Large bees eating river birch

Asked September 1, 2019, 4:22 PM EDT

I noticed a swarm of bees eating the bark off my river birch that I planted three years ago. I am worried it will damage my tree. Is there anything I can do to prevent them from eating the bark? Is there something I can do myself or should I call a pest control company? They don’t seem aggressive, but I do have two small children who play near the tree and I don’t want them to get stung. So far, I have not been able to determine where the nest is located.

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1 Response

Those are European Hornets.

They strip bark from river birch and other preferred trees (such as lilac) to make their nests and obtain nourishment from the sap. They make their nests in a cavity, such as a hollow tree or wall void that is about 6 feet or more above the ground. Their nests are difficult to locate. They rarely make suspended, football-shaped nests like bald-faced hornets.

Mature trees can typically withstand damage form European hornets, but there may be some branch dieback if the damage is extensive. How large are your trees?

These hornets are typically active only in September to early October. We would keep your children at a distance.

If you want to remove them, read the links below. The best method is to find (not easy. watch where they go) and treat the nest with a wasp spray -- but be careful, they can be aggressive when defending a nest. A better idea may be to hire a professional.

There is additional information about European hornets, and what you can do, on the following web pages.