Old House Borer
The Old House Borer is one of the most common wood destroying
beetle, with it's larvae hollowing out galleries in seasoned
softwood(pine). It is found in older buildings, but is more frequent
in newer buildings,(in houses less than 10 years old).The adults are
brownish-black to black, slightly flattened and about 3/4-1 inch
The average life cycle is usually one to three years, but can
take up to twelve years if nutritional and environmental conditions
are unfavorable. Because of the long life cycle, reinfesting the
wood it may take years before you see any structural damage .
The exit holes are about 1/4-3/8-inch in diameter, but damage may
have occurred for several years before spotting such holes. They are
able to digest cellulose.
When wood has been infested with fungi, the larval development is
faster. Their powder (frass) in the tunnels are like sawdust
• Prevention. Most beetle problems are
introduced into homes in lumber or finished
wood products (i.e., furniture, paneling, or
flooring). Most serious infestations occur when
infested wood is installed in the house. Inspect
wood to insure that wood is not infested at the
time of home construction.
• Wood finishes. Powderpost beetles only lay
eggs on bare, unfinished wood. Beetles will not
infest wood that is painted, varnished, waxed, or
similarly sealed. Beetles emerging from painted
or varnished wood were either in the wood
before finishing or were a result of reinfestation
by eggs that were laid in emergence holes of
adult beetles. Sealing holes prevents reinfestation
from eggs laid within the hole.
• Wood replacement. Infested wood can be
replaced if the infestation appears to be localized.
For instance, if emergence holes appear in a
member of a door or window frame, the piece
can be removed and replaced with a new, uninfested wood.
• Surface treatment. Insecticides are labeled for
surface treatment of bare, exposed wood.
Spraying or brushing insecticides onto infested
wood creates a barrier that kills adult beetles as
they chew their way out of wood. The barrier also
kills newly-hatched larvae as they attempt to
bore into wood. For the surface treatments to
work properly, they must penetrate the wood.
Therefore, the wood should be unfinished or
sanded to remove the finish. In certain situations,
the surface treatment can penetrate the wood
sufficiently to kill larvae within the wood to
prevent the further marring of the surface by
additional emergence holes of adults.
• Fumigation. Fumigation is considered the most effective
method of controlling wood-boring beetles. However, fumigation
can be the most costly method of control and does not provide
residual protection of the wood. Only pest control operators
certified to apply fumigants can do fumigation work. Fumigation
of infested furniture or small articles like picture frames and
baskets can be done without fumigating the entire structure.