European Hornet — Fact Sheet

Scientific name: Vespa crabro (Linnaeus, 1758) Common names: European hornet, brown hornet, giant hornet (sometimes — but this name has been confused with Asian giant hornet, see below) Family: Vespidae (subfamily Vespinae) Status in the San Antonio / Boerne corridor: Not established in Texas. Coverage page for identification, comparison, and to address common confusion with native species

At a glance

Why this page exists

European hornets are not present in Texas, but they generate enough customer questions that a coverage page is warranted. The two reasons:

1. People in San Antonio see large brown-and-yellow wasps and panic. What they almost always saw was a cicada killer (see fact sheet 10), a queen yellowjacket, or — rarely — a stray wasp from elsewhere. 2. "Giant hornet" or "European hornet" gets confused with Asian giant hornet — the species marketed as "murder hornets" during the 2020 media cycle. Customers who lived through that news coverage now remember "giant hornets in America" as a real threat. Education matters.

This page exists to handle that confusion clearly and to redirect identification questions to the actual local species likely involved.

Identification

If you genuinely encounter a European hornet outside its established range — say, on a piece of imported nursery stock or in a shipping container — here is what to look for:

• Large size: workers about 1 inch long, queens up to 1.4 inches. Larger than yellowjackets, smaller than the Asian giant hornet.
• Reddish-brown coloration overall, particularly on the head and thorax. Most American wasps are black-and-yellow; European hornet is more brown-and-yellow.
• Reddish wings — distinctive, not transparent like most wasps.
• Yellow abdomen with brown bands and characteristic teardrop-shaped brown markings at the back.
• Deeply C-shaped indented eyes — a diagnostic feature of Vespa hornets.

The species was first described by Linnaeus in 1758 in Systema Naturae. Various color forms exist across its native Eurasian range, but they are now treated as informal regional variants rather than formal subspecies.

Distribution — the actual range

European hornets were introduced to North America from Europe sometime around 1840, in the New York area. From this introduction point, they spread:

• Throughout the eastern United States, as far west as the Mississippi River
• North into the Great Lakes states, southern Ontario and Quebec
• South to Louisiana and as far as New Orleans
• Documented as far west as the Dakotas in scattered records
• Most common in the Washington, DC area

In 2010, isolated nests were discovered in Guatemala — believed to be recent accidental introductions rather than an established population.

They have not been documented as established in Texas. Scattered specimens have occasionally been collected in Arkansas (the closest established population), but the species has not crossed into Texas in any meaningful way. The reasons are not entirely understood — habitat suitability appears reasonable across East Texas — but the species has been remarkably non-invasive after its initial 19th-century establishment. ScienceDirect's Medical and Veterinary Entomology notes: V. crabro "is neither particularly abundant nor a pest in its new location" — striking, given that other introduced vespids (German yellowjackets, common wasps, European paper wasps) have become serious pests in the Americas.

Biology and behavior — for reference

Annual cycle: Like other vespines, colonies are annual. A mated queen overwinters, founds a new nest in spring, raises the first brood alone, and then transitions to full-time egg-laying as workers take over.

Nest: Built in dark, sheltered cavities — most commonly hollow trees, but also attics, wall voids, abandoned beehives, and barns. The paper has a brown color (not gray like baldfaced hornet nests) due to the bark fibers used. A few subterranean nests have even been reported.

Diet: Adults drink nectar and tree sap. Workers prey on large insects — grasshoppers, flies, dragonflies, moths, mantises — and bring them back to the nest as larval food. They also prey on honey bees, which has made them a minor pest of beekeeping operations in their European native range.

Tree girdling: European hornets strip bark from young deciduous trees and shrubs (lilac, birch, ash, dogwood, dahlia, rhododendron, boxwood) to feed on the sap. This girdling can kill young or ornamental plants. This is a distinctive behavior that distinguishes them from native North American wasps.

Worker policing — an unusual reproductive system: Unlike most vespines where queen pheromones suppress worker reproduction, European hornets use worker policing — workers actively destroy eggs that were not laid by the queen. This was not understood until relatively recently (the older literature assumed pheromone control as in other vespines).

Pheromones: The major alarm pheromone compound is 2-methyl-3-butene-2-ol. When a hornet is killed near the nest, this compound triggers attack behavior in nearby workers. Materials that contact the alarm pheromone — clothes, skin, dead wasps — can trigger sustained attack.

Two unusual behaviors worth knowing

1. They are nocturnal — the only nocturnal wasp in much of their range.

European hornets are active at night and are attracted to artificial lights. In Pennsylvania, they are documented as the only nocturnal wasp species. Workers will fly at night and beat themselves repeatedly against lighted windows, which can be alarming for residents who think the hornets are trying to break in.

This nocturnal foraging is unusual among vespines — most wasps are strictly day-active. European hornets exploit a foraging niche (night-flying moths, beetles, other large nocturnal insects) that other wasps do not.

2. Their sting is less severe than their reputation suggests.

The Schmidt Pain Index rates the European hornet sting at approximately 2.0 — comparable to a honey bee. Despite the species' large size and intimidating appearance, the venom is not particularly potent compared to other vespines. Single stings are unpleasant but not medically serious for non-allergic individuals. The danger is mass stinging during nest defense, not individual sting toxicity.

The Asian giant hornet confusion ("murder hornets")

This section exists because of recent media history, and because customers will continue asking.

**The Asian giant hornet (Vespa mandarinia) and the European hornet (Vespa crabro) are different species.** Both are in the genus Vespa (true hornets), but they are distinct.

• Vespa crabro (European hornet): Established in eastern North America since the 1840s. Not in Texas. Not particularly dangerous. Rarely a pest.
• Vespa mandarinia (Asian giant hornet, "northern giant hornet," "murder hornet"): Detected in Washington state and British Columbia in late 2019. Subject of an intensive eradication program. Officially declared eradicated from the United States by the WSDA and USDA on December 18, 2024.

What actually happened with "murder hornets"

In December 2019, the Washington State Department of Agriculture confirmed the first United States detection of Vespa mandarinia in Whatcom County. A second detection occurred in British Columbia, Canada. DNA analysis suggested two separate introductions from different countries.

Over the following years, WSDA and USDA conducted an intensive eradication program:

• October 2020: First nest located and destroyed (inside a hollow alder tree at a Washington State University facility), using carbon dioxide sedation, vacuum extraction, and sting-proof suits
• August–September 2021: Three additional nests found and destroyed
• 2022: No detections
• 2023: No detections
• 2024: No detections; eradication declared December 18

After three years of zero confirmed detections, the joint WSDA/USDA announcement on December 18, 2024 declared the species eradicated from Washington state and the United States. This was the first successful eradication of an invasive Vespa species in North American history.

Why this matters for Texas

Asian giant hornets were never established in Texas. Despite alarmist social media posts during the 2020 media cycle that suggested broader distribution, the species was confined to a small area of Whatcom County, Washington and adjacent British Columbia. Louisiana State University's AgCenter species page on cicada killers explicitly addresses this: "alarmist social media posts have suggested a much broader distribution" — referring specifically to the false claims about murder hornet presence outside the Pacific Northwest.

Every "giant hornet" sighting in Texas during 2020 and after has been a misidentified native species. The most common candidates:

• **Cicada killer wasp (Sphecius speciosus)** — see fact sheet 10. Large, black-and-yellow, July-August active. By far the most common confusion.
• Mature queen yellowjacket — early spring. Large, black-and-yellow, briefly visible during nest founding.
• Eastern carpenter bee — large, with a yellow thorax. Looks like a giant bumble bee.
• Tarantula hawk — very large, blue-black with orange wings. Distinctive.

If you encounter a "giant hornet" in Texas in 2026, it is essentially certainly one of the above species, not a true Vespa. We are happy to identify any specimen brought to us or photographed clearly.

Risk to humans and pets

If you somehow encounter a European hornet in Texas: low to moderate. Single stings are roughly equivalent to honey bee stings. The species is generally non-aggressive away from the nest, though it can be defensive of nest sites and food sources, sometimes stinging without warning when surprised. Allergic individuals should exercise the standard precautions appropriate to any Hymenoptera sting.

For practical purposes in our service area, the risk from European hornets is essentially zero — there is no established population.

Treatment approach

If a European hornet nest were ever genuinely confirmed in our service area (extremely unlikely), treatment would follow the same approach as for baldfaced hornets in concealed cavities — dust formulation applied through the nest entry point at dusk or dawn, full bee suit with sealed eye protection, 24-48 hour wait period before nest removal, post-treatment monitoring.

For the actual situation we encounter — homeowner reports of "giant hornets" or "European hornets" in San Antonio or Boerne — the correct treatment approach is identification first. Most of the time, what the customer is describing is a native species (cicada killer, paper wasp queen, carpenter bee). The treatment for the actual species present is what we provide. Telling a customer "you have European hornets" when they actually have cicada killers leads to incorrect expectations and ineffective treatment.

Odd, funny, and genuinely true

• European hornets fly at night and crash into windows. People in Pennsylvania and Maryland who keep porch lights on in late summer report sometimes 10 or more European hornets beating themselves against lighted windows. The sound is loud enough to startle people inside, and the force of the attacks gives the impression the hornets are trying to enter the house. They are not — they are simply attracted to the light, like moths.
• They girdle ornamental shrubs. European hornets strip the bark off lilac, dogwood, ash, and other ornamental woody plants to feed on the sap underneath. The effect can kill young plants. This is one of the few American examples of vespid wasps causing direct horticultural damage.
• Asian giant hornets were declared eradicated from the US on December 18, 2024. After five years of monitoring and eradication work, three years of zero detections, and significant media attention, the species is no longer present in North America. The eradication program required coordination across federal, state, and local agencies, plus citizen scientist participation — half of confirmed detections came from public reports.
• The Entomological Society of America has officially renamed the species to "northern giant hornet" in their Common Names of Insects list, moving away from "Asian giant hornet" (geographic) and "murder hornet" (sensational). This change was made in 2022 in part to reduce association of the species with anti-Asian sentiment that surfaced during the 2020 media cycle.
• **A package containing live larvae and pupae of Vespa mandarinia was intercepted at a US port of entry sometime before 2010**, according to USDA entomologist Allen Smith-Pardo. People sometimes ship live wasp larvae for use as food or in traditional medicine — this is illegal but documented to occur. One theory of how the 2019 introduction occurred involves a mated queen overwintering inside a shipping container.
• ***Vespa crabro* has been continuously present in North America for about 185 years** — since the 1840s — without ever becoming a serious pest. This is unusual for an introduced vespid; most introduced wasps become invasive nuisances. The European hornet is a rare counterexample.
• The species was first described by Carl Linnaeus in 1758 in the 10th edition of Systema Naturae — the foundational work of modern biological taxonomy. Vespa crabro is one of the original "type specimens" that anchored Linnaean classification of Hymenoptera.
• **Worker policing in *Vespa crabro***: workers actively destroy eggs that were not laid by their queen. This is unusual among vespines, where most species use queen pheromones to suppress worker reproduction. Lab data show the queen averages 2.31 eggs per day, but only 1.63 cells are constructed per day — meaning excess eggs are being destroyed, primarily by other workers.
• Minerals found in nest walls include titanium, iron, and zirconium — incorporated from soil during paper construction. The nest cement that holds the paper combs together is also water-resistant, allowing nests to survive in damp locations. Average dry weight of a finished nest is about 81 grams (2.85 ounces).
• Asian giant hornet stings are far more dangerous than European hornet stings. The Asian species causes 30–50 deaths annually in Japan, with cases of multiple-organ failure documented. Single stings on the skin are rarely fatal even for V. mandarinia (allergic individuals excepted), but severe envenomation from multiple stings can be lethal. This was the basis for the "murder hornet" label — and it is genuinely warranted for V. mandarinia. It was never warranted for V. crabro.

FAQ hooks (for LuperIQ / SEO)

• Are there European hornets in Texas?
• What's the difference between a European hornet and an Asian giant hornet?
• Are murder hornets in Texas?
• I saw a giant hornet in San Antonio — what was it?
• European hornet vs. cicada killer
• Are European hornets dangerous?
• Has the murder hornet been eradicated?
• What should I do if I see a giant wasp?

Sources consulted for this fact sheet include the European hornet Wikipedia account citing Linnaeus 1758 original description, NC State University Extension on European hornets, Penn State University Extension species fact sheet, the Smith-Pardo et al. 2020 taxonomic revision (Insect Systematics and Diversity), the Akre et al. 1981 USDA Yellowjackets of North America handbook (#552), the Vespa crabro Discover Life account, ScienceDirect's Medical and Veterinary Entomology overview, and the WSDA/USDA December 18, 2024 joint announcement of the eradication of Vespa mandarinia from the United States. Asian giant hornet history reflects the Washington State Department of Agriculture's documented timeline of detections from 2019 through eradication declaration. Murder hornet history coverage draws on HistoryLink's Vespa mandarinia eradication page and APHIS/USDA agency announcements.