Monday, April 26, 2021

Answers to common questions about WSDA's proposed hornet quarantine

Amy Clow
WSDA Pest Program 

The Washington State Department of Agriculture (WSDA) is proposing to add all species in the genus Vespa (hornet) to the list of quarantined pests. The rule we are proposing would prohibit live life stages of hornet species from being sold, offered for sale, distributed, or knowingly moved throughout or received within Washington.

The proposal adds restrictions to “infested sites,” defined as all property within 20 meters of a nest containing any live life stage of hornet.

The Black Bellied hornet

WSDA will try to notify occupants or owners when their property is designated as an infested site. Until WSDA determines an area is not infested, people will need to get authorization to enter the area. This is to protect the public and prevent more infestation. The proposed rule would allow WSDA to grant access to an infested site to property owners, occupants, and others.

Some frequently asked questions

If a nest is detected on private property, will the owner or occupant be restricted from accessing or entering their property?

No. Access to property owners and occupants will not be restricted. Restricting access within a 20 meter area around the nest is a precaution to protect public health and safety, prevent further infestation, and ensure the nest is safely removed.

WSDA will remove the nest as soon as possible. Nest removal depends on the situation and factors such as weather, obstructions, and equipment availability. Generally, removal will take no longer than two weeks. 

Will yellowjackets or bald-faced hornets be included in the quarantine?

No. Yellowjackets and bald-faced hornets are not included in the proposed quarantine. Yellowjackets belong to the genus Vespula and Dolichovespula. Bald-faced hornets (Dolichovespula maculata) are a type of yellowjacket and not a true hornet (Vespa).

Why are all hornets being quarantined rather than only Asian giant hornet?

No hornet species are native to Washington State. Any hornet introduced here could upset our state’s ecosystem, such as spreading new pathogens and parasites to native wasps, bees, and yellowjackets. Washington’s suitable habitat for certain hornet species make it more likely they will become established once introduced.

Asian giant hornets on a notebook.
The recent detection of Asian giant hornet caught the attention of Washington state residents, but that’s only one reason for the proposed rule. It’s also needed because other hornet species have been detected in Washington and neighboring British Columbia (Vespa orientalis, Vespa soror, and Vespa crabro).

What risk do hornets actually pose?

Hornets pose a direct and indirect risk to agricultural crops in Washington State. They have been known to feed on fruit such as pears, peaches, plums, grapes, berries, and apples, making the fruit unfit for human consumption. Hornets attack honey bees and native insect populations. Managed honey bees and native insects are important pollinators vital to agricultural production. If hornets were to become established in Washington, our economy and ecology could be severely affected.

Hornets can also pose a risk to human health. The venom in their sting can be toxic. And unlike bees, they can sting repeatedly. A hornet sting can cause substantial pain, as well as tissue damage. In some extremely rare cases, death can also occur. Although hornets don’t generally target people, they can attack when threatened.

Visit for more information on the Asian giant hornet, or the WSDA rulemaking page for information on the proposed hornet quarantine rule.