What bit me in South Dakota?

13 biting or stinging species have verified records in South Dakota. 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 May to September.

Active around now in South Dakota

Recorded biting species in South Dakota

SpeciesLooks likeWhere on bodyRecordsPeak
Honey bee sting single feet — bees are often stepped on in clover, hands 413 May to August
American dog tick bite single scalp, neck 104 April to July
Paper wasp sting usually single hands, head 44 May to August
Carpenter ant bite single or a few hands, arms 32 May to August
Horsefly bite single, occasionally two legs, back 21 June to September
Bald-faced hornet sting often several — the colony defends aggressively head, neck 15 July to October
Flea bite clusters of three or four, or short irregular groups ankles, shins 14 June, August, September, October
Chigger bite clusters concentrated where clothing is tight ankles, behind the knees 12 May, July, August, September
Yellowjacket sting single or several — this wasp can sting repeatedly hands, face 11 August to October
Wolf spider bite single site hands, feet 10 May, June, September, October
Bed bug bite lines or zigzags of three or more — the classic "breakfast, lunch and dinner" arms, shoulders 4 July
Deer tick bite single, usually in a skin fold or hairline groin, armpits 3 April to July
Lone star tick bite single, sometimes dozens at once when larval "seed ticks" swarm legs, waist 3 April to July

Record counts come from the GBIF biodiversity database and reflect how often a species is reported and identified in South Dakota. 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 13 species recorded in South Dakota, 13 are active in June — the peak of the local season. The continental 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.

MonthSpecies activeNotably
January 1 Bed bug
February 1 Bed bug
March 4 Honey bee, Flea, Bed bug
April 8 Honey bee, American dog tick, Carpenter ant
May 11 Honey bee, American dog tick, Paper wasp
June 13 Honey bee, American dog tick, Paper wasp
July 13 Honey bee, American dog tick, Paper wasp
August 13 Honey bee, American dog tick, Paper wasp
September 12 Honey bee, Paper wasp, Carpenter ant
October 7 Honey bee, Bald-faced hornet, Flea
November 2 Flea, Bed bug
December 1 Bed bug

Narrowing it down in three questions

  1. 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.
  2. 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.
  3. 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 South Dakota the outdoor season runs May to September; the indoor species run all year.

Stings rather than bites in South Dakota

Honey bee, Paper wasp, Carpenter ant, Bald-faced hornet, Yellowjacket 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

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 South Dakota

Weather does not affect everything. Bed bugs, scabies and head lice depend on people rather than season, so a bite pattern in January in South Dakota 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.

Download for iPhone — free

iPhone and iPad. Free to download.