A Guide to Red Spiders Found in Wisconsin | Spider Identification

Red Spiders Commonly Found in Wisconsin

Wisconsin is home to a diverse array of spider species, some of which have reddish coloring. While the large majority of spiders are not dangerous to humans, there are a few red spider species in Wisconsin that do pose a potential bite risk.

Red Widow Spider

The red widow spider (Latrodectus bishopi) is a highly venomous species found in certain regions of Wisconsin as well as other parts of the central and southern United States. Identified by its glossy black abdomen with red hourglass marking, this spider is a relative of the more notorious western black widow.

Red widows inhabit sheds, barns, woodpiles, and other undisturbed outdoor areas. They build messy cobwebs and are not aggressive unless provoked. Still, they will bite in self-defense if trapped against bare skin.

Though rare, red widow bites can cause muscle aches, nausea, and paralysis of the diaphragm in some cases. However, most bites have mild reactions without serious complications.

Northern Black Widow Spider

The northern black widow (Latrodectus variolus) can also be found in Wisconsin as well as much of the northeastern United States and parts of Canada. As the name suggests, this spider has jet black coloring and the signature red hourglass shape on its underside.

Northern black widows construct webs in undisturbed, sheltered spots like woodpiles, sheds, and culverts. Bites most often happen when humans come into direct contact with the spider while cleaning or working outdoors.

This widow's venom is highly toxic and can cause severe muscle cramping, nausea, and difficulty breathing in rare cases. Seek medical attention if bitten.

Brown Recluse Spider

While not truly red, the brown recluse spider can have a reddish hue on parts of its body. This notoriously venomous species (Loxosceles reclusa) makes its home in southern Wisconsin.

Brown recluses inhabit sheds, garages, woodpiles, and other secluded, dry spots. They have six equal-sized eyes arranged in pairs rather than the usual eight. Bites often occur when spiders get trapped against bare skin.

The brown recluse has cytotoxic venom that can break down skin tissue and cause ulcerative lesions. Though rare, severe reactions can involve organ damage in extreme cases.

Redback Spider

Native to Australia but inadvertently introduced in some areas, the redback spider (Latrodectus hasseltii) has been reported sporadically in Wisconsin over the last few decades. It likely hitches rides on imports from the Southern Hemisphere.

Distinguished by a prominent red stripe on its abdomen, the female redback spider is venomous and capable of inflicting serious bites. Outdoor sheds, woodpiles, and debris provide prime habitat for this spider.

Redback venom can cause severe muscular pain, sweating, vomiting, and headache. Antivenom is available in Australia to treat serious cases.

Hobo Spider

The hobo spider (Eratigena agrestis) earns its common name from its tendency to wander into homes and vehicles. Native to Europe, it has become established in parts of the northwestern and northeastern United States.

Hobo spiders have a herringbone pattern on their abdomens and 3 rows of 4 eyes each. They build messy webs in dark places like basements, sheds, and woodpiles. Bites typically occur when spiders get trapped against bare skin.

Though hotly debated, some research suggests the hobo spider has venom capable of causing minor skin injuries in humans. Still, serious reactions seem very uncommon.

Identifying Red Spiders in Wisconsin

Many red spiders in Wisconsin are not dangerous to humans. Certain identification features can help distinguish harmless species from potentially dangerous ones like widows and recluses.

Number of Eyes

Most spiders have 8 eyes, but some dangerous ones have fewer. Brown recluses have 6 equal-sized eyes in pairs. Red widows have 8 eyes arranged in 2 rows of 4.

Violin Markings

Look for violin-shaped markings on the spider's cephalothorax (fused head and thorax). These are signature patterns of recluse spiders like the brown recluse.

Leg Length

Recluse spiders have shorter, more compact legs relative to their body size compared to most other spiders. Their legs may also be lighter in color.

Web Type

Dangerous spiders like widows and recluses tend to build messy, irregular webs in undisturbed areas. Funnel weavers and orb weavers make more organized web patterns and are not harmful.

Body Shape

Many dangerous spiders have more compact, oval-shaped bodies. Harmless grass spiders are recognized by their elongated, spindly bodies and faint patterns.

Preventing Bites From Red Spiders in Wisconsin

While the risk of being bitten by a venomous red spider in Wisconsin is low, there are some sensible precautions you can take to further minimize chances:

Reduce Clutter

Get rid of debris piles, rock stacks, and other clutter around the home where spiders could hide. Tidiness discourages their presence.

Seal Cracks

Seal any cracks or crevices where spiders could sneak into your home. Use caulk and weatherstripping to close gaps around windows and doors.

Ventilate Areas

Improve ventilation and reduce dampness in basements, sheds, garages, and other common spider havens. Let the sun shine in when possible.

Manage Lighting

Install bright lighting in dark, infrequently accessed areas. Dark spaces attract spiders, while illumination repels them.

Check Before Reaching

Inspect dark corners, under furniture, and inside containers before blindly reaching to avoid startling hidden spiders.

Use Gloves Outdoors

Wear heavy gloves when cleaning debris or moving stored items outside. Bites often happen when spiders get pinched against bare hands.

Shake Out Items

When bringing items indoors that have been stored in sheds or garages, give them a good shake or cleaning to dislodge any clinging spiders.

What to Do if Bitten by a Red Spider in Wisconsin

While severe reactions are uncommon, seek prompt medical care if bitten by a suspected widow or recluse spider in Wisconsin. In the meantime:

Wash the Wound

Gently clean the bite area with soap and water to help reduce risk of infection. Do not scrub harshly.

Apply Ice

Wrap ice cubes or a cold pack in a towel and apply to the bite to help reduce swelling and pain.

Elevate the Area

Position the bitten limb higher than the heart if possible to slow venom absorption. Keep movements minimal.

Avoid Home Remedies

Do not attempt to cut open the wound or apply suction. Avoid using homemade treatments like electrical shocks as these can harm more than help.

Take Photos

If possible, take photos of any spiders or distinctive bites to help with medical identification.

Monitor Symptoms

Observe for signs of severe reaction like intense pain, nausea, difficulty breathing, or uncontrollable muscle spasms. Seek emergency care promptly if these develop.

While human fatalities are extremely rare, red spider bites can in worst cases cause severe reactions. Stay vigilant when cleaning undisturbed areas and call 911 regarding any concerning bite symptoms.

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.