What are these insects?
These insects are called birch catkin feeders (or sometimes birch catkin bugs). They are a type of seed bug. They congregate on birch and feed on the catkins. These insects have also been reported on other plants, such as azaleas and rhododendrons.
Are they harmful to birch?
Birch catkin feeders feed on catkins with their piercing-sucking mouthparts. They do not have chewing mouthparts and do not feed on leaves. Any holes found in leaves is coincidence and is caused by some other problem. These insects do have well developed scent glands and can emit a pungent odor. However, this is just annoying and does not harm anything.
Are these insects pests in homes?
Birch catkin feeders can occasionally be found inside homes during late summer and fall. They may move inside looking for a sheltered place for the winter or hitchhike indoors on people's clothing or other objects. Fortunately people do not usually see too many at a time. They are also short-lived, not surviving for more than about a few days. Birch catkin feeders do not reproduce indoors. They are harmless to people and property and are just a nuisance.
What should you do about these insects?
No control is necessary for birch catkin feeders on your trees or in your homes. If there are large enough numbers in your home, just vacuum them. Otherwise, they are harmless and you should ignore them until they go away on their own by the end of the fall.
