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There are two varieties of Powder Post Beetles that are of concern in Ontario.
True Powder Post Beetles (Lyctids)
Lyctids only damage hardwood articles, mostly products manufactured from sapwood. Round exit
holes 1.5 - 3.0mm in diameter, filled with fine talcum-like powder are characteristic damage signs.
The hardwoods attacked contain at least 3 percent starch and must have pores large enough for
the female to lay her eggs in them. Sound wood, which has not been properly seasoned, is
preferred. Lyctid attacks are commonly found in hardwood floors, door or window frames, and
mouldings of new houses and occasionally in furniture. The adult beetle is 2 - 7.5mm long,
reddish-brown to black, and slightly flattened. Its head, although bent downward slightly, is clearly
visible from above.
False Powder Post Beetles (Bostrichids)
Bostrichids are similar to lyctids in habits and also are able to digest cellulose. Most species feed
only on starchy hardwoods or bamboo, however, a few may also attack softwoods. Many species
require wood with bark for egg laying and do not re-infest wood in homes. Some species prefer old
wood, such as timbers in barns or sheds, partly because such timber contains fungi, which provide
proteins for the developing larvae. Bostrichids have coarser, more tightly packed tunnels filled with
wood dust and excrement (frass). The exit holes made by the adults are slightly larger than those
of the lyctids. The adult beetle is 6 - 13mm long and is reddish-brown to brown black in colour.
Unlike the lyctids, its head is not visible from above.
LIFE HISTORY
The lyctid beetle lays its egg in the surface pores of wood. Bostrichid beetles in contrast, bore into
the wood, and the female lays eggs in egg tunnels prepared by adult beetles or in pores leading
from the egg tunnels.
The larvae of both beetles tunnel through the wood creating a frass filled network. The texture of
the frass within the tunnels can be used to distinguish the two families of beetles. The lyctid beetle
frass is a very fine powder, while the bostrichid beetle frass is coarse, often containing small
fragments of wood. The larvae remain within the wood for varying lengths of time, depending on
the species and environmental factors before pupating. One report suggests that adverse
environmental conditions may lengthen the life cycle of the lyctid beetle from 1 year to 2.5 - 4
years. The emerging adult makes a small, round hole, 1 - 2mm in diameter, at the surface of the
wood through which it leaves. Emerging adults push frass to the surface as they leave. Holes
found in wood may indicate a previous infestation that no longer threatens further damage.
Tapping and probing the wood can be used to determine if the damage is recent. Frass will be
observed exuding from the holes if the wood has recently been under attack. Closing existing
beetle exit holes with putty is desirable because it permits detection of holes made after treatment,
which may indicate incomplete control.
Source: http://www.uoguelph.ca/pdc/Factsheets/PDFs/114PowderPostBeetles.pdf
Dragnet FT would be utilized
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