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Western Yellowjacket

Vespula pensylvanica

Western yellowjacket queen with yellow and black abdominal markings

Stocky and boldly marked in yellow and black. Often nests in underground cavities and scavenges at outdoor meals. Workers also gather animal food for their larvae. Give nest entrances plenty of room.

Inside the nest

A queen begins the nest in spring. Her first workers take over foraging and help rear the next brood. The paper combs are hidden inside a protective envelope, often in an underground cavity.

Part of the food web

Workers gather animal protein for the larvae, both by hunting and by scavenging. This helps explain why this species is such a familiar visitor around outdoor meals.

Sharing space

Watch for repeated flights into a ground opening without approaching it. Keep food and rubbish covered, and give an active nest plenty of room.

Advice for sharing space with wasps

Learn More

Read the university identification and biology guide

Photograph & license

Western Yellowjacket — Eugene Zelenko. CC BY-SA 4.0. Resized and converted to WebP.

The photograph illustrates this species or group; it was not necessarily taken in Oregon.

Solitary wasp

A solitary wasp has no colony of workers helping raise her young. A female may stock her own nest cells with food, or find a host for her developing offspring. Solitary describes social life; parasitoid describes a feeding strategy. A wasp can be both.

Social wasp

Social wasps share a nest and cooperate in raising young. In yellowjacket and paper wasp colonies, reproductive females lay eggs and workers help feed the brood and maintain the nest. They can defend that nest, so observing a forager is different from approaching a colony.

Non-native Social wasp

This is a social wasp introduced beyond its natural range. In this case the European paper wasp was introduced to North America from Europe, probably hidden in shipping materials. Non-native describes its origin, while social describes colony life.