Carpenter Bees and How to Get Rid of Them

Carpenter Bees and How to Get Rid of Them Carpenter bees can be a real nuisance. They resemble large bumblebees and can be found buzzing around dwellings and other structures where they like to build their nests. Every year, they cause millions of dollars in  damage to dwellings by tunneling into decks, porches, and other wood structures. They can also be aggressive, especially during mating season, and will fly very close to human beings and even bump into them. Fortunately, they rarely if ever sting people and their nests can be removed. Carpenter Bee Basics There are several species of carpenter bee in the United States, but the most common one is the Virginia carpenter bee (Xylocopa virginica). These bugs are found throughout the Southeast but range as far as Connecticut to the north and Texas in the west. Carpenter bees range in size from about 5/8 of an inch to 1 inch and look very similar to bumblebees, but theyre not the same.   Bumblebees (genus Bombus) nest in the ground, usually in abandoned rodent nests, and live in social communities. Carpenter bees (genus Xylocopa) are solitary bees that burrow into wood. You can differentiate the two by examining the dorsal (upper) side of the abdomen. If its shiny and hairless, its a carpenter bee. A bumblebee, by contrast, has a hairy abdomen. Both are considered beneficial insects because they are  excellent plant  pollinators. Therefore, you should avoid eliminating these insects unless absolutely necessary. Carpenter bees usually live for about one year. Each new generation is hatched in the late summer, emerging from nests in August and September to grow and feed, pollinating flowers as they go  before  settling in for the winter and hibernating. Survivors emerge in April and May to mate. The female carpenter bee excavates a tunnel for her offspring. In each brood chamber, she stores food and lays an egg. Having reproduced, adult carpenter bees die off in July, leaving the new generation to continue the cycle when they emerge a month or so later. Most people encounter carpenter bees during April and May when theyve just emerged to mate. During this time, male carpenter bees tend to hover around nest openings, looking for receptive females. It can be rather unnerving being around them, as the males will also hover aggressively around people who approach the nests. They may even fly right into you. Despite this tough act, male carpenter bees cannot sting. Female carpenter bees can sting, but almost never do. How to Identify Nests If you see a bee emerging from a hole in the ground or within a structure, thats a good indication that youre looking at a carpenter bee nest. To be certain,  look at the entrance holes. A carpenter bee makes an entrance hole slightly bigger than her body, or just about  ½ inch in diameter. The first inch or two of the tunnel is usually made against the wood grain. The bee will then make a right turn and extend the tunnel another 4 to 6 inches in the direction of the wood grain. Carpenter bees will often eliminate their waste before entering their nest, so you might see yellow stains on the surface of the wood, just below the entrance hole. Stavros Markopoulos / Getty Images Though they burrow into wood, carpenter bees dont eat wood like termites do. Since their nest tunnels are limited in size, they rarely do serious structural damage. However, because such excavation requires a lot of energy on her part, a female carpenter bee will often prefer to refurbish an old tunnel to digging a new one. If carpenter bees are allowed to tunnel in the same structure year after year, however, the cumulative damage can be significant.   How to Control Carpenter Bees Your best defense is a good offense. Carpenter bees prefer to excavate untreated, unfinished wood. You can prevent carpenter bees from nesting in the first place by painting or varnishing your homes exterior. If an infestation has occurred, you will need to use an insecticide to eliminate the carpenter bees. Many professionals recommend sprays or dust, which can reach the interior surface of the entrance holes. Apply the pesticide at dusk, when carpenter bees are less active.   For the insecticide to work, the bees much come in contact with it as they crawl through the entrance hole of the nest. Apply the appropriate insecticidal dust in the spring, just before adults emerge to mate. Once you see the bees emerge, wait a few days before filling in the nest holes with wood putty or filler. If you didnt apply the insecticide before the spring adults emerged, you will need to treat the nests in the spring, and again in late summer, when the next generation of adults is foraging. In the fall, seal the nest holes with steel wool, then close off the hole with putty, wood filler, fiberglass, or asphalt.   A professional pest control service is your best choice, especially if you have a large infestation because theyll have specialized tools that can reach deep into crevices. However, if you want to do it yourself, any name-brand insecticide formulated to kill flying insects should work. If youd prefer to use a natural remedy, there are several, including boric acid,  Diatomaceous earth, and citrus spray. You can also contact  your local extension office  to find out which insecticides are effective and legal for use on carpenter bees in your area. Sources Bamabara, Stephen and  Waldvogel, Michael. Residential, Structural, and Community Pests. North Carolina State University. July 2009.Houseman, Richard. Carpenter Bees. The University of Missouri Extension.  Jacobs Sr., Steve. Carpenter Bees. Pennsylvania State University. January 2014UC Davis staff. Carpenter Bees Management Guidelines. The University of California. June 2014.13 Home Remedies to Get Rid of Carpenter Bees. HomeRemedyHacks.com. 27 January 2015.