Spiders in Illinois: How to Identify Those you Encounter

Wherever we go in Illinois, we are always just a few feet from one of the 500 known species of spiders in Illinois.

Since we will encounter these spiders indoors or outdoors, this article breaks the content into those two locations.

Please note, however, only some are commonly found indoors, and others frequent the external parts of our homes, where they sporadically wander in.

Spiders in Illinois you’ll find outdoors.

orb weaver spiders in Illinois
Labyrinthine Orb Weaver Spider on Kennesaw Mountain

Orb weaver spiders in Illinois.

Orb weaver spiders in Illinois and Common house spiders are directly responsible for many of the Halloween decorations sold yearly. The webs of these two spiders, woven from radial strands and fashioned into spoke wheel-shaped nets as large as three feet in diameter, have become iconic symbols of fear used in thousands of scary movies and book covers.

Orb weaver spiders in Illinois: Description.

Orb weaver spiders in Illinois come in many sizes and colors, but most are brightly hued and have conspicuously hairy or spiked legs. Orb weavers also have enormous abdomens that overlap (as seen in the photo above) the rear end of their cephalothorax.

The abdomens of orb weaver spiders also vary in texture (smooth or spiny), but most are irregularly shaped.

The color of an orb weaver spider indicates when it will be most active. Brighter-colored orb weavers hunt during the day. Earth-colored (brown and gray) orb weavers hunt primarily at night.

spiny backed orb weaver spiders in Illinois
Spiny-backed orb weaver spider (Gasteracantha cancriformis) macro – Pembroke Pines, Florida, U.S.A. Shutterstock.com/Sunshower Shots

Spiny-backed Orbweaver spiders in Illinois: Identification.

Female Spiny-backed Orb weavers in Illinois can range between .20 and nearly .35 inches in length and are 1/2 inch wide with six-pointed abdominal projections often referred to as “spines.”

The carapace, legs, and venter are predominantly black, marked with white spots on the underside of the abdomen. Additionally, typical specimens have a white dorsum covered by black spots and red spines.

Spiny-backed orb weavers in Illinois from various locales may vary in the hue of their abdominal dorsum, from yellow to white; spines can range from black instead of red and even be nearly entirely black on both ventral and dorsal sides.

In comparison to females, males are much smaller – at only 1/10th inch long with a slighter longer than wide frame – varying slightly in color as well with gray abdomens plus white spots replacing large spines and several small humps taking up residence posteriorly.

Spiny-backed orb weavers ranging from southern California to Florida, the spiny-backed orb weaver has been spotted around various parts of the United States as well as other countries across the world. These spiders usually make their homes on trees and shrubs near houses or nurseries in residential areas.

furrow orb weaver spiders in Illinois
Larinioides cornutus, Furrow orb weaver spider. Photo credit: Shutterstock.com/ASkoulis

Furrow orb weaver spiders in Illinois.

The Furrow orb weaver spiders in Illinois might be scary, even if you do not have arachnophobia. It does look mean and dangerous, but it is neither. As more and more mosquito-borne diseases spread into the human population, the Furrow orb weaver could become an important asset. Having a few around the exterior of your home may even be your last line of defense.

As a result of the importance of the Furrow orb spider and its harmlessness to humans and most pets, I urge you to leave them alone. Indeed, I certainly will not explain how to kill or remove them.

Furrow orb weaver spider in Illinois: Description.

There are three species of furrow orb weaver spider in the United States. Larinioides corntus (Furrow orb weaver), Larinioides patagiatus (Dusty orb weaver), and Larinioides sericatus (Gray cross spider).

Furrow orb weaver spiders come with gray, red, olive, gray, or tan abdomens with inky, edged zigzag markings running down their lengths. These markings resemble a furrow or edges of a wavy leaf. The front two legs are longer than the rear legs, but all the legs are banded and have small spines.

Furrow web spiders can grow to have a body length of about 1/2 inch, not including the leg span.

Furrow orb weavers have exoskeletons that are dark brown, gray, or reddish and overspread with extremely fine hairs. Unlike other orb weavers, their abdomens are not dull looking but smooth and polished. 

Unlike most other spiders, furrow orb weaver males are nearly the same size as females and have the same markings. As a result, furrow orb weavers can survive most winters and are often seen waiting in the middle of their webs.

spotted orb weaver spider in Illinois
Close-up photo of bristly and corpulent orange and attractive, Spotted Orb Weaver spider (Neoscona crucifera) plying its trade by sucking on its most recent victim in its web. Photo credit: Shuitterstock.com/HM Thompson

Spotted orb weaver spiders in Illinois.

The Spotted orb weaver (Neoscona crucifera) is a captivating arachnid in the Araneidae family, found from Maine to Florida on the East Coast and Minnesota in Midwest America, reaching down to Arizona and southern California.

This orb-weaver spider also has two common names: Hentz orb weaver or barn spider – although this latter name can sometimes be misused for another type of creature called Araneus cavaticus.

Spotted orb weaver: Description.

Typically active at night, female Spotted orb weaver spiders in Iowa may switch to a daily schedule in the fall. Females range between 0.35–0.75 inches long, while males are smaller in size.

The top of their abdomens is brown and hairy with alternating light and dark brown stripes on their legs; meanwhile, the underside displays two white spots against a black background.

The Spotted orb weaver in Iowa boasts a wide array of colors and patterns but most typically displays rusty red or golden orange. Their webs are incredibly giant in circumference, often erected on artificial structures like buildings several feet above the ground level, particularly around outdoor lights.

Shamrock orb weaver spiders in Illinois
A shamrock spider is munching on a fly. Photo credit: SHutterstock.com/Cathy Keifer

Shamrock orb weaver in Illinois: Identification.

The Shamrock orb weaver spider in Illinois is easily recognizable due to its striking features, such as a beige or brown body with a high contrast of luminous green, yellowish-brown, or orange abdomen.

Additionally, this species boasts distinct black legs and white dots adorn the back – all qualities that help discern it from other types of orb-weavers.

Furthermore, Shamrock orb weavers have large round abdomens, which may also vary in coloration, usually displaying shades of beige and brown but sometimes adding hints of green for an extra pop!

Female Shamrock orb weaver spiders are 0.9 inches, and males are typically smaller.

To the untrained eye, Araneus trifolium is often mistaken for its orange cousin–the pumpkin spider or Araneus marmoreus. However, distinguishing this shamrock spider from other orb weavers is not a difficult task. To identify it quickly and easily, look for several white dots adorning its back and brown or beige legs with white bands around its joints.

Native to both the United States and Canada, the shamrock orb weaver spider is a part of the Aaneidae family.

As these arachnids prefer moist environments, they are usually found in humid areas where their webs can capture droplets of moisture for them to drink.

It’s common for Shamrock orb weavers in Iowa with an orange abdomen to be mistaken as marbled orb weavers (Araneus marmoreus).

Marbled orb weaver spider in Illinois
Marbled orb weaver. Photo credit: Shutterstock/Alex Conan.

Marbled orb weaver Spiders in Illinois: Description.

Marbled orb weaver spiders in Illinois are part of the genus Araneus which, with nearly 1,500 species worldwide, makes it the largest spider genus. 

Author’s note: Before the internet, I visited the town library weekly to look things up. I always believed Marbled orb spiders were in the Thomisidae family (due to the oversized back reaching over the cephalothorax. And I apologize for the spiders that escaped my glass jars in that library. 

Adult female Marbled orb weavers, like the one pictured above, can get as large as .8 inches in body length. Marbled orb weavers have orange heads and orangish red bands on their legs. Their huge abdomens are yellow with black or dark purpled marbled markings.

Male marbled orb weavers are 1/2 the size of the females.

Marbled orb weaver spider in Illinois: Habitat.

The marbled orb weaver is found from Texas to North Dakota and the east to the Atlantic States. In addition, it is found throughout Alaska and Canada.

Marbled orb weavers live near water sources like ponds, rivers, streams, and creeks and make their webs in the wooded areas and vegetation (tall grasses, brush, shrubs, cattails, and reeds) nearby.

Marbled orb weaver spider: Webs

Marbled orb weaver spider webs run vertically and have a single alert thread the spider uses as a trip wire. This trip wire allows the marbled orb weaver to remain hidden in its silken retreat off to the side of the web (and away from the view of potential predators). 

The web of a marbled orb spider in Illinois is exceptionally sticky. Any insect landing in it will be unable to remove itself with a, and maybe despite, any considerable struggles. These struggles are signaled by vibrations to the waiting marbled orb weaver nearby, and it quickly runs out and captures its victim.

What makes the web of a marbled orb weaver such a terrible thing to get entangled in is the tiny droplets of glycoproteins that dot each silken thread. These droplets are so sticky an insect cannot remove itself or even a single leg, limb, or wing once it has made contact with them.

Crab spiders in Illinois.

Bursting with color and vibrancy, Crab Spiders don’t sit in webs waiting for prey but actively ambush any insects that land near them. These captivating arachnids settle on flowers to camouflage themselves among the petals, which helps them avoid their predators. But an often unexpected location you may find a Crab Spider is indoors! The Running species of these spiders (Philodromidae) can search more openly for its victims – so if you ever see one strolling across your living room wall or ceiling, it’s sure been roaming around outside first!

Crab spiders are aptly named due to their crab-like movements and the unique leg formation of two extended front pairs and shorter back legs. These tiny arachnids typically measure ¼ inch long, though you may not even notice them skittering around your home as they often enter on flowers or plants from outside. So rest assured; potential encounters will not include a bite from these benign creatures!

Crab spiders in Illinois
Goldenrod Crab Spider

Crab spider identification.

Crab spiders come in many colors, including pink, yellow, blue, black, white, and green. The easiest way to identify a crab spoiler is by noting the front four legs that are longer and thicker than the four rear legs. 

The crab spider has eight eyes mounted on a lump on the front of their cephalothorax. They have two forward-mounted claws, flat bodies, and crabwise legs.

The crab spider can change color slightly with each molt, allowing it to camouflage itself against its current background. Some researchers believe crab spiders can even assume the colorations of their prey.

Crab spiders do not make a web, instead using a single start of silk to support themselves. Females wait for prey while sitting patiently on a plant or flower. Male crab spiders hunt while wandering around.

Special crab spider types.

In the Thomisidae family, there are 2100 species and around 175 genera.

The Goldenrod spider is of the genus Misumena, Misumena vatia in particular. They are one of the species of crab spiders known to change color from their normal or resting color to meet their predatory needs.

Bark crab spiders (Bassaniana) live camouflaged amongst the bark of trees while hunting prey.

Oxytate, which turns green to conceal itself in the grass or on a leaf.

Phrynarachne spiders that look like bird poop.

What do Crab spiders eat?

The venom of a crab spider is powerfully toxic and allows these spiders to take down much larger prey (seen in the photo above and below). 

Crab spiders eat mostly anything that comes within range. So grasshoppers, butterflies, wasps, bees, aphids, caterpillars, flies, beetles, and other insects are fair game to these potent killers.

And if prey is scarce, many crab spiders can live off the nectar and pollen from the flowers they hunt and mimic.

Garden spiders in Illinois.

Imagine the eerie webs of spiders on a foggy Halloween night or in a mysterious haunted house. Yet you’d be surprised to know that many orb weavers are often found outdoors!

These web-spinning arachnids attach their large silky webs to tall vegetation, porches, and other structures where they patiently wait for insects stuck in them – quick as lightning, these spiders move at full speed to wrap up the prey with silk. So come fall season, expect massive egg sacs from these eight-legged critters too!

Orb weavers are an incredibly diverse and visually striking species with some of the most colorful members, including Argiope spp. Garden spiders can reach up to an inch in length, and Micrathena spp., Gasteracantha spp.

Spiny-backed spiders are found in forests or gardens with brightly colored spike-like projections on their abdomens. Though rarely experienced, a bite from these orb weaver spiders is similar to that of a bee sting!

Garden ghost spiders in Illinois
” Hibana gracilis,” the garden ghost spider, is a species of ghost spider in the family Anyphaenidae. It is found in the United States and Canada. Photo credit: Shutterstock.com/Soflo Shots

Native to the United States and Canada, the Garden Ghost spider, “Hibana gracilis,” commonly known as the garden ghost spider, is a ghost spider belonging to the Anyphaenidae family.

Garden Ghost Spider: Identification.

Garden Ghost Spiders boast an unmistakable appearance, boasting an oblong and pointed abdomen and a creamy-white body further accented by a pale brownish triangular abdominal stripe. Moreover, when viewed up close, the spiders reveal black spines on their eight long legs and two extended pedipalps resembling black boxing gloves – all of which render Garden Ghosts incredibly identifiable.

The small yellowish-white or pale brown-white spiders typically measure 0.15″ – 0.3″ long. Another identifiable feature of Garden ghost spiders in the family Anyphaenidaeis that the two central eyes on the bottom row are the smallest.

Easily identifiable, the whitish Garden ghost spider has a distinctly pointed abdomen and pale tan legs with black spines. Additionally, this arachnid species features two rows of four eyes for maximum visibility.

Golden silk spiders in Illinois
Golden silk spider. Photo credit: Shutterstock.com/John Dorton

Golden silk spiders in Illinois.

Golden silk spiders (Trichonephila clavipes) in temperate North America only live for one year before the females produce an egg sac in late fall. The egg sac will wait out the winter and produce spiderlings as the temperature increases in the spring.

One of the more interesting facts about Golden silk spiders in Illinois is their use in the South Pacific.

Inhabitants of the South Pacific take advantage of Trichonephila maculata females as a source of protein. Not only do they build webs on bamboo frames to be used as fish nets, but they also relish eating them either raw or roasted!

Different sources have described the taste as a mixture between raw potato and lettuce, while others say it tastes nutty with a consistency similar to peanut butter.

Golden silk spiders: Identification.

In North America, females of the Golden silk spider species are amongst the largest non-tarantula spiders and possibly even the biggest orb-weavers in our country. They were only rivaled in size by Argiope aurantia (Fabricius) or perhaps larger Araneus species such as Araneus bicentenarius.

Female Golden silk spiders in Illinois tend to be quite noticeable, boasting an impressive size of 1-1.5 inches in length and exhibiting characteristic traits such as a silvery carapace, yellow spots on their dull orange or tan cylindrical body, brown and orange banded legs and hair brushes (gaiters) located on tibial segments I, II, IV – all which make them easily recognizable.

As for the male Golden silk spider population, they fall short of this by being rather inconspicuous dark brown, slender creatures averaging .25 inches in length that could go completely unnoticed if not found within the webbing of females.

Jumping spiders in Illinois
Jumping spider. Photo credit: Shutterstock.com/Hendra Syafie

Jumping spiders in Illinois.

If you have to have spiders in your house, have jumping spiders. The venom from jumping spiders is harmless to humans, and the darn things look cute.

Jumping spiders are truly fascinating arachnids. They don’t wait in their web for a meal; they hunt it down. The male jumping spider woos his potential mate with song and dance. And jumping spiders have excellent vision.

Oh, and jumping spiders can jump. Boy, can they jump!

So, If you just found a jumping spider in your house, wait for a second and read all about it. Then, hopefully, you’ll let it live.

Jumping spiders in Illinois: Description.

Jumping spiders in Illinois are spiders in the family Salticidae, consisting of over 6,000 species and making it the most prominent family of spiders. Jumping spiders are well known for their ability to jump long distances and for the excellent vision provided by their two large anterior median eyes.

Jumping spiders range from 1/25” to 1” in length. There is no limit to their body colors or patterns. However, male jumping spiders are more colorful than the more often dull-colored females.

And, of course, there are the eyes of the jumping spider. It has four pairs of eyes, two of which (the anterior median eyes) are almost comically large and sit next to each other on the spider’s flat face

Cute, right? Indeed, they are cute enough to keep as pets.

Related: How long do ants live?

Related: What do ants eat?

How jumping spiders hunt their prey.

Jumping spiders hunt like humans. Some salticid species hunt their prey like human archers hunt deer by taking a high, seated position and then stalking any prey they observe. 

Other jumping spiders use the spider version of the “still hunting.” Still hunting is used by bear hunters who continually move, stop, scan, and move again. 

Jumping spiders prefer to ambush their prey instead of running after them and chasing them down. To do this, jumping spiders are willing to take the less traveled road. They will take meandering routes climbing trees and branches and circling behind the vegetation, even to the point where they lose visual contact with their target.

bold jumping spiders in Illinois
Bold jumping spider. Photo credit: Shutterstock.com/Safwan Rozi

Bold Jumping spiders in Illinois.

Bold Jumping spiders (Phidippus audax) are a member of the genus Phidippus. Notable features include their big eyes and iridescent chelicerae. All jumping spiders employ stereoscopic vision for hunting prey and communicating with potential partners during mating rituals.

Native to North America yet found in Hawaii, the Nicobar Islands, the Azores, and The Netherlands; these black arachnids are identifiable by the white triangle on their abdomen.

Bold jumping spider: Description.

Bold jumping spiders in Illinois are unmistakable creatures – females reach up to .6 inches in body length, whereas the males strand an oval abdomen, making them easy to spot!

The Bold jumping can easily be identified by its white triangular mark in the center of its back, accompanied by two more minor spots beneath it. Its upper abdomen is also marked with a distinct lateral white band that distinguishes this species.

However, what stands out most about these creatures are their tremendous and powerful legs: males have distinctive fringes on their legs and pedipalp, while females boast a longer fourth pair of legs than those found on male specimens.

The chelicerae of adult males glisten emerald green and boast spectacular markings and tufts of fur over the eyes, whereas spiderlings’ chelicerae display orange hues that gradually lighten with age. Furthermore, Bold jumping spiders in Illinois come in various sizes and colors depending on their habitat location.

Bold jumping spider: Vision.

The bold jumping spider in Illinois is a type of arachnid with superior eyesight compared to other spiders. This exceptional visual system aids in mating, hunting, and even learning behaviors, as the four pairs of eyes arranged around its head grant it nearly 360° vision. This remarkable adaptation allows jumping to take in their entire environment easily!

While spiders have eight eyes, the two most prominent ones – principal or anterior median (AM) eyes- are positioned on the front of their head. These AM eyes possess retinas that can rotate to follow a moving object and provide extraordinary resolution with the added benefit of color perception. The three secondary pairs of the spider’s eye, which scientists name anterior lateral (A.L.), come after them in importance and size.

The anterior median (AM) eyes are designed to detect incoming objects and situations. Similarly, the posterior median (PM) and posterior laterals work together to sense movement from both sides and behind them.

tan jumping spiders in Illinois
Tan jumping spider. Photo credit: Shuitterstock.com/Gmgadani

Tan jumping spiders in Illinois.

The Tan jumping spider in Illinois is a relatively small, furry arachnid with a most peculiar feature – two massive front-facing eyes giving them a more mammalian look.

All eight of their eyes form an almost uninterrupted circle along their heads, providing near 360-degree vision, and their brownish body coloration helps to camouflage the environment.

Tan jumping Spider in Illinois: Description.

Like other jumping spiders, the Tan Jumping spider (Platycryptus undatus) is covered in fur and has two forward-facing goggle-like eyes that give it remarkable vision. It moves in a peculiarly jerky gait while also being gifted with extraordinary jumping abilities.

Its spinning of silk includes creating a single tether line for additional security when exploring or traversing long distances and making cocoons to protect itself and its eggs from harm.

Females measure up to ⅝ inch in length (not including legs), while male counterparts typically reach no more than ⅜ inch.

The tan jumping spider in Illinois is highly skilled at blending into its environment, featuring grays, tans, and browns that often contain flecks of black and white plus — in some cases — a reddish hue. Its look can range from zebra-like stripes to an even, gray pattern across its body; the abdomen also typically features undulating shapes for extra camouflage.

In addition, these spiders’ bodies are unusually flattened, which further aids in their concealment when necessitated.

The tan jumping spider’s pedipalps, those finger-shaped appendages close to the face, are usually encased in fuzz and pure white. Males have chelicerae (fangs that the pedipalps may conceal) that boast long, white hairs, while female chelicerae appear black and glistening with no hair present.

Zebra jumping spiders in Illinois
Zebra spider. Photo credit: Nigel Hoult. https://creativecommons.org/licenses/by/2.0/

Zebra jumping spiders in Illinois.

Zebra spiders are like all other jumping spiders; If you have to have spiders in your house, have jumping spiders. The venom from Zebra jumping spiders is harmless to humans, and the darn things look cute.

Zebra jumping spiders in Illinois are truly fascinating arachnids. They don’t wait in their web for a meal; they hunt it down. The male zebra spider woos his potential mate with song and dance. And jumping spiders have excellent vision.

Zebra spiders in Illinois: Description.

Female Zebra spiders (Salticus scenicus) range in size from .2 to .35 inches; males are smaller, with the largest being about .25 inches. The males, who often struggle with the female and other suitors, have larger jaws than the females.

And, of course, there are the eyes of the Zebra spider. It has four pairs of eyes, two of which (the anterior median eyes) are almost comically large and sit next to each other on the spider’s flat face. The larger eyes give the Zebra jumping sider binocular vision.

Zebra spiders are known for their black hairs with white hairs that form zebra-like stripes.

Zebra spiders in Illinois: Habitat.

Zebra are found across Europe, North America, and North Asia.

Outdoors are found in open habitats such as the faces of rocks, rocky beaches, and trunks of trees.

Zebra jumping spiders in Illinois do not create webs to catch their prey. Instead, jumping spiders build “retreats.” Retreats are more loosely woven and serve only to protect the spider and house the female and her eggs.

You will find Zebra jumping spider retreats inside your home under chairs and tables, near windows and doors, or tucked between cracks in wood flooring. Outside, Zebra jumping spiders in Illinois build their retreats on leaves, tight spaces in wood piles, and crevices in tree bark.

Jumping spiders have poor night vision and spend the night in their retreats. During the day, they are attracted to sunlit areas inside your home (windows are a favorite as other insects will be drawn to them). Outside, you’ll find jumping spiders running everywhere the sun has brightened (pool decks, fences, patio stones, etc.).

Aside from the odd, likely trapped against its will, window-dwelling Zerba jumping spider jumping spiders are not inclined to live inside your home. Indeed, you will never find you have an infestation of jumping spiders

black widow spiders in Illinois
Front close-up of a Brown Recluse spider. Photo credit:Shutterstock.com/Sari O’Neal.

Black widow spiders in Illinois.

Black widow spiders in Illinois are the easiest spider to identify. But, unfortunately, black widow spiders are also the most horrifying spider to identify up close and personal. The fear of the hourglass-shaped spider’s bite is world-renowned throughout the temperate regains of the entire world.

In many articles on black widow spiders in Illinois, the author suggests that the reports of their venom and the inherent dangers of encountering black widow spiders are deemed “over-rated.”

That’s not true. Indeed, the black widow spider is nasty and potentially fatal to young and elderly humans. Therefore, any helpful article will recommend they be avoided, and those who live where black widow spiders reside can identify and prevent them.

The black widow spider in North America can also be red (Latrodectus bishopi ) or brown (Latrodectus geometricus). Despite their color, female black widows have dark-colored and easily identified reddish hourglass markings on the central underside. Only the female has a bite hazardous to humans.

Black widow spiders in Illinois: Fascinating facts.

A study conducted in the 1950s found that 80% of black widow spider bites happened to men, most of whom were bit on the penis. Ouch! Why? 

As reported in IFLScience.com, “Most of the black widow bites that were reported happened in outhouses. 

“So black widow spiders enjoy dark, low-to-the-ground sort of places. They especially love to make their cobwebs between two objects,” she explained, adding that bugs and flies love the stink of outhouses and made their home in the privvy bowls.

“So putting your web there is excellent. So imagine this. It’s the 1950s. You’re a dude. You need to go number two. You make your way out to the outhouse. You sit down, and your junk hangs there.”

“And as it does, it hits the cobweb. And the usually non-aggressive black widow instinctually runs over and bites down on the new creature that has landed on its web.”

Since bathrooms began moving indoors, the problem (disproportionate targeting of men and penises) seems to have gone away. Their bites today are rarely fatal, with the majority resolving without treatment and others being treatable in hospitals. “

Need any more reasons to fear black widow spiders?

Related: How long do ants live?

Related: What do ants eat?

Brown recluse spiders in Illinois
Front close-up of a Brown Recluse spider. Photo credit:Shutterstock.com/Sari O’Neal.

Positively identifying brown recluse spiders in Illinois.

Identifying brown recluse spiders in Illinois begins by considering where you have found the spider in question.

Brown recluse spiders (Loxosceles reclusa) are commonly found in the Southern Central and Midwestern states. Sure, you could be looking at a traveler who has hitched a ride north, further east, or west. However, that spider is well outside its native territory. Indeed, it will never procreate enough to become an actual problem on the level of an infestation.

Traveling spiders (like the Hobo spider) sometimes enter and inhabit new regions. But the brown recluse spider won’t survive such migrations.

So, unless you have moved from western Kentucky to, let’s say, New York, you should be okay. However, there’s no sense in taking chances. Perhaps be careful when unpacking those boxes and chairs—just to be sure.

Brown recluse spiders: The eyes have it!

Adult brown recluse spiders in Illinois are about the size of an American quarter (nearly an inch). Surprisingly, they are brown or tannish in color. Their abdomens and legs have no bands, mottling, stripes, or visible spines.

Don’t forget that they neither play violins or fiddles nor possess images of such musical instruments in markings or tattoos.

What sets the brown recluse spider in Illinois apart from most other spiders you will encounter? First, they only have six eyes!

Retake a look at the close-up photo above. You’ll see that brown recluse spiders have a semi-circular eye arrangement (three sets of two), but most spiders have eight eyes. 

Okay, I’ll admit that counting the number of tiny eyes on an inch-long spider is difficult. And no one has a magnifying glass at home, which is readily available anymore. So grab that iPhone, snap a photo, and zoom in on the spider’s face.

When you get to the hospital, you can use the picture to help diagnose why you are shrieking in agony and convulsing on their table. Just kidding, we’ll talk more about the bite of brown recluse spiders later.

The slanting legs of the brown recluse spider in Illinois.

Brown recluse spiders are rather plain with uniformly tan or brown abdomens, but their legs (which lack spines, as noted above) are covered in fine hairs. In addition, these legs are slanted (hence the scientific name Loxosceles, meaning slanted legs in Latin).

Brown recluse soldiers in Illinois do not walk funny; instead, the rest with their legs slanted.

wolf spiders in Illinois
A female wolf spider carrying her spiderlings on her back. Photo credit: Shutterstock.com/Gabriela Bertolini.

Wolf spiders in Illinois.

The wolf spider in Illinois is a perfectly camouflaged, hairy, and wickedly fast pursuer of its prey. Just like the wolf it is named after. However, as scary as they look, the wolf spider does not pack as dangerous a bite as once believed.

Let’s take a close-up look at the wolf spider, learn how to identify it, and discover some interesting facts about how it manages to live just about everywhere in the world.

Wolf spider in Illinois: Description.

Currently, there are 128 genera and over 2,800 species of wolf spiders. Amongst all those species, the body size of individual wolf spiders ranges from 1/25 to 1.5 inches.

For the record: The largest wolf spider species is the Hogna ingens, the Deserta Grande wolf spider. The female of this critically endangered spider has a leg span of nearly 5 inches.

Perhaps the most distinguishing feature of the wolf spider is its face. This spider has three rows of eyes, four small ones on the bottom, two medium-sized ones on the top, and two much larger eyes in the middle. Wolf spiders are known to have excellent vision for spotting and tracking prey.

Wolf spider eyes have reflective tissue like canids such as wolves and coyotes. This tissue, tapetum lucidum ref, lects visible light back through the retina and increases the light available to the photoreceptors—significantly increasing the wolf spider’s night vision.

And just like wolves and coyotes, you can use a flashlight at night to locate wolf spiders by scanning an area and spotting the reflected “glow” from the light’s beam.

The wolf spider in Illinois has slightly inferior night vision to the jumping spider, which in turn is bested by the huntsman spider.

The wolf spider also has an impressive set of fangs.

Related: Tarantula bites.

Related: Tarantulas: Appearance, diet, and mating.

Are bites from wolf spiders dangerous?

Like the hobo spider, the wolf spider was thought to have had a dangerous bite for many years. However, the venom of a wolf spider is not a serious medical problem for most people. Indeed, these spiders have bites that produce only slight redness and swelling.

However, the lack of a venomous bite should not lead you to believe they are safe to pick up or mishandle.

Now, if you are reading this because a brown spider in Illinois bit you, I have one caution. While a simple wash and treat with first aid might be all you need for a wolf spider bite, that does not mean it was the spider that bit you.

If you cannot positively identify that the bite came from a wolf spider, recover the (dead) spider and consult with a doctor. The doctor can use the dead spider (please don’t use enough for killing for the corpse to be classified as “remains unviewable”) to identify the spider for you.

Why speak with a doctor and bring the dead spider? A giant brown recluse spider looks a hell of a lot like a brown wolf spider. If you are bitten brown a recluse spider, you should get prompt medical treatment.

So, unsure which spider bit you? Then if it can be easily captured or killed, place it in a clear, tightly closed container so it may be identified—and get thee to a physician.

Related: How long do ants live?

Related: What do ants eat?

Spiders in Illinois that can live indoors.

cellar spiders in Illinois
Pholcid spider, a spider with very long legs, Daddy long-legs. Photo credit: Shutterstock.com/Matauw.

Cellar spiders in Illinois: Identification.

Cellar spiders in Illinois range from less than a 1/10th of an inch to 2/5ths in length. They have peanut-shaped bodies and oversized leg lengths, with some cellar spiders having long spans of nearly two inches.

The length of their legs is one key identifier; most cellar spiders have legs four times as big as their bodies. The other identifier is the body width being three times as wide as the long.

They have eight eyes (grouped as two laterals of three and two smaller eyes whose borders touch each other. Cellar spiders have bodies that are colored gray, pale yellow, and brown and sometimes even appear as clear —with chevron marking.

Cellar spiders are found in every country and continent except Antarctica. 

Related: How to identify the Brazilian wandering spider.

Cellar spider webs.

Cellar spiders make unsophisticated and unusual webs for a spider. 

Like black widow spiders, they wait for their prey while hanging upside down. When prey is detected, cellar spiders vibrate their webs with their bodies, and this helps further entangle any insects caught in it. 

When cellar spider bite, they inject a toxic venom (though it cannot harm a human) that is legendarily thought to be the most potent venom in the spider kingdom. This legend has yet to be scientifically proven.

Cellar spiders in Illinois do not repair, clean, or remake their webs. Instead, they build additional layers on existing webs. This habit may save them time and energy, but in your home or barn, it quickly makes the web of a cellar spider conspicuous.

Related: How to identify huntsman spiders.

Cellar spider
Marble cellar Spider with younglings. Photo credit: Shutterstock.com/Raavanan.

Cellar spider reproduction.

An inseminated female cellar spider in Illinois will produce an egg sac with between 12 and 60 eggs. She will then carry this sac in her mouth until the spiderlings emerge.

These young spiders will travel on their mother’s back and only be considered mature after their fifth molt—at approximately one year of age.

After reaching adulthood, cellar spiders have a life span of about two years.

Related: How long do ants live?

Related: What do ants eat?

Further recommended reading about spiders.

Spider pages: Learn how to identify and avoid these spiders.

Can house spiders hurt you? Are house spiders Venomous?

Do Spiders Sleep? Do They Dream like Humans?

Tiger wolf spider.

Cross orb-weaver spider.

Hump-backed orb weaver.

Triangulate cobweb spider.

Carolina wolf spiders.

Striped fishing spiders.

White-Jawed jumping spiders.

Black lace-weaver spiders.

Black Spiders: How to identify them.

Long-Palped ant-mimic sac spider.

Peppered jumping spiders.

Spotted ground swift spider.

Spinybacked orb weavers.

Parson spiders.

White spiders.

Striped spider in the U.S.

How long do spiders live?

Spider anatomy 101.

The most venomous spiders in the world.

Zebra spiders.

Furrow orb weaver spider.

Marbled orb weaver spiders.

Red house spider identification.

Purse web spider.

Crab spider: How to identify.

Orb weaver Spiders: How to identify and get rid of them.

Common house spiders: How to Identify and get rid of them.

Dark fishing spiders.

Six-Eyed Sand Spider: Is the White Sand Spider Dangerous?

10 biggest spiders in the world.

The Red widow spider

Giant Huntsman Spider: How to Identify the Largest Spider

Brazilian salmon pink bird-eating tarantula

Brazilian Giant Tawny Red Tarantula

Colombian Giant Redleg Tarantula

Cerbalus Aravaensis: Middle East’s Largest Spider

Camel spiders: Myths and Facts.

Net-casting spiders: How to identify these spiders.

White-tailed spider: How to identify and manage.

Katipo Spider: How to identify New Zealand’s venomous spider

Brown widow spider: How to identify and avoid the false widow.

Redback spiders how to identify them and prevent bites

Funnel weaver spiders vs funnel-web

Cellar spiders how to identify and get rid of them

How to identify the wolf spider

How to identify the hobo spider

Brazilian wandering spider how to identify and avoid

Huntsman spider how to identify the eight legged freak

Jumping spiders how to identify these harmless hunters

Black widow spiders how to identify and avoid

Tarantulas appearance diet and mating

Do tarantulas bite?

Brown recluse spiders how to identify and avoid

Dennis V. Gilmore Jr.

Dennis V. Gilmore Jr. is a former Marine Sergeant and the author of several books, including two on night hunting coyotes and red and gray fox. He has written several hundred articles on predator hunting for ThePredatorHunter.com.

Recent Posts