What Do Powderpost Beetles Eat?
Powderpost beetles primarily feed on wood, and their diet is highly specific. These beetles prefer wood that is high in starch and low in moisture, typically hardwoods such as oak, ash, hickory, maple, and some bamboo species. The adult beetles themselves don’t cause much damage because they feed very little, if at all. The real destruction comes from their larvae, which tunnel through the wood, consuming it as they grow.
These larvae digest the cellulose in the wood, turning it into a fine, powdery frass—hence the name “powderpost beetle.” They are particularly drawn to unfinished or untreated wood, because surface coatings such as paint, varnish, or sealants tend to prevent them from laying eggs or penetrating the wood. Wood with higher moisture content is less attractive; they prefer wood that has dried sufficiently, usually below about 20% moisture content, which allows the eggs to survive and the larvae to develop.
Some species may also infest bamboo or certain softwoods, but hardwoods remain their primary target. Infestations can go unnoticed for years because the internal tunneling occurs inside the wood, leaving only tiny exit holes and fine dust on the surface as outward signs.
Do Powderpost Beetles Eat Wood?
Yes, powderpost beetles do eat wood, but it’s primarily their larvae that feed. The adult beetles lay eggs in cracks, pores, or unfinished surfaces of wood, usually hardwoods with low moisture content and high starch. Once the eggs hatch, the larvae tunnel into the wood, consuming the cellulose and starch as they grow. This feeding creates a fine, powdery dust called frass, which is a key sign of infestation.
The adult beetles typically do not eat the wood—they mainly focus on reproduction—so the visible damage to structures, furniture, or flooring is caused by the larvae boring through the wood over months or even years. The types of wood most commonly affected include oak, ash, hickory, and other dense hardwoods, though some species can infest bamboo or certain softwoods if conditions are right.
Do Powderpost Beetles Eat Hardwood?
Yes, powderpost beetles primarily infest and eat hardwoods. They are especially attracted to dense, starchy hardwoods like oak, ash, hickory, maple, and some species of bamboo. Their larvae bore into the wood, feeding on the cellulose and starch, which creates the fine, powdery dust known as frass.
Softwoods are generally less susceptible because powderpost beetles prefer wood that is dry, well-seasoned, and low in moisture—conditions more typical of hardwoods used in furniture, flooring, and structural elements. The adults themselves rarely feed; all the destructive wood consumption is done by the larvae tunneling inside the wood.
Do Powderpost Beetles Eat Softwood?
Powderpost beetles rarely eat softwood. They have a strong preference for hardwoods that are dense, starchy, and properly dried—conditions that support the growth of their larvae. Softwoods, like pine, fir, or spruce, are generally too low in starch and have higher moisture content, making them unsuitable for most powderpost beetle species.
That said, certain species, such as some in the Lyctinae subfamily, are highly specialized on hardwoods, while other less common wood-boring beetles may occasionally infest softwoods under specific conditions. For practical purposes, if you are dealing with powderpost beetle infestations, the focus is almost always on hardwood floors, furniture, cabinets, and structural timber, rather than softwood framing.
Do Powderpost Beetles Eat Cedar?
Powderpost beetles generally do not prefer cedar. Cedar is a softwood with natural oils and resins that make it resistant to most wood-boring insects, including powderpost beetles. Its low starch content and aromatic compounds create an environment that is inhospitable for the larvae, which need dense, starchy wood to survive and develop.
While extremely rare infestations could theoretically occur if the wood is very old, damaged, or stored in conditions that reduce its natural defenses, cedar is widely used in construction, closets, and chests precisely because it naturally deters wood-boring pests.
Do Powderpost Beetles Eat Pressure Treated Wood?
Powderpost beetles generally do not infest or eat pressure-treated wood. Pressure-treated wood is infused with chemical preservatives—such as alkaline copper quaternary (ACQ) or copper azole—that make it toxic or unpalatable to wood-boring insects, including powderpost beetle larvae. The chemicals also inhibit fungal growth, which further protects the wood, since beetles often prefer wood that has some degree of natural decay or high starch content.
While no material is completely “immune,” pressure-treated wood is considered highly resistant, and infestations are extremely rare. This is one reason why pressure-treated lumber is commonly used for outdoor structures, decks, and areas where pest resistance is critical.
Do Powderpost Beetles Eat Painted Wood?
Powderpost beetles generally do not infest or eat painted wood. The paint acts as a barrier, preventing adult beetles from laying eggs on the surface and blocking larvae from reaching the wood beneath. These beetles prefer unfinished, bare, or lightly finished hardwoods because the larvae need direct access to the wood’s starch and cellulose to develop.
However, if the wood was infested before painting, larvae already inside can continue to feed and eventually emerge, creating tiny exit holes in the painted surface. Over time, this can lead to visible damage despite the coating. So while painting is an effective preventive measure, it does not eliminate pre-existing infestations.