It’s understandable that interest in wasps among the human population often starts with the stinging wasps. Fortunately, a very small percentage of Oregon wasps are considered dangerous stinging wasps. They typically belong to the family Vespidae, commonly known as yellowjackets, paper wasps and hornets. Conversations about paper wasps changes slightly between the Eastern and Western United States. Easterners focus on species in the Polistes genus. Westerners add two additional types of species, pollen wasps and Mischocyttarus. The video at the top of the page shows a pollen wasp. Surprise, it’s a vegetarian wasp, meaning it feeds its larvae pollen rather than insects. The clubbed antenna are a good field identification clue.
Mischocyttarus actuallyrank as the world’s largest genus of social paper wasps, with around 250 species. They are primarily a subtropical species, with only three species documented in the United States. The Western Paper Wasp is the most widespread, found in states west of the Midwest. The Mexican paper was is found in Texas and the Southeast Gulf Coast states. The Najavo is found only in Arizona.
Chances are that visitors to this page have seen the paper wasp in the picture. It’s a European paper wasp, a recent import that aggressively spread its range from the East Coast to the back yards of many Oregon homes. The two dots on the top of the thorax are good field identification clues.
Western Yellowjacket They usually build ground nests. However, they can also build nests in open spaces in walls or beneath the home. In these instances, it’s a good idea to call a professional pest control company. Look for a black anchor mark on the top of the abdomen as the best field identification clue.
Potter and Mason wasps also fit into the Vespidae family, and by a wide margin, they are the most common in terms of number of species. Anywhere from four to five dozen species fly around the state during the season. They get their common nick name because some will dig into the mortar between the bricks. Others build ground nests. Consider them more beneficial than pest insects because while they might sting if disturbed, their solitary nature means that unlike their relative the yellowjackets and paper wasps, they don’t attack in large numbers.
Some are easier to identify than others due to the presence of a constricted abdominal part that links the thorax and abdomen. For example, the potter wasp in the picture belongs to the Eumenes genus.
The remaining species generally have black bodies with either yellow or white markings. They grow to about one-half inch in length.
More Oregon Wasps
The common name Carrot Wasp refers to the fact that plants in the carrot family are the adults favorite nectar flowers. Formally there is only one genus in the family. It’s a parasitic wasp that gets placed in the catch all parasitic wasp category, parasitoid Apocrita.
Braconid and Ichneumonid Wasps are related and have a similar thin look. The flat square at the bottom of the last set of legs is a good field ID for Carrot Wasps. Not seen in the picture is the elongated neck. It’s the deposits its eggs in the nests of other wasps.
Thread-waisted Wasps (Family Sphecidae) rank among the easiest of the Oregon wasps to identify. They divide into common names such as Ammophila, digger wasps and mud-daubers. Up first is an Ammophila wasp. Note the long thin body. With over sixty species across the country, it’s difficult to identify any one species.
Here’s a bit of muddying up the identification waters when it comes to Oregon wasps. The Cutworm wasp in the picture is related to the Ammophila, but a separate genus, Podalonia. It looks very similar to the preceding Ammophila species. Looking closely finds that the thin waist tilts up when it gets to the abdomen. That’s the best field identification clue.
A quick move away from thread-waisted wasps with the next picture shows another wasp with black thorax and red abdomen. It’s a popular combination for many wasp species. The first thing to note is that the lack of a thread-waist moves it into another wasp family. Given the distinct separation of the abdominal segments with the last segment showing a black spot, the tentative identification is a spider wasp truly at home in Oregon with the formal name, Priocnemis oregona.
Prionychini 17 spp. in 2 genera Prionyx
Back to thread-waisted Wasps and the next picture shows an all red species that belongs to the Prionyx genus. They are smaller than the digger wasps and mud-daubers, and they often show up in gardens during the summer months.
The Great Golden Digger Wasp’s (Sphex ichneumoneus) continental range, all other Sphex species limit their range to specific geographical areas. The Great Black Digger Wasp, pictured, comes in second in terms of range.
A word of caution with respect to identification. A few wasps, especially some grassy carrying wasps, also have all black bodies. The Great Black Digger Wasp tends to fold its wings down along the body as it nectars on flowers. Grass Carrying wasps tend to spread their wings at an angle while they nectar on flowers.
They sting, but they are not aggressive.
The Crabronidae family consists of many familiar wasps with common names such as sand wasps, beewolves and square headed wasps. They are related to bees, except of course for the fact that bees evolved to be vegetarians and the wasps in this family prey on other insects. The quick overview shows some basic physical characteristics of species from different subfamilies.
Up first are the Sand wasps (Tribe Bembicini). They tend to be colorful, medium sized wasps with distinct eyes. making them easy to spot as they nectar on flowers or dig along the ground nest building. Many of the species prey on flies, so they definitely can be considered beneficial insects around the home.
American Sand Wasps (Bembix americana) are a common species in residential areas across much of the northern half of the United States. Jagged edges on the abdominal bands plus the green eyes serve as initial identification clues.
Comparing Beewolves, Square-headed Wasps and Weevil Wasps begins by noting many tend to have black bodies with yellow patterns. The rough looking body with small pits on it are good initial field identification clues for Beewolves.
The common name Square-headed wasps refers to the shape of the head. Otherwise the wasp in the picture looks very similar to the thousands of other small wasps with black bodies and yellow stripes. A close look also reveals antennae that are yellow on the bottom and black on the top. That’s another good field identification clue.