Carpenter bees drill into Atlantic Highlands, NJ home

With consistently warm temperatures, carpenter bee season is now in full swing. Carpenter bees overwinter (hibernate) during the winter. When temperatures start to warm in the spring, they resume their activities — they mate and pollinate (feed off the pollen and nectar of flowers which permits fertilization of the flowers). Spring is carpenter bee mating season, and for these wood-boring insects, mating season means drilling season! There’s a reason why they’re called “carpenter” bees! The females excavate tunnels in wood for shelter and as brood chambers for their young. The females deposit an egg, and leave a mixture of pollen and regurgitated nectar as food for the larvae You’ll see nearly round entrance holes drilled into wood that look like they were made with a 1/2-inch drill bit. The other common signs of carpenter bee activity is what they leave behind — “frass,” the sawdust-like material from their drilling and stains from their waste droppings. Of course, you’ll often see these bees flying around, especially the males protecting the galleries (males do not have stingers, and the females rarely sting).  

Carpenter bees resemble bumblebees in size and appearance, but have a shiny black abdomen instead of a hairy yellow one. It’s very common for homeowners to see carpenter bees flying around the roofline. They seek out unpainted wooden building materials, especially wood that is weakened and damaged from water, and will clean out and enlarge existing tunnels as well as excavate new ones. Over time, new and expanding generations of bees can collectively cause considerable structural damage. The holes allow water seepage into the wood, and the larvae are an attractant for woodpeckers. 

I often find carpenter bees nesting underneath the home’s fascia boards that run along the lower edge of the roof, like in this home in Atlantic Highlands, NJ Because of their location near the gutters and roofline, they are susceptible to water damage, and are a potential trouble spot for carpenter bees and other insects, as well as an entry point for squirrels and other wildlife to gain access into the attic. For me, one of the best ways to determine whether they are nesting is finding the regurgitated wood debris (“frass’) that accumulates beneath their galleries (unlike termites, they don’t eat the wood). Once I find their nesting locations, I treat the infestation by applying a dust that expands after finding its way into the galleries. These bees do not dig a straight line into the wood. Rather, they dig a little hole about an inch deep and then turn at right angles to tunnel along the grain of the wood.  

Once the dust comes into contact with the bees and their larvae, it does not take long for the infestation to be resolved. These bees can cause a lot of damage, and homeowners should deal with these infestations in their early stages.