carpenter bees

Asked May 13, 2014, 3:40 PM EDT

our beautifully blooming wisteria has brought back carpenter bees who are busy burrowing into our neighbors side of our split rail fence. She has asked us to exterminate them but we don't think they are causing any harm. What is your advice? Do carpenter bees damage homes, as our neighbor fears?

New Castle County Delaware

1 Response

I am sure the bees are utilizing the wisteria's nectar and pollen resources but more likely is that the split rail fence is attracting the bees since they like to make nest tunnels in the wood. The fence itself is the source of the bees and the main attraction for the bees in terms of a suitable nesting site. It is even more likely that they emerged from nest holes in that fence that were made last year. The holes themselves do not cause too much damage, but the developing larvae inside can excavate out a larger area to grow. These bees do not eat wood but in large numbers could cause some structural damage to a fence. If they indeed have nesting holes in the fence new generations will be back this time of year every year. Carpenter bees are important pollinators, but I do understand people's frustration with them. If you do choose to exterminate them you must plug up any holes in the fence and paint the fence, or the bees will just come back, and unless you plug up all the holes you will continue to see their populations rise.