The first and foremost best method of control with carpenter bees is to prevent them from ever infesting a structure.
Using a polyurethane or oil based paint to completely cover any exposed wood is a primary deterrent to the carpenter bees. It’s important to inspect those surfaces regularly to watch for any deterioration in the painted surfaces. When the paint or coating deteriorates, it leaves exposed wood that the carpenter bees are able to attack.
Wood stains that soak into the wood do not provide a barrier between the carpenter bee and the wood, and are ineffective at stopping carpenter bee infestations.
Carpenter bees control
Another way to prevent and control carpenter bees from entering a structure is to cover it in aluminum, asbestos, asphalt or vinyl siding, or use some other type of non-wood material to prevent the bee from gaining access to the bare wood.
When dealing with carpenter bees that already have excavations established, use daylight hours to locate and mark any tunnel entrances. Treatment should be done in the dark and on an evening when the weather is cool. This means the bees are more sedentary and less likely to be aroused by activity around the holes. However, you should still wear protective clothing so that you can avoid being stung if you disturb any female bees.
Carpenter bees control
Male carpenter bees are the ones that are generally more aggressive, but they do not sting. However, if you are disturbing the nest, they will fly aggressively around and dive-bomb you or any moving object that gets close.
Since carpenter bees are wood boring bees one approach to controlling carpenter bees is to seal each entrance hole to their excavations, thereby eliminating their ability to gather food, if they are sealed inside, and cut them off from their home, if they are sealed outside.To do this, mark each entrance that you find. Use a caulking compound of some kind, a wooden dowel also works well covered generously in wood glue, or you can use wood putty. As much as possible, fill the entire excavations with the sealing compound. Use a caulking gun or similar tool to compress the compound into as many of the galleries as possible.
Since the carpenter bees depend on their galleries to survive the winter and need them for protection during the winter, this method can be very effective in reducing or eliminating the population of the group. Because of behavioral conditioning, the bees stuck inside the galleries behind the barriers do not chew their way out a new entrance, and the blocked entrances are a severe deterrent to those trapped outside.
It is also effective to kill the single female, if she can be found in a new nest. You can accomplish this by simply swatting her, or capturing her, or otherwise killing her. If you are attempting to destroy a nest, then try putting a wire into the entrance hole and probe into the excavation, doing this may kill carpenter bee larvae and pupae.
After taking these measures, it’s recommended that you also use the sealing method to close off and fill all excavations in the wood. Painting the wood to prevent new excavations is also a good idea.
Carpenter bees are pests that should not be ignored. Carpenter bees make holes in places such as fascia boards, outdoor furniture, windowsills, roof eaves, shingles, railings, and telephone poles. Bees prefer wood that is more than two inches in thickness. There is evidence to say that they attack eastern red cedar and red cedar that is highly resistant to rot and most insects. Carpenter bees do not eat wood. They merely bore through the wood for shelter and as chambers to rear the young. Sometimes, these tunnels can be up to ten feet long. They make rather large holes in the wood destroying the strength of the wood. They will bore through any species of wood. The treated wood does not make any difference as carpenter bees do not eat the wood and the toxicity does not kill them. They prefer bare, unpainted, weathered softwoods, especially, woods such as pine and cypress. Painted or pressed treated wood is less likely to be attacked, even though there is no guarantee. Changing the species does not solve the problem, although the carpenter bees prefer wood that is a bit wetter than 10%MC that enables the bees to bore through the weak wood with ease.
Many control techniques have been reported. Non chemical or preventative controls include painting, and varnishing the wood, Killing bees individually, caught in a net, blocking the holes with staples or nail closed with gutter guard. As gutter guards are not aesthetically pleasing, fascia boards can be applied with gutter guard, and then some oil paint can be painted as a control method. Plugging the hole was another method. A squirt of appropriate poison was placed in the hole and then a wooden dowel is inserted into the hole. As carpenter bees return to the same hole year after year, and excavate and branch off further, the hole should be plugged. Laval bees and adults can be killed by inserting a wire into the hole. Some galleries may contain six cells and are four to six inches in length, and as galleries are being reused by many bees, sometimes they may branch off many times, and lengths of up to ten feet have been reported. The wire should be strong enough to penetrate through the wooden cells and also to take a right angle turn. The bee performs a meticulous drilling job, drilling an entrance of half an inch diameter against the grain, and when the tunnel is one inch deep, it starts drilling at a right angle with the grain of the wood.
As a chemical deterrent, a broadcast insecticidal spray onto wood surfaces attracting large numbers of carpenter bees is being used. A broadcast spray is warranted for places such as barns, wood shake roofs, or decking. A broadcast treatment is best accomplished with pump up or horse and sprayer when targets the wood surfaces such as fascia boards, joist ends of redwood decks, favored by the carpenter bee.
Deterrent surface application’s residual may last only for about one to three weeks, and the treatment will have to be repeated.