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Wasps & Hornets in Delaware
Yellowjackets get aggressive in late summer. Don’t disturb ground nests.
| Peak season | Aug – Sep |
|---|---|
| Size | 1/2 – 1 1/2 inches |
| Risk | Health — painful stings, allergic reactions |
| Who treats it | Mosquito & Pest Authority (sponsor) |
How to identify them
Yellowjackets are black and yellow and nest in the ground or walls. Paper wasps build open umbrella-shaped nests under eaves. Bald-faced hornets build large gray paper nests in trees.
Wasps & Hornets in Delaware
Colonies peak in late summer, when yellowjackets crowd picnics and trash cans and defend ground nests near lawns and gardens.
When they’re active
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What you can do now
- Knock down small paper wasp nests early in spring.
- Keep trash and drinks covered outdoors.
- Never seal or pour liquids into a ground nest.
When to call a pro
Call a pro for ground nests, nests in walls, large hornet nests, or anyone with a sting allergy.
Wasps & Hornets: common questions
Should I remove a wasp nest myself?
Small paper wasp nests can sometimes be handled early in spring, but ground nests, wall nests and large hornet nests are better left to a pro. Never seal or pour liquids into a ground nest.
Why are yellowjackets worse in late summer?
Colonies are at their largest in late summer, and the workers are looking for sweet drinks and food. Keeping trash and drinks covered outdoors helps.
What if someone in my family is allergic to stings?
Talk to your doctor about a plan, and keep away from nests. If anyone has a sting allergy, call a professional rather than attempting removal.
Where in Delaware
Where wasps & hornets rank on each county’s top-pest list:
- New Castle County Not in the county top six
- Kent County Not in the county top six
- Sussex County Not in the county top six
Towns where wasps & hornets are on the local top-pest list: