Hornets

Facts, Identification & Control

Seek the assistance of a medical professional anytime a hornet stings someone.

The general name hornet is frequently misused for just about any species of large, ferocious looking and stinging insect. To most people hornet is used to designate both the bald faced hornet and the european hornet, even though the european hornet is a true hornet and the bald faced hornet is actually in the same insect group as yellowjackets. Worldwide there is only about 20 species of true hornets, while only one true hornet, vespa crabo, is found in the united states. As its common name suggests, the european hornet is an introduced species to the u.s. from europe.

Scientific name

Vespa crabo

Appearance

What do hornets look like?
The adult european hornet is approximately 1-1.5 inches long and has two pairs of wings and six legs. Its head, thorax, first abdominal segment and legs are reddish-brown. The queen is the largest member of the hornet colony. European hornets are not as aggressive as baldfaced hornets, but will nevertheless sting if their colony is disturbed. European hornets tend to make their nests in secluded, aboveground locations such hollow trees, attics, porches and inside wall voids.

Dolichovespula maculata, the baldfaced hornet resembles a larger version of a common yellowjacket, except they have whitish-colored facial, thoracic, and abdominal markings. The queen is the largest member of the colony. Baldfaced hornets build their gray, rounded, paper-like nests above ground on tree branches, thick bushes, or in tree hollows.

Behavior, diet & habit

Hornet nests are constructed with paper-like material produced by the hornets mixing their saliva together with the wood fibers they gather. During the time that nests are being built, it is common to see hornets scraping away a thin layer of wood from a wooden fence, an old log or the side of an unpainted wooden building. While hornets are known for their ability to inflict a painful sting, they are very beneficial predators and help to control a variety of insects that could otherwise become pests. Hornets are social insects and will aggressively defend their colony (nest) from any intruders. The hornet adult’s diet consists of insects and plant nectar they consume to augment their dietary needs.

Reproduction

Hornet colonies usually have an annual life cycle and the success of the colony depends upon the ability of hornet queens to survive the cold weather of winter. Fertile female hornet queens that have over-wintered in a protected site begin building new nests in the spring months. Her role at that time of year is also to begin laying eggs. As the eggs hatch and become the hornet grubs (larvae), the queen works to enlarge the nest, hunt for and capture insects that she feeds to the hornet larvae. In time, the larvae mature, go through a pupal stage and develop into the first generation of hornet adults. At this point, the queen ceases her work enlarging the nest and feeding the nest members so she can concentrate her efforts on laying eggs. The first and subsequent generations of hornet workers assume the role of nest builders, protectors and food gatherers for the remaining members of the colony.

Depending upon the region where the nest is located, about mid to late summer the queen begins to produce eggs that will hatch and develop into sexually mature adult male and female hornets. These fertile hornet adults will leave the nest, mate and the new fertile queens will become the overwintering queens that seek out protected locations to survive the cold winter conditions. The overwintering queens are the only members of the colony that survive the winter. Once the subsequent spring months arrive, these overwintering queens will emerge to begin building and populating a new nest in a new location.

Signs of an infestation

The most obvious signs of a hornet problem are presence of adults and the observance of nests.

Distribution

European hornets are found in most parts of north america.

More information

When requiring control of a hornet problem, your pest management professional (pmp) should be contacted and requested to provide an inspection in order to correctly identity the insect and determine the location of its nesting sites. Once that is determined, your pmp will develop a specific treatment plan that involves all of the effective treatment measures, whether preventive, non-chemical or chemical treatment procedures. While sometimes possible, it usually isn’t wise to attempt any do-it-yourself efforts for hornet control. However, should you decide to attempt to destroy a hornet’s nest on your own, do so only after dark when most or all of the colony members have returned to the nest.

typical symptoms and reactions to stings by hornets are intense pain, redness and swelling around the site of the sting. When someone is stung multiple times or is highly allergic to the insect’s venom, there can be systemic reactions that may affect the entire body.

How Orkin Treats for Hornets

Most people use the common name hornet to designate both the baldfaced hornet and the European hornet, even though the European is a true hornet and the baldfaced hornet is actually in the same stinging insect group as yellow jackets. Therefore, when describing the treatment of hornets, the first requirement is for your pest management professional to provide an inspection and determine the identity of the stinging insects requiring control and the location of their nesting sites. Once the inspection and identification is complete, your pest management professional can develop a specific treatment plan that involves effective treatment measures, whether preventive, non-chemical or chemical treatment procedures. Some components of the hornet treatment plan may include:

  • Educating homeowners on the predatory benefits of hornets as they prey on and reduce the numbers of many damaging insects. Also, the pest management professional will explain that removing nests once the hornets are eliminated is important since other insects may infest old nesting material that is allowed to remain on the property or inside the structures.
  • Explaining why effective hornet treatment involves treating the nest, an explanation of where hornet nest(s) were found and how those nests will be managed is very important. Nest location is one of the differentiators between European hornets and baldfaced hornets. European hornets usually nest in wall voids or in the open portions of attics, while baldfaced hornets usually construct aerial nests in trees or large bushes.
  • Explaining the importance of using exclusion materials to prevent other hornets from entering wall voids or attic spaces and building new nests.
  • Recommending keeping trees and landscape bushes well trimmed, thinned and open so hornets are discouraged from building their aerial nests. In general, baldfaced hornets prefer to build their aerial nests in hidden, protected portions of trees and bushes.
  • Explaining what products and equipment will be used. Your pest management professional may employ ready-to-use aerosol sprays, liquid sprays from power equipment or an insecticide dust. These products are applied into the nest entrance and will help control hornets that are entering and exiting the nest. If the nest is located close to areas where people frequent, it is best to do the control work after dark when hornets are almost all inside the nest. Complete control may require more than one treatment visit to ensure all nest occupants are eliminated.
  • If the nest population is small and in an exposed, easy to access location, removing the nest without using insecticides may be possible. While nest removal is possible, it is best done at night and will involve using a heavy plastic bag to cover the nest and seal it shut. The nest can then be removed and disposed. Remember, since hornets are aggressive and will furiously defend their nest, nest removal should be done while dressed in a fully protective bee suit and faced protecting veil. You may want to contact your pest control professional.

Hornet Stings

Bald-Faced Hornets

The bald-faced hornet belongs to the Genus Vespula. Bald-faced hornets are more closely related to yellow jackets than they are to hornets.

Hornet Nest

Hornet nests are composed of a paper substance derived from saliva and wood pulp. They are located within or atop trees, in attic rafters and in other covered areas.

Giant Hornets

The Vespa Crabro is also known as the European or giant hornet. The giant hornet closely resembles the bald-faced hornet.

What do Hornets Eat?

Hornets are predaceous and feed primarily on other insects. Controlled populations of hornets can assist in pest control, although a nest located near or inside a home may prove extremely dangerous to humans.

Bees and Hornets

Bees are flying insects that feed on pollen and nectar. They have segmented bodies, two pairs of wings and antennae. Of these species, the Western honeybee is most revered.

Getting Rid of Hornets

Pest control professionals should be consulted before attempting to treat any hornet infestation. Hornets are typically aggressive, and some individuals may be allergic to their sting.

European Hornets

This hornet was brought to the U.S. from Europe and is a large brown insect with yellow stripes and a pale face. European hornets eat grasshoppers, yellow jackets and bees.