Although wood infestations characterized by small holes and frass are usually referred to as powerpost beetle. The true powder post or lyctid beetles infest only hardwoods. The main culprits infesting softwood are usually anobiid beetles. In most cases they are a nuisance pest since it takes many years of activity for anobiid beetles to structurally damage. Since anobiid beetles prefer moist wood, moisture elimination should be a part of any control program.
The adult Lyctid powderpost beetle is a small (1/32-1/4 inch-long), cylindrical, brown beetle that attacks hardwood. Damage caused by the powderpost beetle is usually first detected with the appearance of holes in wood, 1/32 – 1/16 inch-diameter, from which a very fine sawdust may fall. Larvae of the powderpost beetle feed on many of the various hardwoods used in furniture, baskets, hardwood trim and flooring. Infestations in homes are almost always due to infestation of the wood prior to construction.
Powderpost beetles pass through four distinct life stages: egg, larva, pupa and adult. The larva is a creamy white, C-shaped grub with an enlarged thorax. The larval stage of the beetle is responsible for most of the actual feeding damage to the wood. The life cycle of a powderpost beetle normally requires about one year; however indoors, powderpost beetles may require two or more (possibly up to five) years to complete their development and emerge from the wood. For this reason, infestations may not be detected for several months, or even years, after completion of a new home.
The most commonly infested woods include ash, oak, hickory and walnut. Although powderpost beetles pose little threat to the structural integrity of most homes (which are framed with softwood lumber, thus not susceptible to attack), it is a reportable wood destroying beetle and can affect property resale value. It is also possible, though unlikely, that such an infestation could spread to hardwood furniture, trim, paneling, or flooring if left untreated. Powderpost beetles usually require unfinished wood (no paint or varnish) in which to lay their eggs. Female beetles emerging from infested wood search for a mate, and then lay their eggs on a suitable piece of wood. The most common site for egg-laying appears to be exit holes from which the females have emerged. In this way beetles can reinfest finished wood. Infestations can also spread to adjacent wood as larvae chew their way from one piece to another.
Source: Department of Entomology, Texas A&M University
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