularly concerning for homeowners and woodworkers, as it means that even treated and finished wood products can be at risk. In contrast, the other options incorrectly describe attributes of true powder post beetles, like their affinity for hardwoods or softwoods. In fact, they primarily infest hardwoods, and their frass, or waste, is typically fine rather than coarse. This points to their specific feeding habits that are primarily associated with dry wood and the fine powdery waste they leave behind, but it is the ability to reinfest milled lumber that is the key distinguishing factor.