Bug FAQWestern Paper Wasp
Mischocyttarus flavitarsis · Order: Hymenoptera · Family: Vespidae
Also called: Wasp, Yellow-legged Paper Wasp
Western Paper Wasps are brownish paper wasps found from southern California to British Columbia, often nesting under eaves or near rivers. They feed adults on nectar and bring captured flies and caterpillars to their larvae, and their colonies run from before May until October.
Source: Wikipedia
How to recognize it
Their bodies are generally brownish in color.
Source: Wikipedia
Size
Paper wasps have long, slender bodies with trailing hind legs.
Source: Wikipedia
Is it a pest in the house?
They often nest in built environments like wall voids and under eaves, close to human activity.
Source: Wikipedia
Does it bite or sting?
When threatened they usually do not sting; instead they ram at the intruder while raising their legs and antennae.
Source: Wikipedia
Where it lives
They live in western North America, from southern California up to British Columbia. Nests are built in forests near rivers or in human structures such as under roof eaves.
Source: Wikipedia
What it eats
Adults drink nectar, while they hunt flies and caterpillars to feed their larvae.
Source: Wikipedia
Life cycle
Colonies start before May and continue until October, after which the queen seeks a hibernation site.
Source: Wikipedia
When you see it
Colony activity runs from early spring to fall, with mating in September and October.
Source: Wikipedia
Where it comes from
Mischocyttarus flavitarsis is a social paper wasp native to western North America.
Source: Wikipedia
Where it is found in the US
Recorded in 14 of 51 states and DC. Most records: California, Colorado, Utah, New Mexico, Oregon, Washington, Texas, Arizona.
Darker = more records. Counts are museum and citizen-science records, not population size.
Source: GBIF
Status: native in North America; native in Canada; native in United States. Source: iNaturalist
Months it is reported in the US
Source: GBIF
More photos
Questions people ask
Do they sting people?
No, they typically do not sting; they will ram at a threat instead.
Source: Wikipedia
Where do Western Paper Wasps build their nests?
They nest in forest areas near rivers and in human structures such as under roof eaves or in wall voids.
Source: Wikipedia
What do they eat?
Adults drink nectar, and they capture flies and caterpillars to feed their larvae.
Source: Wikipedia
When are they active?
Their colonies are active from before May through October, with mating in September and October.
Source: Wikipedia
Same family (Vespidae)
Sources
- Wikipedia: https://en.wikipedia.org/wiki/Mischocyttarus_flavitarsis
Look it up elsewhere: GBIF · iNaturalist · BugGuide · Wikipedia
Text written 2026-10-23 from the sources above and checked sentence by sentence against them. Data fetched 2026-10-22.