Carpenter Bees Leading The Pest Race This Spring

We asked Wayne White, Board Certified Entomologist, to help us understand a few mysterious details that homeowners observe with regards to Carpenter bees. Here is what he had to say.

This spring I'm seeing what looks like huge bumblebees, what are they?

When the outside temperatures hit the 80s, lots of insects wake from their winter of inactivity. Among them is the carpenter bee (Xylocopa spp.). 

In the Washington DC area, many adult carpenter bees emerge from the galleries in the wood where they spent the winter. 

The ensuing activity is a combination of mating, fighting, and territorial behaviors.  Because of their large size, carpenter bees are easily seen and heard, and the brazen behavioral characteristic that they exhibit is most obvious. 

Are they going to sting me?

The female (which has a black face) is capable of inflicting a sting, though rarely will unless provoked.

Why are Carpenter Bees hovering around my deck/front door/roof/etc.?

Like many other insects and mammals, spring is the mating season. In the case of the Carpenter bee, the female does much of the work of the pair. 

She begins the season by searching for or returning to a nesting site, where she will either drill a new tunnel or refurbish an old one. 

The tunnel or chamber is typically drilled into untreated or unpainted wood. This can also be the underside or backside of the fascia board, decking, or other wood areas around the exterior of a home. 

After mating, she will lay a series of eggs (provisioning them with pollen that she has collected) inside the chamber that she has created. 

The male, which has a shorter life span, serves as the protector of the female and the nest site. 

With yellow or white markings on its face, the male is the one who will dive-bomb anyone in its territory, often fighting with other males in the proximity of the nest site. 

How long can I expect to see them?

Carpenter bees will be active for much of April and May in the Washington DC area.  Much of the ‘drilling’ or new galleries in wood occur in May. 

A telltale sign is often the ‘sawdust’ that falls beneath a newly drilled hole… the result of much chewing by the female and her strong mandibles. 

After the female has provisioned the ‘nest’ with eggs and pollen for the hatching larvae to feed on, the females will die off and there will not be further carpenter bee activity until late summer when there is usually another generation in this area. 

Those adults that emerge in the fall will overwinter and re-emerge in the spring of next year. 

How can I Get rid of Carpenter Bees?  

The most effective deterrent to a carpenter bee invasion is a well-finished wood surface. Nail holes, exposed saw cuts, and bare wood are very attractive to tunneling females. 

Wood stains, oil-based paints, or polyurethane will go a long way to making the wood less inviting. 

Once carpenter bees have chosen an area to drill, you can treat carpenter bee tunnels with appropriately labeled pesticide formulations applied directly into the openings. 

After a day or so, the holes should be filled with wood putty or another material to discourage female carpenter bees from reusing these old galleries.  

What can American Pest do for Carpenter bees?

The first thing we will do is a thorough exterior inspection of the home, building, or property.  We can then appropriately identify how many carpenter bee holes need to be treated/or filled and make any suggestions or consultation as to any long-term preventative solutions.