Which group of wood-boring beetles produces very fine and powdery frass?

The group of wood-boring beetles that produces very fine and powdery frass is the Lyctids. These beetles are known for their ability to infest hardwoods, particularly those that are not properly dried or seasoned. The frass they produce is distinctive because it resembles a fine powder and is often found in small piles near the point of entry or exit of the beetles. This powdery frass is indicative of their feeding habits as they bore into the wood, creating extensive galleries and leaving behind this very fine waste material.

In contrast, the frass produced by other beetle groups, such as Bostrichids and Anobiids, tends to be more coarse and can vary in texture. Old house borers also create larger, more coarse frass as they primarily infest softer woods. Understanding these characteristics is crucial for proper identification and management of wood-boring beetle infestations.