A Guide to Venomous Red Spiders Found in Iowa

Red Spiders Commonly Found in Iowa

Iowa is home to a variety of spider species, some of which have reddish coloration. While the majority of spiders in Iowa are harmless, there are a few venomous red spider species that reside in the state that residents should be aware of.

The Northern Black Widow Spider

One of the most infamous red spiders found in Iowa is the northern black widow (Latrodectus variolus). As their name suggests, female black widow spiders have a distinctive red hourglass marking on the underside of their abdomens. They weave messy cobwebs in undisturbed areas and prey on insects that become trapped in their webs. Female black widows have potent venom that can cause severe pain, muscle spasms, and nausea in humans, although deaths from black widow bites are rare.

The Brown Recluse Spider

The brown recluse spider (Loxosceles reclusa) is another venomous red spider that makes its home in Iowa. As the name suggests, this spider is brown in color but can sometimes exhibit a reddish hue. Brown recluse spiders have a violin-shaped marking on their cephalothorax (fused head and thorax). Bites from this spider can cause tissue damage, fever, chills, and muscle pain. However, despite their fearsome reputation, brown recluse bites are rarely fatal.

Jumping Spiders

Iowa is home to several species of jumping spiders that have reddish bodies. Some examples include the bold jumper (Phidippus audax), the regal jumper (Phidippus regius), and the bronze jumper (Eris militaris). These spiders get their name from their ability to leap several times their body size to ambush prey. Jumping spiders have excellent vision and are not aggressive towards humans.

Crab Spiders

Crab spiders comprise another group of spiders that sometimes exhibit red coloration. There are numerous crab spider species in Iowa, such as the elegant crab spider (Xysticus elegans), the spined micrathena (Micrathena gracilis), and the goldenrod crab spider (Misumena vatia). These spiders have a laterigrade (sideways) walking motion that resembles crabs. They do not spin webs but instead ambush prey. Crab spider bites generally only cause mild pain and swelling in humans.

Identifying Venomous Red Spiders

While the vast majority of spiders in Iowa are not dangerous to humans, accurately identifying venomous species like the northern black widow and brown recluse can help prevent serious bites. Here are some tips for distinguishing harmless red spiders from venomous ones in Iowa:

Web Types

Most venomous red spiders do not spin proper webs for catching prey. Black widows weave messy, three-dimensional cobwebs while brown recluses spin irregular webs in corners. If you see an organized, wheel-shaped web, it likely belongs to a harmless orb weaver.

Body Shape

Venomous red spiders like black widows tend to have more rounded, bulbous abdomens. Harmless jumping spiders and crab spiders have flatter, oval-shaped abdomens. If a red spider has a fat, rotund body, be wary.

Markings

The presence of distinctive body markings can help identify venomous species. Look for the red hourglass on black widows and the violin-shaped pattern on brown recluses. Most harmless jumping spiders and crab spiders lack these types of definitive markings.

Legs

Black widows and brown recluses have thicker, more uneven legs that appear almost furry. Harmless jumping spiders have smooth, slender legs adapted for jumping. If a red spider has very thick, fuzzy-looking legs, exercise caution.

Motion

Many venomous species move slowly and tentatively. If you see a red spider rapidly jumping or scurrying, it is likely non-dangerous. Be wary of spiders that move hesitantly and deliberately.

Avoiding Bites from Red Spiders

While venomous red spider bites are uncommon, you can take some simple precautions to avoid them around your Iowa home:

Reduce Clutter

Venomous spiders often hide in piles of unused debris and clutter outdoors and indoors. Get rid of unneeded items and tidy up any messy areas.

Wear Gloves and Long Sleeves

When cleaning garages, sheds, basements and other seldom-used areas of your home, wear gloves and long sleeves. This can prevent accidental bites.

Inspect Items Before Moving Them

Check underneath potted plants, furniture, boxes, and other items before grabbing or moving them. You don't want to get surprised by a hiding venomous spider!

Seal Cracks and Crevices

Sealing up cracks, holes, and crevices around your home's foundation can help keep spiders from sneaking inside. This is especially important for web-building species.

Use Caution in Wooded Areas

When hiking or playing in grassy, wooded areas, be cautious lifting logs, rocks, and other objects. This is where venomous spiders often lurk during the daytime.

What to Do if Bitten

Spider bites are exceedingly rare, even from venomous species like black widows and brown recluses. Regardless, here are some steps to take if you receive a spider bite in Iowa:

Wash the Bite Area

Gently wash the bite with soap and water to help reduce risk of infection. Do not try to scrub or suction out the venom.

Apply a Cold Compress

Applying a cold washcloth or wrapped ice pack can help ease swelling and pain at the bite site.

Elevate the Injured Area

If bitten on an arm or leg, keep the affected limb elevated while waiting for or traveling to medical care.

Take Over-The-Counter Pain Medication

Ibuprofen, acetaminophen, or other OTC pain relievers can help manage bite pain and discomfort.

See Your Doctor

Even if symptoms seem mild, it's wise to consult a doctor after any spider bite. Rarely, antivenom treatment may be recommended.

While the prospect of venomous red spiders in Iowa is scary, bites from species like black widows and brown recluses are unlikely. Being able to identify dangerous spiders, keeping your home tidy, and taking sensible precautions can let you rest easy!

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.