by Kari Nichols

Created on: July 04, 2009   Last Updated: July 05, 2009

If you see a European Hornet, you'll know it - it's the largest hornet in the eastern United States, measuring about one inch long. They'll startle you with their size. They have a sizable head, large eyes, and a large body, looking like they came out of a horror movie. But the good news is that they are not aggressive insects unless handled or defending their nest. They are most often noticeable is at night, when they are most active, as they are attracted to light. They are the only hornet that is active at night, and if you are near a light or a light colored object at night, you may see or hear them bumping into the light or a window glass.

You may see some of them slowly buzzing around fruit trees, feeding on the nectar of fruit, and ruining your crop of fruit before it ripens. They often can be seen around the bark of trees or on branches, feeding on the sap or chewing off a ring of bark to help with nest building. This activity is destructive to the plants they are chewing on, particularly small ornamental plants. They sometimes attack and feed on insects that are in the cracks of tree bark, which are taken back to the nest to feed the larvae.

European Hornets are most active in summer, and while they can be quick, they usually fly rather lazily, as if it is a lot of work to keep such a large insect moving. They prefer to nest in protected areas, such as a hollow tree, shed, barn, or in walls. In the open, they will build a papery-looking football shaped nest, generally only ten feet or so off the ground. This is the only place they are aggressive, when defending their nest or themselves.

They become a problem when they are nested or seeking food in areas of human or animal activity. It is wise to stay at least 10-15 feet back from a nest, and avoid sudden movement. To protect their colony, they also attack other insects that venture too close, which often stimulates those insects to aggressive behavior.

In the fall they should be observed to be sure they are not going into cracks in house walls or roofing, as they will nest where the queen will overwinter and repopulate the nest in spring. Their nests are undesirable not only because of their activity, but because they will drip waste material out of the bottom which is a nasty smelling black liquid.

The European Hornet queen survives by essentially hibernating in freezing temperatures, which is the safest time to remove or destroy a nest. They are killed with commercially available hornet spray, but care must be taken because their size will produce a painful sting.

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