A Guide to Common Illinois Spiders
Illinois is home to thousands of spider species that range from harmless garden helpers to a few of medical concern. While the majority pose no danger, being able to identify venomous spiders can give peace of mind.
Benefits of Spiders
Before delving into venom risks, it's important to note that spiders play crucial ecological roles. As primary predators of insects, spiders control pest populations and prevent diseases from spreading.
Funnel weavers, orb weavers, crab spiders and more thrive outdoors in Illinois, catching nuisance bugs. Only a small subset of spiders have medically significant venom that can harm people or pets.
Illinois Spiders That Bite
Out of over 650 types of spiders found statewide, these warrant caution for their powerful bites on humans:
1. Brown Recluse Spider
Also called violin or fiddleback spiders for markings on the cephalothorax (body section), brown recluses have six equal-sized eyes and range from 1434 inches long. Their bites can destroy skin tissue and require medical care.
Identifying Features
- Light to medium brown color
- Dark violin-shaped marking on body
- Long, thin legs
- Three pairs of eyes instead of four
Habits
Brown recluses build irregular webs and dwell in dark, secluded places like attics, garages and woodpiles. Their range covers the southern half of Illinois.
Bite Symptoms
Initial redness and stinging transitions to severe blistering, tissue death and sloughing within days if untreated. Fever, rash, nausea and tiredness may also occur.
2. Northern Black Widow
This widowed spider has a shiny black torso with two reddish triangles on the underside along with long black legs. The venomous bite of female widows can be quite dangerous but rarely deadly in Illinois.
Identifying Features
- Black body with red hourglass marking underneath
- Spiky round abdomen
- Long black legs
- Females larger than males
Habits
Black widows build messy, tough webs usually close to the ground in woodpiles, sheds, rodent burrows and more across Illinois. Peak activity is at night to catch prey.
Bite Symptoms
Within minutes pain spreads from the bite site causing rigid abdominal muscles, nausea, profuse sweating, difficulty breathing and elevated blood pressure requiring medical assistance.
3. Yellow Sac Spider
This pale yellow spider with darker markings on its elongated abdomen can deliver toxic and painful bites. Yellow sacs measure up to 0.5 inches long and lurk around homes.
Identifying Features
- Pale yellow body
- Dark line running lengthwise on abdomen
- 8 eyes in two rows
- Chelicerae (mouth parts) longer than carapace
Habits
As the name implies, yellow sac spiders nest in tubular sacs attached to walls, furniture, autos and outdoor structures. They roam at night in search of small insects to eat.
Bite Symptoms
Bites cause initial burning followed by itching, redness, stinging and swelling, sometimes with more severe blistering, ulceration or skin sloughing in vulnerable people. Chills, fever, nausea or Headache may occur.
Other Venomous Illinois Spiders
While less common to find, a few other spiders have concerning bites as well:
Hobo Spider
A cousin of funnel web spiders with toxic venom that destroys soft tissue in some cases. Aggressive; found statewide.
Fishing Spider
Largest Illinois spider at over 2 inches big with semi-toxic venom. Resides near water statewide.
Wolf Spider
Fast-moving, hairy spider with mildly toxic venom causing redness/swelling if bitten. Seen often and statewide.
Treating Spider Bites
If bitten by one of the spiders above, take these steps for safety:
- Wash the bite area with soap and water
- Apply a cold compress to relieve swelling
- Capture/photograph the spider if possible
- Monitor for worsening symptoms
- Seek emergency care for serious reactions
While spider bites are uncommon, knowing how to ID and respond quickly makes all the difference.
Avoiding Spider Bites
Fortunately, some simple precautions greatly reduce run-ins with venomous spiders in Illinois:
- Seal cracks around windows/doors
- Clear clutter like piles of materials spiders nest in
- Inspect/shake out items before touching
- Wear gloves/long sleeves handling debris
- Install proper lighting outdoors
Common Harmless Illinois Spiders
While scary looking, popular spiders spotted around Illinois homes and gardens do not pose health threats, including:
1. Daddy Longlegs
Also called harvestmen, these spindle-legged spiders eat small insects and decaying matter. They cannot bite or spin webs despite myths.
2. Orb Weaver Spiders
From vibrant garden spiders to charlotte-making barn spiders, orb weavers use masterful web designs to catch flying insects but are harmless to people.
3. Jumping Spiders
As the name suggests, these charismatic spiders with big front eyes leap to catch prey instead of using webs. Completely safe despite speedy movements.
Understanding the risks versus benefits of Illinois spiders empowers smarter interactions. Learn what spiders call your area home and always use caution handling ones you can't identify!
FAQs
What is the most venomous spider in Illinois?
The northern black widow spider is considered the most venomous in the state. The brown recluse and yellow sac spiders also have concerning bites.
Where are brown recluse spiders found in Illinois?
Brown recluse spiders reside mainly in the southern half of Illinois in hidden spots like attics, piled materials and unfinished basements.
Do daddy long legs spiders bite?
No, daddy longlegs or harvestmen are harmless and do not have venom or mouths that can bite. This is a common myth about these spiders seen often in Illinois.
What should I do if bitten by a spider in Illinois?
Wash the bite area, apply ice, capture the spider if possible, monitor for symptoms worsening like nausea or blisters and seek medical attention for severe reactions.
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.
Add Comment