Brown Recluse and Black Widow Spiders in Wisconsin - Bite Info and Safety Tips

Exploring Wisconsin's Most Notorious Arachnids

Wisconsin is home to a diverse array of spider species, most of which are harmless to humans. However, the state harbors two types of spiders with notorious reputations - the brown recluse and black widow.

While spider bites are uncommon, both species can inflict painful bites that in rare cases, can become medically significant. Understanding how to identify them and prevent bites is key to enjoying Wisconsin's outdoors safely.

The Timid But Venomous Brown Recluse Spider

Perhaps Wisconsin's most feared homegrown spider is the brown recluse, Loxosceles reclusa. This shy, retiring species earns its name from its secretive nocturnal habits and preference for remote, undisturbed spaces.

Brown recluse spiders are not aggressive and in fact, cannot bite through clothing. But if threatened, they will bite in self-defense. And while uncommon, their venom can cause severe reactions in some people.

Identifying Features of the Brown Recluse

Key identification features of this spider include:

• Uniform sandy brown body and legs
• Dark brown violin-shaped marking on the cephalothorax (body section)
• Long, thin legs with no spines
• Three pairs of eyes arranged in a semicircle
• Body size around 1/4 to 3/4 inch

Brown Recluse Bites and Symptoms

Most brown recluse bites produce mild symptoms like redness, itching, and swelling near the bite. Often the bite goes unnoticed initially.

In more severe cases, their hemotoxic venom can trigger extensive skin and tissue damage resulting in a painful lesion called necrosis. Fever, chills, and vomiting may also occur.

Seeking prompt medical treatment is vital, as necrosis can spread through underlying tissues in extreme cases. Deaths are very rare.

Brown Recluse Habitats in Wisconsin

Brown recluse spiders occupy mostly southern Wisconsin, with isolated populations reported as far north as central Wisconsin. Within their range, common habitats include:

• Attics
• Basements
• Sheds
• Barns
• Wood piles
• Tree hollows
• Undisturbed storage areas

Wisconsin's Black Widow Spiders

The infamous black widow spider maintains an even more lethal reputation than the brown recluse in North America. Often considered the most venomous spider in the United States, black widows can inflict extremely painful and medically significant bites.

Identifying the Black Widow Spider

Female black widow spiders, the only sex known to bite humans, are easily identified by:

• Shiny black body and long black legs
• Prominent red or orange hourglass marking on the underside
• Body size ranging from 1/4 inch to over 1 inch
• Round spiny egg sacs made of thick silk

Males are smaller, brownish, and harmless.

Venom Effects and Bite Treatment

The neurotoxic venom of female black widows can trigger severe muscle cramps, abdominal pain, and hypertension in humans. Though rare, severe untreated cases can potentially lead to dangerous rises in blood pressure, respiratory distress, or paralysis. But prompt medical care has made fatalities extremely unlikely. While their bites inspire fear, black widows are non-aggressive and bite only in self-defense or accidental contact. Still, caution is warranted in their habitats.

Where to Find Black Widows in Wisconsin

Black widow spiders reside primarily in southern Wisconsin, with isolated northern populations found mainly in buildings. Prime habitats statewide include:

• Wood piles
• Tree stumps
• Compost bins
• Outdoor toilets
• Shed interiors
• Undersides of lawn furniture
• Corners of unused garages or barns

Avoiding Spider Bites in Wisconsin

While brown recluse and black widow spiders command the most concern in Wisconsin, dozens of harmless species also reside in the state. Exercising sensible precautions in areas these spiders occupy can greatly reduce any risks. Useful bite prevention tips include:

Inspect and Declutter Infrequently Used Areas

When cleaning attics, basements and sheds that have remained undisturbed for long periods, wear gloves, long sleeves and pants. Also have a flashlight handy to inspect corners and crevices before reaching in blindly. Remove excess clutter and seal cracks that could harbor spiders.

Use Caution Handling Debris Outdoors

Wear protective clothing like gloves when moving wood piles, tree branches or yard waste. Check items like buckets or debris before placing hands inside. Ensure outdoor play areas, furniture, and structures remain kept free of heavy ground clutter or tall grasses.

Shake Out Shoes, Towels, Clothes

Always shake out any items left on floors or the ground before use. Remember black widows often weave messy irregular webs. So look for both spiders and cobwebs before grabbing items that have sit untouched outside.

Being watchful for spiders and taking sensible precautions can help Wisconsin residents safely co-exist with these misunderstood arthropods that play vital roles in local ecosystems.

Disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult with a healthcare professional before starting any new treatment regimen.