Hornets

Facts, Identification & Control

Scientific Name

Vespa crabo

Appearance

What Do They Look Like?

hornet image

  • Size: The adult European hornets are approximately 1-1.5 inches long. Queens are the largest member of the hornet colony.
  • Wings and Legs: Hornets have two pairs of wings and six legs.
  • Color: Dolichovespula maculata, the bald faced hornet, resembles a larger version of a common yellow jacket, except they have whitish-colored facial, thoracic, and abdominal markings. European hornets have a reddish-brown head, thorax, first abdominal segment, and legs.

How Did I Get Hornets?

Hornets overwinter near small crevices in home siding, tree bark, and rotten logs. But, the most likely place to find their nests is on the branches of trees and large outdoor, tree-like shrubs. In late spring, they build paper nests in tree branches and underneath eaves. The insects are often attracted to scraps near outdoor eating areas.

Homes with protected nooks on outdoor siding and hard-to-reach soffits provide ideal spots for hornets to make nests. These areas are within range of food sources like flowers, garbage cans, and road trash.

How Serious Are Hornets?

Are They Dangerous?
When hornets perceive threats near their nests, they become aggressive and can deliver painful stings. Angered hornets can also squirt venom into the eyes of enemies, causing temporary blindness. While their stings typically cause no long-term damage, the pain from stings is intense and people allergic to their venom may have serious medical reactions.

Sting Reactions
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. Typical symptoms and reactions to stings are:

  • Intense pain
  • Redness
  • Swelling around the site of the sting

Signs of Infestation

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

How Do I Get Rid of Hornets?

What Orkin Does
The first step in hornet control is to identify the pest. Once that is determined, your pest management professional (PMP) will develop a specific treatment plan for your individual needs. While sometimes possible, it usually isn’t wise to attempt any do-it-yourself efforts.

Complete control may require more than one treatment visit to ensure all of the pests are eliminated. Some components of hornet treatment plans may include:

  • Education – Educating homeowners on the predatory benefits of hornets as they prey on and reduce the numbers of many damaging insects. Also, the PMP will explain that nest removal is important since other insects may infest old nesting materials. They will also explain where hornet nest(s) were found and how they will be managed.
  • Chemical Treatments – Your PMP will explain any products and equipment that will be used. They may employ ready-to-use aerosol sprays, liquid sprays from power equipment, or an insecticide dust. These products are applied into nest entrances and help control hornets that are entering and exiting the nest. If it 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.
  • Non-chemical Removal – If populations are small and in exposed, easy-to-access locations, removing the nest without using insecticides may be possible. This is best done at night and involves using heavy plastic bags to cover and seal nests inside. It can then be removed and disposed. Remember, since hornets are aggressive and will furiously defend their nest, removal should be done while dressed in a fully protective bee suit and faced protecting veil.
  • Prevention – Your PMP will explain importance of using exclusion materials to prevent other hornets from entering homes. Homeowners should keep trees and landscape bushes well trimmed, thinned, and open. In general, this is because bald faced hornets prefer to build their aerial nests in hidden, protected portions of trees and bushes.

For more information or to schedule an inspection, please contact your local Orkin branch office.

Behavior, Diet & Habits

Where Do They Live?
European hornets are not as aggressive as bald faced hornets, but will nevertheless sting if their colony is disturbed. Hornet nests can be found in locations, such as:

  • Attics
  • Porches
  • Inside wall voids
  • Tree branches or hollows
  • Thick bushes

Nests
Hornet nests are constructed with paper-like material produced by the insects mixing their saliva together with the wood fibers they gather. Nest location is one of the differences between European hornets and bald faced hornets. European hornets usually nest in wall voids or in the open portions of attics, while bald faced hornets usually construct aerial nests in trees or large bushes.

What Do They Eat?
Adult worker diets consist of insects and plant nectar. Fruits and sodas will attract hornets.

Life Cycle

Growing Colonies
Colonies usually have an annual life cycle. Colony success depends on the ability of hornet queens to survive the cold weather of winter. Fertile hornet queens begin building new nests in the spring and also start laying eggs. As the eggs hatch and become hornet grubs (larvae), queens works to enlarge the nest. This is done by hunting for insects to feed to larvae.

In time, larvae mature, go through a pupal stage, and develop into the first generation of adults. At this point, queens cease work enlarging the nest to focus 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.

Mating
Around mid to late summer queens produce eggs that hatch and develop into sexually mature adult male and female hornets. These fertile adults leave their nests, mate, and the new fertile queens begin a new cycle. These queens are the only members of their colonies that have a chance to 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.

More Information

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.

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.