Infested wood is honeycombed with tunnels filled with loosely packed whitish powder called frass. The latter is composed of very fine particles of undigested wood and fecal pellets. Frass often accumulates beneath infested material or on the surface of the wood below exit holes (Fig. 1). Unlike most other groups of wood borers, anobiids are able to digest cellulose with the aid of yeast cells found in their digestive tracts. Woodborers without this ability utilize only the cell contents (starch) for nutrition. For successful development, infested material must have a moisture content of 13-30%. Lyctids or true powder-post beetles occur in the family Lyctidae (lick-teddee). Adults are 0.05″ to 0.25″ long, elongate, narrow and slightly flattened. When the reddish-brown to black beetles are viewed from the top their head is clearly visible (Fig. 5). To an untrained eye, the grub-like larva looks very similar to that of an anobiid (an-o-bee-id). Lyctids rarely are longer than 0.25″, however, and their legs are not as well developed. Wood may be infested for many years before the problem becomes evident.
By this time, the material is riddled with galleries that are packed with very fine wood dust, almost the consistency of flour or talcum powder. This dust eventually accumulates on and beneath infested material. Lyctids feed on the seasoned or partially seasoned sapwood of hardwoods. Wood with a moisture content less than 8% apparently is immune to attack and a moisture content of around 15% is near optimum. Susceptibility of Wood Products The susceptibility of wood products varies with type of wood (species, heartwood or sapwood) and moisture content, as mentioned above. Another important feature, which leads to an effective nonchemical approach for managing these pests of wood-inservice, is the fact that both species require openings in the wood for laying eggs. Anobiids utilize cracks in wood, joints that are not tight, openings beneath splinters, or old emergence holes to deposit eggs. Lyctids also may take advantage of cracks and splinters but most often they seek the ends of exposed cells or wood pores, such as those found on the transverse surface or end of a log or board. Members of both families are able to re-infest suitable material.
Managing these pests To manage these pests first entails an ability to recognize damage, to identify the extent of an infestation and to determine whether the infestation is active. Wood products in very dry environments or locations where humidity is greater than 30% are generally free of powder-post beetles.
Contact a professional insect exterminator for remediation of these insects.
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