European Hornets

Facts, Identification & Control

Latin Name

Vespa crabro (Linnaeus)

Appearance

The European hornet is a large insect. The adults range in size between 2 and 3.5 cm  in length. They are brown with yellow stripes on the abdomen and a pale face. The workers can sting but they are not particularly aggressive around the nest.

Behavior, Diet & Habits

The European hornet, Vespa crabro (Linnaeus), gets its name from the fact that it was brought to the United States from Europe. It first came to New York around 1850. It has spread west to the Dakotas and south to Louisiana. It has other names, including giant hornet and brown hornet.

The European hornet is a social insect. This means that it lives in a colony. The colony starts in the spring with a fertilized queen that spent the winter hibernating. She finds a place to build a nest. She uses chewed-up cellulose from decayed wood to make the nest. The usual nest sites are holes in trees, but these insects also make nests in attics or wall voids of homes and occasionally in the ground. Sometimes the nests are exposed on the sides of buildings.

At first, the nest only has a few cells. The queen lays an egg in each cell. When the eggs hatch, the queen feeds the larvae nectar and insects. When the larvae have developed into adults, they take over the work. The workers are sterile female insects. The queen’s job is to produce eggs. Through the summer, the number of workers grows. They expand the nest and bring food for the larvae.

European hornets feed on large insects, such as grasshoppers, yellow jackets, and bees. Because of this, most people consider them to be beneficial. They also gather sap from plants. The workers are active at night. They are attracted to lights and they sometimes startle homeowners by flying into windows where lights are visible.

Reproduction

In late summer, male hornets and fertile females begin to hatch. The males mate with the fertile females. These will be the queens for the following spring. The fertilized females seek a hiding place to spend the winter. The males and the workers die as winter approaches.

Signs of a European Hornet Infestation

Sightings of the large workers indicate the presence of European hornets.

More Information

Controlling European hornets starts with an evening inspection. Since the workers are active at night, nighttime is the best time to watch them to learn where their nest is located.

Hornet nests are often difficult to reach and to treat. Because of safety concerns, it is advisable to call pest control professionals to treat hornet nests. They will have the equipment and the products that are necessary to control hornets effectively.