The European hornet, Vespa crabro, is the only true hornet species established in North America, introduced to the eastern United States in the mid-1800s. It belongs to the family Vespidae, which includes other social insects like yellow jackets and paper wasps. Although not native, this hornet has become a naturalized part of the ecosystem, extending as far west as the Dakotas and Louisiana. Often mistaken for other large wasps, it plays a role in controlling local insect populations as a predator.
Identifying the European Hornet
The European hornet is noticeable for its large size, with workers typically measuring between three-quarters of an inch and 1.5 inches in length. Its distinct coloration helps separate it from other stinging insects. The head and thorax are a reddish-brown or mahogany color, while the abdomen shows a pattern of yellow and black stripes.
The black bands on the abdomen often have characteristic tear-drop shapes extending backward. This coloration distinguishes it from the bald-faced hornet, which is black and white and technically a yellow jacket species. The European hornet is also larger than the smaller, more slender yellow jackets, which exhibit a bold black and yellow pattern.
Another large insect often confused with Vespa crabro is the cicada killer wasp. The hornet’s abdomen is mostly yellow with brown markings, unlike the cicada killer’s, which is mostly black with yellow markings. The cicada killer is a solitary species that nests in the ground, unlike the social, cavity-nesting European hornet. The sheer size of the European hornet, combined with its unique coloration, makes it identifiable.
Nesting Habits and Behavior
European hornets are social wasps that construct large, annual nests from a papery material created by chewing wood fibers mixed with saliva. Their nests are typically enclosed within protected, dark cavities, including hollow trees, logs, wall voids of buildings, attics, and large sheds. Unlike bald-faced hornet nests, which are often suspended freely, European hornet nests are rarely exposed.
The nest paper is often a brittle, tan or brownish color and may sometimes be visible only through a small entrance hole in the cavity. Colonies can grow to contain between 200 and 400 workers by late summer, when their activity peaks. A behavioral trait that sets them apart is their activity at night.
Workers are frequently attracted to outdoor lights and windowpanes after dark, which can be alarming to homeowners. The adult diet includes tree sap, obtained by stripping bark from twigs, and sugary substances like ripe fruit. They are effective predators, capturing large insects, including flies and grasshoppers, to feed to their developing larvae.
Temperament and Sting Severity
The European hornet generally exhibits a less aggressive temperament than many common yellow jacket species unless its nest is directly disturbed. These insects are primarily concerned with defending their colony, so they are not likely to sting when foraging away from the nesting site. However, if a person approaches or vibrates a hidden nest, the hornets will quickly mobilize to defend their home.
The sting is comparable in pain level to that of a honey bee, but the hornet can sting repeatedly because its stinger is not barbed. The venom is a complex mixture of peptides, proteins, and enzymes, which contribute to the pain and localized swelling. While most people experience temporary pain, swelling, and itching, the risk of a severe allergic reaction, or anaphylaxis, is present for sensitized individuals.
Multiple stings can deliver enough venom to cause systemic symptoms, such as nausea, dizziness, or fainting, even in non-allergic people. If a nest is discovered, it is advised to maintain a safe distance and avoid attempting removal. Due to their tendency to nest in structural voids, professional pest control services are recommended to safely handle and eliminate an established colony.