Published on 08/11/99

European Hornets Invade North Georgia Homes

North Georgians are running for the hills. Not for gold, but from gold-rimmed hornets -- European hornets, to be exact.

European hornets (Vespa crabro Linnaaeus) were first reported in North America about 1840 in New York. Since then, they have spread to most of the eastern United States, reaching as far west as Louisiana and the Dakotas.

Yellow Jacket Look-alikes

"Adult European hornets are very large, about an inch and half long," said Beverly Sparks, a University of Georgia extension entomologist. "They're brown bees with yellow abdominal stripes and pale faces. Because of their yellow markings, they are often confused with yellow jackets, but they are much larger."

Vespa crabro is also commonly called the brown or giant hornet. Sometimes mistakenly called the "Japanese" hornet, it's the largest and, technically, the only true hornet in the United States.

"European hornets usually are more of a problem in summer and fall, because that's when the colony has the largest number of bees and they will defend the colony," Sparks said.

Nest in Trees, Barns and Attics

They usually build their nests in hollow trees. But they're often found in barns, sheds and in attics and wall voids of houses.

European hornets rarely build nests that are free-hanging or unprotected. They often build nests at a cavity opening, rather than deep within, and the nests built in wall voids may emit a noticeable stench.

Night Flyers

Unlike most stinging insects, European hornets fly at night. Lighted windows or outside lights often attract them.

"The workers prey on large insects like grasshoppers, flies, yellow jackets and honeybees," Sparks said. "They can be pests for beekeepers."

They can also be pests for trees and woody ornamentals, including dogwood, birch, rhododendron, boxwood, lilac and horse chestnut.

"They tend to girdle twigs and branches to feed on the sap, and it can kill the tree or shrub," Sparks said.

Control Tips

While European hornets are beneficial in killing insects, if a nest is close to your home, you may need to control them. Here's how:

* During the day, inspect perimeter walls, attics, outbuildings and hollow trees. A stethoscope can be helpful in finding nests in wall voids. If you don't find the nest, return at dusk and watch for them. Use a yellow filter on your flashlight so you don't attract the hornets.

* Once you find a nest, treat it late in the day, when the hornets are calmest and most are in the nest. Use a labeled pesticide, and wear a bee veil.

* Aerosol formulations of pyrethroid are particularly effective when applied directly into the nest entrance. If it's an aerial nest or one in a hollow tree, use a bee pole to apply aerosols from a distance. Dusts of two carbamates also work well for void or subterranean nests.

* Direct the spray into the nest opening for five to 10 seconds. Then move quickly away from the area to avoid any of the hornets that may come out of the nest. You may need to repeat the treatment the next day.

* If the nest is in a wall of your home or other inaccessible area, call a pest control company. The nest will probably need to be removed.

(European hornet photo courtesy "J.B. The Exterminatior.")

Faith Peppers is the director of public affairs with the University of Georgia College of Agricultural and Environmental Sciences.