Wasps & Hornets in Oregon

Wasps, Yellowjackets, and Bees are stinging insects that can be both beneficial and harmful depending on the circumstances. It may not always seem like it, but wasps and yellowjackets do serve a purpose and are more beneficial than not. However, when they build nests on or around homes, they can quickly become a hazard.

The Willamette Valley is home to several species of wasps, each with its unique characteristics and behaviors. Here are a few of the most common species you might encounter in the area:

Yellow Jackets: Yellow jackets are a type of social wasp that build their nests in the ground or in wall voids. These insects can be aggressive and will defend their nests. Yellow jackets can sting multiple times, and their stings can be painful and even life-threatening for those with allergies.

We get several species of Yellow Jackets here in Oregon, the most common being the western yellowjacket (Paravespula pensylvanica), the common yellowjacket (Paravespula vulgaris), and the aerial yellowjacket (Dolichovespula arenaria). 

The Common and Western Yellow Jackets will build concealed nests in the ground, at the base of plants, and sometimes even in the walls of structures. They are very quick to sting, particularly when a nest is stepped on or disturbed somehow. Aerial Yellow Jackets build nests that look similar to a hornet’s nest, a paper structure shaped like an oblong sphere. You will usually find these nests in trees or tall bushes, or sometimes hanging from the eaves of your home.

Paper Wasps (European Wasps): Paper wasps are another social wasp species that build their nests in sheltered areas such as eaves, tree branches, and door frames. These insects are less aggressive than yellow jackets, but they can still sting if they feel threatened.

Paper wasps build open-cell nests under eaves and in other protected areas. They look similar to Yellow Jackets, with black and yellow markings, but they are bigger and have longer legs that hang down during flight. They can be aggressive and sting if people get too close to the nest. They are also very sensitive to cold, so if you are going to service or knock down a nest, it is best to do so early in the morning when they’re at rest.

Bald-faced Hornets: Bald-faced hornets are a type of social wasp that build large, aerial nests in trees or on the sides of buildings. These insects are aggressive and will defend their nests vigorously, often stinging multiple times. Bald-faced hornet stings can be very painful and may cause an allergic reaction in some people.

Mud Daubers: Mud daubers are solitary wasps that build their nests out of mud. These insects are typically not aggressive and rarely sting people, or cannot sting at all sometimes. Mud daubers are beneficial insects as they prey on spiders and other insects, so they should be left alone if possible. Once the mud nests are abandoned, they can be easily removed.