Beetles aren't necessarily the most exciting critter to many people. In fact they can give some people the absolute creeps! But some play a positive role in nature and are downright beautiful. Mention the phrase "borer beetles" and usually the reaction isn’t going to be a positive one. Most species of this “long-horned borer” beetle family can cause extensive damage to nature as they bore into live wood. Some of you may recall hearing about the dangerous imported Asian Long-horned Beetle, which devastated mature trees in several Eastern US cities during 1999 and 2000. This caused thousands of trees to be destroyed in Chicago and New York in particular! Harmful boring beetles will attack forest trees including maple, poplar, and alder. They kill the trees by boring large holes through the heartwood of the tree. This in turn causes serious damage to the live tree. Most of these long-horned beetle species which are harmful to trees have the long antennae and long bodies which are characteristic of this family. However, we are fortunate to have a native beetle to our area in this family which actually is beneficial to nature! Introducing: the Banded Alder Borer.
The Banded Alder Borer is very striking as it is 1-1.5 inches long with large black and white striped ("banded") antennae and black and white markings on the body. The antennae are longer than the body! It feeds on alder, ash and other hardwood trees. However, it feeds on the dead or decaying wood of these trees. This in turn is helping with the promotion of the decay of the dead wood in the ecosystem. They lay their eggs on the surface of the tree bark. As the larvae develop they then tunnel inward and later prepare pupal chambers which will be home until the beetle is "born" to life.
Typically you will only see single individuals of them during the summer. Occasionally, however, they are strangely attracted in groups to fresh paint on the sides of buildings during warm/hot weather! Speculation is that a volatile chemical in paint can mimic a certain attracting scent ("pheromone") which draws the beetles to each other. Some painters have returned from a lunch break only to find a number of them unfortunately dead in their open cans of paint. The Banded Alder Borer is the only known beetle that seems to display this potential attraction to freshly painted areas.
Don't expect to come across these lovely beetles very often as they actually are quite uncommon to see. But if you should be lucky enough to see one take a moment to get close and watch it. They do not bite and are not a pest in any way---there is no need for taking any actions to control them!