Are There Brown Recluse Spiders in Minnesota?

Brown recluse spiders don’t live in Minnesota. Only 2 or 3 have ever turned up in the state, and almost certainly they rode in with boxes or furniture.1Ask Extension. Is this a brown recluse spider? So nearly any brown spider you find at home is something else, and the real question is which harmless look-alike it is. The recluse’s fearsome reputation has traveled much farther north than the spider itself.2Bug Squad. The Myth of the Brown Recluse Spider in California

Where Brown Recluses Actually Live

The brown recluse’s home range runs from Kansas east to Kentucky, and from southern Iowa south to Louisiana.3PubMed Central. Tracking a Medically Important Spider: Climate Change, Ecological Niche Modeling, and the Brown Recluse (Loxosceles reclusa) It thins out sharply near the northern edge: unknown in northern Iowa and rare in southern Iowa.4PubMed. Distribution of the brown recluse spider (Araneae: Sicariidae) in Illinois and Iowa Illinois shows the same fade: the spider is common in the south of the state and nearly absent in the northern counties.5PubMed. Distribution of the brown recluse spider (Araneae: Sicariidae) in Illinois and Iowa Minnesota lies north of southern Iowa, where the spider is already rare, which puts it well past the zone where a resident population is plausible.

The few recluses found around Chicago are thought to have been carried there by people, not to have come from local populations.6PubMed. Distribution of the brown recluse spider (Araneae: Sicariidae) in Illinois and Iowa A spider can arrive in boxes or furniture, but these arrivals seldom start a lasting infestation.7University of Kentucky College of Agriculture. Brown Recluse Spider A lone traveler usually never meets a mate, so a population rarely forms.

Why Minnesota Winters Matter

Brown recluses held at freezing for a month survived, but only 30% lived through a month at 28°F, and none survived a month at 23°F.8The Journal of Arachnology. Cold temperature tolerance and distribution of the brown recluse spider Loxosceles reclusa (Araneae, Sicariidae) in Illinois In short 4-hour cold snaps, about half died at 19°F and all died at 7°F.9The Journal of Arachnology. Cold temperature tolerance and distribution of the brown recluse spider Loxosceles reclusa (Araneae, Sicariidae) in Illinois A Minnesota winter outdoors is far colder and longer than what they can endure. They do live mainly inside buildings, though, which shelter them from winter.10Kansas State University Research and Extension. Brown Recluse Spiders

A heated house doesn’t fully solve the problem for them. To spread to another building on its own, a spider has to cross outdoor ground, and that exposes it to the cold that kills it. Garages, sheds, and other outbuildings aren’t reliably heated and drop to deadly temperatures in a Minnesota winter. A spider that survives inside one warm home would stay confined to that building instead of founding a wider population.

Many species’ ranges are already moving away from the equator as the climate warms, and venomous spiders are expected to shift into cooler zones where more people live.11PubMed. Potential Environmental and Ecological Effects of Global Climate Change on Venomous Terrestrial Species in the Wilderness No established Minnesota population exists today, though.12States Wildlife. Minnesota Spiders: Identification, Pictures & Which Bite

How to Tell a Brown Recluse From Other Brown Spiders

A real recluse has the whole set of these features:

Some other spiders share a few of these features, so check for the whole set.20Spider Research. How to Identify and Misidentify a Brown Recluse Spider Many harmless brown spiders have dark patterns on the back that look violin-like, so eye count is the more dependable check.

You never need to handle the spider to check. Trap it under a clear jar or glass, or examine a dead one. A phone camera zoomed in, or a magnifying glass, can make the eyes visible. Most spiders have eight eyes, so counting eight rules out a recluse, though six eyes alone doesn’t confirm one, since some other spiders also have six.

Brown Spiders in Minnesota Often Mistaken for Recluses

Most reported Minnesota sightings turned out to be other brown spiders.21USA Spiders. Spiders in Minnesota Many harmless spiders share the recluse’s color and size,22Orkin. What Spiders Look Like a Brown Recluse? and wolf spiders are among the most commonly confused.23Rottler Pest Solutions. Wolf Spider vs. Brown Recluse: How to Tell the Difference

Wolf spiders are usually larger and sturdier than a recluse, often hairy, with striped or mottled bodies. They typically run across floors in the open instead of waiting in a web, while recluses hide. Their eyes include two large ones facing forward, unlike the recluse’s six similar-sized eyes in pairs.

Parson spiders hunt fast at night and hide under objects or in cracks indoors.24University of Minnesota Extension. Spiders Like recluses, they can bite if trapped in clothing or bedding.25University of Minnesota Extension. Spiders The bite is painful and may cause an allergic reaction in some people, but it is not a recluse-type wound.26University of Minnesota Extension. Spiders

If you can’t settle an identification yourself, University of Minnesota Extension can identify spiders from photos or specimens, which is more reliable than guessing from a web search. For a photo, shoot clearly from above so the legs and the back pattern are both visible. To send a specimen, keep it in rubbing alcohol in a sealed jar so it stays intact.

If You Have a Wound That Looks Like a Spider Bite

Recluse venom can kill skin tissue and leave an open sore.27PubMed. Interaction of brown recluse spider venom on cell membranes: the inciting mechanism? But worldwide, wounds with dying skin are regularly blamed on spiders without good evidence.28Canadian Family Physician. An approach to spider bites: Erroneous attribution of dermonecrotic lesions to brown recluse or hobo spider bites in Canada In most reported bites outside the spider’s range, no spider was ever caught or identified.29PubMed. Reports of presumptive brown recluse spider bites reinforce improbable diagnosis in regions of North America where the spider is not endemic A recluse bite diagnosed in Minnesota is very likely wrong.30PubMed. Reports of presumptive brown recluse spider bites reinforce improbable diagnosis in regions of North America where the spider is not endemic

Skin infections, including MRSA, are a frequent real cause of painful sores that get blamed on spiders. Allergic reactions and some chronic skin conditions can also produce red, swollen, or ulcerating lesions. Treatment differs widely between these causes, so naming the wrong one can delay the care that’s needed. Many of the conditions mistaken for recluse bites can be fatal or disabling.31PubMed. Reports of presumptive brown recluse spider bites reinforce improbable diagnosis in regions of North America where the spider is not endemic A spreading or worsening sore needs a doctor’s diagnosis, not a spider label.

At the appointment, say honestly whether you saw a spider bite you or only found the sore later, because that changes how likely a bite is. Mention any recent travel to, or moves from, southern states where recluses live. Report fever, spreading redness, or pus right away, since these can signal an infection needing prompt treatment.

Why the Fear Outpaces the Spider

Searches for brown recluse rise after news of spider encounters, especially sensational stories.32PubMed Central. The influence of spider news on online information-seeking Yet hospitalizations from these spiders are extremely rare.33PubMed Central. The influence of spider news on online information-seeking Overstated spider bite stories are also shared more on social media.34People and Nature. Media framing of spiders may exacerbate arachnophobic sentiments So the belief persists even in places like California, where there are no recluses at all.35Bug Squad. The Myth of the Brown Recluse Spider in California Panic can lead people to spray pesticides they don’t need, and most house spiders are harmless and eat other household pests.

What to Do If You Find a Suspected Recluse

Brown recluses are not aggressive. They bite mainly when pressed against skin.36University of Kentucky College of Agriculture. Brown Recluse Spider That happens when someone rolls onto one in bed, handles stored items, or puts on rarely worn clothes or shoes.37U.S. Army Medical Department. Environmental Science Section – Insect and Wildlife Shaking out stored clothing and shoes is sensible, especially items from boxes you moved. Start by saving the spider in a jar and getting an expert identification before calling an exterminator, since most finds are not recluses.

If a recluse is confirmed, place sticky traps along walls and in closets to see whether more show up. Traps alone don’t reduce an infestation,38Journal of the Kansas Entomological Society. Residual Effect of Insecticide Treatment Plus Use of Sticky Traps on Brown Recluse Spiders (Araneae: Sicariidae) on Two Surfaces but traps plus one insecticide treatment lowered spider numbers over 4 weeks.39Journal of the Kansas Entomological Society. Residual Effect of Insecticide Treatment Plus Use of Sticky Traps on Brown Recluse Spiders (Araneae: Sicariidae) on Two Surfaces The spiders are also hard to kill, needing very high fumigation doses.40NeoBiota. Assessing ongoing risks and managing detections of non-native invertebrates in the Antarctic Region

To cut down on hiding places, store items in sealed plastic bins instead of cardboard, which gives spiders easy cover. Keep clothes and shoes off the floor. Pull beds away from walls and keep bedding off the floor so spiders can’t climb up into it.