Old House Borer
Contact: Eric Day, Manager, Insect Identification Laboratory
August 1996
Old House Borer
Size
3/4 to 1 inch (18-25mm)
Color
Black to dark brown
Description
Dark-colored, large, elongated beetle which burrows
in structural wood.
Habitat
The chewing sounds produced by the feeding of old house
borer larvae can be heard in wood during the spring and summer
months.
Life Cycle
The larvae feed little during the winter months of
December through February. The larvae can live in seasoned softwood
for several years. When the larvae are full grown, which usually
takes about five years, they emerge through oval holes in the
surface of the wood. Emergence occurs during June and July. During
the first few years of feeding, the larvae cannot be heard, but
when they are about four years old the chewing sounds are audible.
Type of Damage
Damage occurs to the wood in houses. The actual
structural damage caused by these beetles depends on the number
of larvae feeding, the extent of the infestation (how many years),
and whether there has been a reinfestation.
Control
Control of old house borers involves the use of insecticides
applied to the surface of wood or the use of an insecticidal gas
(fumigation). When there is an extensive and active infestation
of this insect, fumigation may be the best control method. However,
limited infestations can be controlled by applying insecticides
to the surface of the wood to prevent reinfestation and, perhaps,
kill larvae that may feed close to the surface and contact the
chemical just below the surface.
Interesting Facts
Are not limited to the wood in old houses-attack
new houses as well.