Hornet Trapping

If you do not live in Washington State, please do not participate in WSDA's citizen scientist trapping. Please seek guidance about trapping for northern giant hornets in your area from your own state’s or province's department of agriculture.

Trapping for 2024 will start July 1. Check out the instructions below to see what supplies you'll need to be ready to go.

Also check out our new Watch a Wasp Next Program program for another way to help the cause starting in June! 

In order for trapping to be successful, those who participate should know that trapping is a commitment. It will require you to:

• obtain materials to build and maintain traps
• log your traps on WSDA's online mapping system
• check your traps weekly for 22 weeks starting in July and continuing through November
• submit any catches of northern giant hornets to WSDA

There is a video that demonstrates how to make the traps if you would like to watch a demonstration. 

Thank you for your interest in assisting in trapping for northern giant hornets, which pose a serious threat to honey bees, other insects, and even humans. By participating in trapping, and reporting the results to WSDA, you can help us understand and limit the spread and possibly even eradicate these invasive hornets from Washington State. 

Although we invite anyone in Washington to participate in trapping, we are particularly interested in trapping information from Whatcom, Skagit, Island, San Juan, Snohomish, King, Jefferson and Clallam counties. 

Please do not start trapping in July, when worker hornets become active. Given that we believe the numbers of queens are very low, trapping before July is unlikely to catch a queen but will unnecessarily catch and kill local insects. 

In addition to the bottle trap instructions detailed on this page, you can also download a printable copy of the trapping instructions using the button below. 

The trap in these instructions is known as a "bottle trap" and targets Northern giant hornet workers in the summer and fall.  

You will need enough materials for 22 weeks of trapping beginning in July and ending in November. WSDA has previously used orange juice and rice cooking wine, but an alternative trap option is available. Below is what you will need for each trap for the season.

Materials

Below are the materials you will need for one trap for an entire season of trapping from July through November (22 weeks). 

• 2-liter or 64-ounce plastic bottle
• Box cutter
• String or twine
• Orange juice (100% juice, no pulp, with few additives) - 22 4-ounce juice boxes
• Rice cooking wine (10-25% alcohol content) 88 ounces or 4 25-ounce bottles
• Container for sorting 
• Strainer

Alternate trap

• 2-liter or 64-ounce plastic bottle
• Box cutter
• String or twine
• 11 cups/88oz dark brown sugar
• 11 cups/88oz water
• Container for sorting 
• Strainer

Prepare the bottle

Near the top 1/3 of the bottle draw a horizontal 2 cm (0.78 inch) line on the bottle.


Draw a vertical 1 cm (0.39 in) above and below each end of the horizontal line. You will have an H, repeat on reamaining 2 sides.

Using the box cutter, very carefully cut along the three lines, creating tabs.


Carefully fold and push the tabs inward.

Repeat the drawing and cutting of the shapes on two more sides of the bottle, so that three sides total on the bottle have the H-shaped opening. 

Baiting the traps

OJ/Rice wine bait

Rice cooking wine will discourage honey bees from visiting the trap. Ensure that the alcohol content is between 10% and 25% by volume. Rice cooking wine can be found at most grocery stores. While more expensive, sake can also be used. Examples of rice cooking wine and what to look for: 

  

Prepare the bait - OJ trap

1. Remove the cap
2. Pour 4 ounces (½ cup) of rice cooking wine into the bottle
3. Add 4 ounces (½ cup) of orange juice
4. Replace cap
5. Tie string around the neck of the bottle

 

Prepare the bait - brown sugar trap

1. Remove the cap
2. Pour 8 ounces (1 cup) of dark brown sugar
3. Add 8 ounces (1 cup) of water
4. Stir to disolve the sugar somewhat
5. Replace cap
6. Tie string around the neck of the bottle

Hang the bottle at least 6 feet high on trees near forest edges, if possible. Do not hang bottles higher than 9 feet. If hanging more than one trap, traps should be at least 50 feet apart. Unless you are in a target county (Whatcom, Skagit, San Juan, Island, Jefferson, or Clallam) there is no need to place more than one trap on your property. 

Affix a sturdy string or wire around the neck of the bottle. Hang the trap on a sturdy branch so the closed side of the bottle faces the tree.

Only place traps on your own property or property that you have permission to access. 

  

Visit WSDA's Map a Trap webpage to log the location of your trap(s). You can also see where other citizen scientists are trapping.

1. Follow the instructions on the map and obtain your trap number. 
2. Write the trap number the map provides on your bottle trap.
3. Remember to create a new pin and get a trap number for each trap you hang.

Please note: If you find a live northern giant hornet in your trap when you check it - do not handle the trap. Contact WSDA immediately at 1-800-443-6684.

Every week, collect a sample and replace the bait. This should be 22 services. Bait should be replaced every week even if no hornets are captured.

1. Remove the trap each week.
2. Pour the trap contents into a strainer.
3. Rinse the collection with water to clean it.
4. Empty the contents into the storage container.
5. Refill the bottle with the bait mixture.
6. Rehang your bottle trap.

Sort through your rinsed trap collection and look for insects that appear to be northern giant hornets, which can be anywhere from 1-2 inches long. If you aren't sure, snap a picture and report it. 

You only need to report catches of suspected hornets. If you suspect you have caught one in your trap collection, take a photo and email it, along with the date and trap number, to hornets@agr.wa.gov. Keep the specimen until WSDA confirms your find and provides further instruction. You can also call 1-800-443-6684. 


Don't let the color fool you! Northern giant hornets can have yellow to orange coloring and can become discolored from the bait and appear darker than when they were alive. 

Below are the results from the 2020 citizen science trapping program, when participants were asked to submit everything caught in the trap. Participants no longer send in specimens since it was determined that they traps were not having and substantial unintended consequences. There is no 2021 data as the trap contents were not collected after 2020. 

Join our Washington State Hornet Watch Facebook group to stay up-to-date on hornet activities. 

Email WSDA's Pest Program with questions about trapping for hornets at hornets@agr.wa.gov.

Join our email distribution list (be sure to select the box next to Asian giant hornet when you sign up.)