Old House Borers

Old house borer (Hylotrupes bajulus)The old house borer is extremely destructive to wood with moisture content above 15-20%.  This 5/8-1” slightly flattened black to brownish adult insect has long segmented antennae.  The larvae are 1-1½ in length and feed mostly on moist wood.  The frass (sawdust) is granular after passing through the larvae’s digestive tract.  Large chambers may be produced in sections of wood going with the grain.  Larval development lasts up to 10 years.  After pupation of 20 days, the adults will emerge from oval cut-holes to mate and lay an average of 165 eggs in two to six batches that hatch in 9 days.

insects damage on old construction woodTreatment is spraying all exposed wood to kill the larva and adults that come into contact with the residual spray. We have found that the reduction of moisture in the immediate area will thereby reduce the moisture content of the wood in turn making reproduction next to impossible.  In basements, your heating system will help dry out wood along with a dehumidifier.  Remember, moisture reduction is the key to elimination.