Things You'll Need
1/2-inch wooden plug
Carpenter bees are wood-boring pests that will bore holes into the trim, siding, decks and fascia boards on your house to build their nests. They are especially fond of log cabins. The bees will also tunnel into wood lawn furniture, firewood, railings, shingles and shutters. The bees will reuse the nest year after year, digging the tunnel deeper into your home each time, which eventually weakens the wood. Entrance holes allow water to penetrate the structure and cause damage. Carpenter bee nest-entrance holes need to be plugged and sealed to prevent the bees from enlarging the nesting site and causing irreparable damage.
Begin treatment after dark on a cool evening. Carpenter bees are less active at night and when it's cool.
Wear protective clothing to prevent bee stings.
Treat the nest entrance hole with insecticide. There are several botanical and cypermethrin-based insecticides approved for use on carpenter bees. Check insecticide labels to be sure they are appropriate for carpenter beetles and follow label instructions for use.
Use a garden sprayer to apply insecticide and allow the area to dry overnight.
Plug the hole with a 1/2-inch wooden peg. Carpenter bee nest entrances are usually about 1/2 inch in diameter.
Caulk over the peg with exterior caulk and finish to match the exterior of the home.
Treat wooden surfaces with insecticide in the early spring to ward off carpenter bees.
If you have a large infestation of carpenter bees, consult a professional exterminator. Some of the best insecticides for use against carpenter bees are licensed for use only by professional applicators.