What bit me in Oregon?
11 biting or stinging species have verified records in Oregon. The fastest way to narrow it down is where on your body the marks are and how they are arranged — below the knee in clusters points to fleas or chiggers, lines on uncovered skin point to bed bugs, scattered single bumps point to mosquitoes. Bite season here runs roughly April to October.
Active around now in Oregon
- Honey bee
- Paper wasp
- Bald-faced hornet
- American dog tick
- Yellow sac spider
- Yellowjacket
- Flea
- Mosquito
- Bed bug
- Head lice bites
Recorded biting species in Oregon
| Species | Looks like | Where on body | Records | Peak |
|---|---|---|---|---|
| Honey bee sting | single | feet — bees are often stepped on in clover, hands | 5,894 | May to August |
| Paper wasp sting | usually single | hands, head | 1,638 | April, May, July, August |
| Bald-faced hornet sting | often several — the colony defends aggressively | head, neck | 753 | July to October |
| American dog tick bite | single | scalp, neck | 72 | April to July |
| Yellow sac spider bite | single, sometimes two nearby | neck, arms | 66 | April, May, October |
| Yellowjacket sting | single or several — this wasp can sting repeatedly | hands, face | 17 | August to October |
| Flea bite | clusters of three or four, or short irregular groups | ankles, shins | 14 | June, August, September, October |
| Mosquito bite | single bumps scattered over exposed skin | ankles, lower legs | 8 | June to September |
| Bed bug bite | lines or zigzags of three or more — the classic "breakfast, lunch and dinner" | arms, shoulders | 8 | July |
| Head lice bites | concentrated behind the ears and at the nape | scalp, behind the ears | 6 | July |
| Carpenter ant bite | single or a few | hands, arms | 5 | April to July |
Record counts come from the GBIF biodiversity database and reflect how often a species is reported and identified in Oregon. They are a guide to what is plausible here, not a census — and they say nothing about how likely you are to be bitten indoors.
Bite season month by month
Of the 11 species recorded in Oregon, 11 are active in June — the peak of the local season. The oceanic to semi-arid climate here is what sets those boundaries: species that need warmth disappear at the edges of the year, while the indoor ones do not care.
| Month | Species active | Notably |
|---|---|---|
| January | 2 | Bed bug, Head lice bites |
| February | 2 | Bed bug, Head lice bites |
| March | 4 | Honey bee, Flea, Bed bug |
| April | 8 | Honey bee, American dog tick, Yellow sac spider |
| May | 9 | Honey bee, Paper wasp, American dog tick |
| June | 11 | Honey bee, Paper wasp, Bald-faced hornet |
| July | 11 | Honey bee, Paper wasp, Bald-faced hornet |
| August | 11 | Honey bee, Paper wasp, Bald-faced hornet |
| September | 10 | Honey bee, Paper wasp, Bald-faced hornet |
| October | 8 | Honey bee, Bald-faced hornet, Yellow sac spider |
| November | 4 | Yellow sac spider, Flea, Bed bug |
| December | 2 | Bed bug, Head lice bites |
Narrowing it down in three questions
- Where on your body? Below the knee in clusters points to fleas or chiggers. Uncovered skin — arms, shoulders, neck — points to bed bugs or mosquitoes. Along a sock line or waistband is close to diagnostic for chiggers.
- How are they arranged? A line or zigzag of three or more suggests bed bugs. Scattered single bumps suggest mosquitoes. A curved group with white pustules the next day means fire ants.
- Indoors or outdoors, and when? Bites that appear overnight in one specific bed are a different problem from bites after an afternoon in tall grass. In Oregon the outdoor season runs April to October; the indoor species run all year.
Stings rather than bites in Oregon
Honey bee, Paper wasp, Bald-faced hornet, Yellowjacket, Carpenter ant are recorded here. Stings differ from bites in one way that matters: they can cause anaphylaxis in sensitised people, and that risk does not depend on how bad previous stings looked. Anyone who has had a severe reaction should carry an adrenaline auto-injector.
Species associated with illness here
- American dog tick bite — Rocky Mountain spotted fever, tularemia, tick paralysis (rare, resolves on removal)
- Flea bite — murine typhus (Gulf Coast, California, Hawaii), cat scratch disease bacteria carried between cats, flea tapeworm (mainly in children who swallow a flea)
- Mosquito bite — West Nile virus, La Crosse encephalitis, dengue (Gulf Coast and Southwest, local cases), chikungunya (rare, travel-linked)
Most bites from these species transmit nothing. What matters is the follow-up: note the date of the bite, and report any fever or expanding rash in the following weeks to a clinician, mentioning the bite explicitly.
Seek medical care if
Call emergency services now for difficulty breathing, swelling of the lips, tongue or throat, dizziness or fainting, or hives spreading away from the bite.
- difficulty breathing, or swelling of the lips, tongue or throat after a sting
- a red area that is spreading, hot and painful, especially with a red streak
- fever, chills or feeling generally unwell in the days or weeks after a bite
- an expanding rash appearing 3 to 30 days after a tick bite
- a bite that is getting worse rather than better after 72 hours
Year-round in Oregon
Weather does not affect everything. Bed bugs, scabies and head lice depend on people rather than season, so a bite pattern in January in Oregon points to those first — see what is biting me at night.
Get a photo assessment in the app
Everything above is free to read. The app adds what a page cannot: point your camera at the bite and get an assessment of the most likely cause, a severity read, and a day-by-day care plan — including the specific signs that mean you should be seen.
iPhone and iPad. Free to download.