Did you know that there are hundreds of spider species in Illinois? The good news is that the majority are not harmful to humans and a bite may cause redness, swelling, and irritation.
Are you wondering what spider was in your home or the spider you saw in the yard? Continue reading to find out more about the most common spiders you may encounter in Illinois, from the most common to the least common.
1. Bold Jumping Spider
Female bold jumping spider
Scientific name: Phidippus audax.
Common name: daring jumping spider, bold jumping spider.
The bold jumping spider is a harmless spider that you will probably encounter in your home in Illinois.
The female can grow to 18mm in body length, with the male being smaller and growing to around 15mm in body length.
They are black with spots and stripes on their legs and abdomen.
They do not create webs to ensnare prey. Their webs are a safe place for them to retreat, store prey and eat their prey.
2. Spotted Orbweaver
Scientific name: Neoscona crucifera.
Common name: Hentz orbweaver, spotted orbweaver, barn spider.
Spotted orbweavers create orb-shaped webs that can be two feet in diameter. They hide in a curled leaf on the edge of their web during the day.
They vary from orange/red to yellow/brown with some being tan. Their markings can also vary with some having barely any pattern to others having a distinct zigzag pattern on the sides of their abdomens. The body and legs have bristles.
They are common in fields, gardens, backyards, parks, and woodlands.
3. Yellow Garden Spider
Yellow garden spider
Scientific name: Argiope aurantia.
Common name: yellow garden spider, black and yellow garden spider, golden garden spider, writing spider, zigzag spider, zipper spider, black and yellow argiope, corn spider, Steeler spider, McKinley spider.
Yellow garden spiders are also known and black and yellow garden spiders. They have distinct black and yellow markings on their abdomen with an almost white cephalothorax (the part of the body where the legs attach).
They can grow up to 1.10 inches (28mm) for females and 0.35 inches (9mm) in body length for males.
They will bite if they are harassed, but their bites are harmless and are often compared to a bee sting.
4. Grass Spiders
American grass spider
Scientific name: Genus Agelenopsis.
Common name: American grass spiders, grass spiders.
Grass spiders are common on summer nights in Illinois. These funnel-web weavers are known for the cave-like webs that they create on lawns, the spider hiding at the back.
They have large spinnerets on the top of the abdomen, giving the appearance of having a short tail.
They are exceptionally fast and drag passing prey into the funnel of their webs.
They are often confused as a wolf spider, with two black lines running down the side of a tan midline. The lines are not as thick as the wolf spider. The abdomen starts with dark lines but has a series of chevron markings.
5. Zebra Jumping Spider
Zebra jumping spider
Scientific name: Salticus scenicus.
Common name: zebra jumping spider.
The female zebra jumping spider can grow to 9mm with males growing to 6mm in body length.
They have black and white hairs which create stripes, giving this spider its name.
They are common in Illinois, often living near human homes. They are often seen on fences, walls, and plants, along with windowsills and behind curtains, hunting for their next meal.
6. Tan Jumping Spider
Female tan jumping spider
Scientific name: Platycryptus undatus.
Common name: tan jumping spider.
Tan jumping spiders are able to jump more than four times their body length when they ambush prey or escape predators.
They leap towards an insect while shooting out a strand of silk, which stops the prey from escaping. The spider does create a web, which is its shelter and a place to eat its meal at its leisure.
These small, tan, hairy spiders are friendly and do not have a reputation for biting unless they are handled roughly.
7. Orchard Orbweaver
Scientific name: Leucauge venusta.
Common name: orchard spider.
The orchard orbweaver is a long-jawed orbweaver that is found hanging upside down in the center of its orb-shaped web, which can span two feet in diameter.
They have green legs and sides, which can vary from light to dark green. They are silver with brown and black streaks on the top of the abdomen with yellow-orange or red spots close to the back of the abdomen.
8. Spined Micrathena
Adult female spined micrathena
Scientific name: Micrathena gracilis.
Common name: spined micrathena, castleback orbweaver.
The spined Micrathena female has pointed ridges on her abdomen, making her less appealing to predators. Their bodies are brown, white, or black, acting as camouflage. Colors do vary from one spider to the next.
Males do have sharp ridges and have more black and white coloration with a slender abdomen.
Females will sit upside down in their webs waiting for insects, males are never too far away.
9. Dark Fishing Spider
Female dark fishing spider
Scientific name: Dolomedes tenebrosus.
Common name: dark fishing spider.
The dark fishing spider is mostly found in wooded areas where they live on trees.
The female can grow to 26mm, while males grow to half the size. Their leg span can range up to 90mm.
They are dark brown to light brown with chevron markings and light stripes around the legs. Their banded legs are brown and black and red and black.
10. Banded Garden Spider
Female band garden spider
Scientific name: Argiope trifasciata.
Common name: banded garden spider, banded orb weaving spider.
Banded garden spiders create orb-shaped webs, which are often found on plants in garden beds. The spider sits upside down in the center of the web, waiting for prey to get ensnared.
They vary in color from black with yellow and white banding to red/brown with white banding. Their legs have the same colors in banding as th rest of the body with a rounded abdomen and furry neck region, which is covered in silver hairs.
Their webs are created low to the ground, usually between shrubs and tall grass.
11. Cross Orbweaver
Cross orb weaver
Scientific name: Araneus diadematus.
Common name: European garden spider, diadem spider, orangie, cross spider, crowned orb weaver, pumpkin spider.
Cross orbweavers are easy to identify with their white cross marking on a brown abdomen.
They are originally from Europe and make their way into North America, though they are not considered a pest. They are not harmful to humans and they are not a threat to the indigenous spiders.
These brown spiders have short hairs on their legs with brown and tan banding. There are long white hairs covering the cephalothorax and a white cross on the abdomen, which is made up of dots and dashes, sitting inside a V shape.
They sit upside down in their web waiting for prey to get ensnared, rebuilding their web every day.
They live in woodlands, gardens, evergreen forests, grasslands, semi-arid deserts, and savannas.
12. Northern Yellow Sac Spider
Northern yellow sac spider
Scientific name: Cheiracanthium mildei.
Common name: Northern yellow sac spider.
The Northern yellow sac spider has a tan or pale green body with dark chelicerae and palpi.
Adults can grow to 10mm in body length with each leg ending in a double claw. The front legs are double the length of the other legs.
They can and will bite if threatened, but their bites are considered mild.
These spiders are relatively common in Illinois, where they can be encountered both inside and outside the home.
13. Eastern Parson Spider
Eastern parson spider
Scientific name: Herpyllus ecclesiasticus.
Common name: eastern parson spider.
The Eastern parson spider has a white stripe on the abdomen that looks like a ruffled necktie, that was worn by clergymen in the eighteenth century.
These are fast, hairy, and medium-sized spiders that roam walls and grounds at night searching for food.
They are ambush predators and prefer woodland areas, though they have made their way into homes and buildings searching for food.
They are not dangerous, though some people have experienced an allergic reaction to the Eastern parson spiders’ venom.
14. American Nursery Web Spider
American Nursery Web Spider
Scientific name: Pisaurina mira.
Common name: American Nursery Web Spider.
American nursery web spiders have long abdomens, hard cephalothorax, and a high carapace. Their eight eyes are in two rows of four eyes each. The first row is straight with the second row creating a U shape on the back of the head. Some have a dark median band on their abdomens and others have two rows of spots.
They are wandering hunters, often found on the water margins on vegetation.
15. Asiatic Wall Jumping Spider
Female Asiatic Wall Jumping Spider
Scientific name: Attulus fasciger.
Common name: Asiatic Wall Jumping Spider.
This brown to black colored jumping spider has eight eyes and is small, growing to 4mm in body length.
Males and females are similar in body length with males having a more slender abdomen and larger palps.
These spiders originally come from Asia and were introduced to North America in the 1950s.
They are common inside and outside homes where they rely on artificial lighting that attracts insects.
16. Furrow Orbweaver
Scientific name: Larinioides cornutus.
Common name: furrow spider, furrow orb spider, foliate spider.
Furrow orbweavers have large bulb-shaped abdomens in black, gray, or red. The carapace of the abdomen has a light arrow that points towards the head. The legs have a similar arrow pattern.
Females are larger than the males, growing to 14mm, while the male grows to 9mm. They have an 18mm to 35mm leg span.
They have eight eyes arranged in a horizontal row of six eyes with an additional pair above.
The furrow orbweaver is found near water, with its webs created between shrubs or grass.
17. Triangulate Combfoot
Triangulate cobweb spider
Scientific name: Steatoda triangulosa.
Common name: triangulate cobweb spider, triangulate bud spider.
The triangulate combfoot has an orange to brown-colored cephalothorax and yellow legs, which are covered in tiny hairs.
Females can grow to 6mm in body length with bulb-shaped abdomens that are cream in color with brown zigzag lines that run down their backs.
They spend hours each day rebuilding and developing their webs. Below or on the web, you may see dead insects.
18. Common House Spider
Common house spider
Scientific name: Parasteatoda tepidariorum.
Common name: common house spider, American house spider.
Common house spiders are what creates the typical Halloween cobweb, a tangled mess you may find on the windows or in the attic.
These spiders have long and skinny legs with comb-like hairs. Their bulb-shaped abdomen is brown with white specks and dark lines and patches.
They are not aggressive and seldom bother humans. If bitten, you may experience pain for a couple of days.
19. Long-bodied Cellar Spider
Daddy long-legs spider
Scientific name: Pholcus phalangioides.
Common name: daddy long-legs spider, long-bodied cellar spider, skull spider.
Long-bodied cellar spiders have long, tubular abdomens and rounded bottoms with a tapered waist.
They are also commonly known as Daddy Long Legs.
These spiders are known for bouncing in their webs, creating a blur, making it harder for predators and humans to see them. They usually hang upside down in their webs waiting for insects to get entrapped.
They have tiny fangs, which are too small to inject any venom into a human.
20. Marbled Orbweaver
Scientific name: Araneus marmoreus.
Common name: marbled orbweaver, pumpkin spider.
Marbled orbweavers have a unique marbled pattern on their abdomen with an orange head and upper legs with black and white banding on the lower legs. Some are orange and yellow, some are black and orange, black and white, or black and yellow on their abdomens.
Females are double the size of the male and tend to remain hidden in their web.
They will fall to the ground if they feel they are in danger, staying hidden until the threat passes.
21. Wetland Giant Wolf Spider
Wetland giant wolf spider
Scientific name: Tigrosa helluo.
Common name: Wetland giant wolf spider.
The wetland giant wolf spider is an agile hunter with outstanding eyesight. Two of the eight eyes are large and prominent.
They live alone and tend to live alone. They do not spin webs, but are opportunistic hunters, pouncing on prey.
The female carries her egg sac attached to her spinnerets.
They can grow up to 1.38 inches (35mm) in body length with reflective tissue in the four larger eyes, which means you can see it easily when flashing a beam over the spider.
They rely on camouflage to protect them with a red, orange or yellow belly with black shading.
They hide under rocks and debris.
22. Grey Cross Spider
Gray cross spider
Scientific name: Larinioides sclopetarius.
Common name: bridge spider, gray cross spider.
The gray cross spider has white hairs that provide a silhouette of their heads with dark markings on their abdomens.
While the female is smaller in size, growing to 6.25mm in body length, while males grow to 7mm in body length, the female is considerably heavier.
They are often seen near buildings where there is an artificial light source.
23. Woodlouse Spider
Scientific name: Dysdera crocata.
Common name: woodlouse hunter, sowbug hunter, sowbug killer, pillbug hunter, slater spider.
Woodlouse spiders can grow to 15mm for females and 10mm in body length for males.
They have six eyes, orange to red cephalothorax and legs, and a shiny yellow-brown to beige abdomen.
They originally came from the Mediterranean and have been introduced to many countries around the world, where these spiders live on woodlice.
24. American Green Crab Spider
American Green Crab Spider
Scientific name: Misumessus oblongus.
Common name: American Green Crab Spider.
The American green crab spider can walk forwards, backward, and sideways with long front legs, which helps the spider capture pollinating insects.
These tiny spiders are bright green, enabling them to hide between the petals of a flower in plain view. Their slender abdomens have a kite to diamond shape with red bands on the side of the abdomen, which is only visible in some specimens.
They are wandering hunters and will climb plants to find food, often capturing insects considerably larger than themselves, such as butterflies and bees.
25. Brilliant Jumping Spider
Adult Male Brilliant Jumping Spider
Scientific name: Phidippus clarus.
Common name: Brilliant Jumping Spider.
Brilliant jumping spiders belong to the Salticidae family and are often found in old fields in Illinois.
They sit and wait upside down near the top of plants and then jump down to capture the prey.
They are at risk of being parasitized by the Californian wasp and have also shown great promise in controlling four-lined plant bugs, which are known to damage sweet basil crops.
26. Arrowhead Orbweaver
Scientific name: Verrucosa arenata.
Common name: triangle orb weaver, arrowhead spider, arrowhead orbweaver.
The arrowhead orbweaver is a member of the orbweaver family, creating webs up to two feet in diameter.
Females can grow to 14mm in body length with males being less than half the size.
Their abdomens range from yellow to white with some red areas.
Females have black, brown, or red legs and carapaces with their abdomen covered in a triangle of color. Males are smaller and don’t have a triangle on the abdomen.
27. Arabesque Orbweaver
Scientific name: Neoscona arabesca.
Common name: arabesque orbweaver.
This orbweaver is common in Illinois and is brightly colored with swirled markings on the abdomen.
They are common in fields, gardens, human structures, and forests.
Females are slightly larger than the males at 0.28 inches (7mm) in body length, while males grow to 0.24 inches (6mm) in body length.
Females build large webs, where she sits upside down in the center. She hides during the day.
They are non-aggressive and will only bite if they feel threatened.
28. White-banded Crab Spider
White-banded crab spider
Scientific name: Misumenoides formosipes.
Common name: White-banded crab spider.
White banded crab spiders can walk forwards, backward, and sideways.
These spiders have a white line running through the plane of their eyes. Their strong front legs enable them to capture prey much larger than themselves.
Females are larger than males with varying colors and patterns. Females can change color from white to yellow based on their surroundings, while males stay golden throughout their lives.
Females can grow to 0.44 inches (11.3mm) in body length and can have red, black, or brown markings o their bodies with a posterior ending in a rounded triangle shape.
Males grow to 0.13 inches (3.2mm) in body length with longer and darker front legs, compared to the rest of their bodies.
29. Broad-Faced Sac Spider
Broad-faced sac spider
Scientific name: Trachelas tranquillus.
Common name: broad-faced sac spider.
This outdoor spider only wanders into homes during the fall, when temperatures start to drop.
They are a solid color on their cephalothorax of red or dark brown, while the abdomen is tan or gray with a dull sheen. Their legs are brown, tan, or red with the front pair being darker than the rest.
These spiders can grow to 16mm in body length and are nocturnal hunters, hiding during the day.
30. Flea Jumping Spider
Flea Jumping Spider
Scientific name: Naphrys pulex.
Common name: Flea Jumping Spider.
The flea jumping spider is a gray and black mottled spider with orange on the side of the cephalothorax.
They are often encountered in tall grasses and wooded areas and are very common in hardwood forests, where leaf litter is abundant.
31. Rabid Wolf Spider
Rabid wolf spider
Scientific name: Rabidosa rabida.
Common name: rabid wolf spider.
The rapid wolf spider belongs to the Lycosidae family and can be encountered in Illinois.
They have two dark stripes on the cephalothorax and one stripe in the same color on their abdomens. The spider is has a yellow base color with females being larger than males. Their eight eyes are arranged in two rows of four.
32. Six-spotted Fishing Spider
Six-spotted fishing spider
Scientific name: Dolomedes triton.
Common name: six-spotted fishing spider, dock spider.
Six spotted fishing spiders are large with distinctive markings. Their eight eyes provide them with excellent vision. The body is brown to gray with a white to pale cream stripe that runs down either side of the cephalothorax. The abdomen has light spots and light lines down the side of abdomen. They have six distinct spots under their belly.
Females are larger than the male growing to 0.79 inches (20mm) in body length with a 60mm leg span. Males grow to 0.51 inches (13mm) in body length.
They are semi-aquatic and prefer ponds, lakes, and slow-moving streams.
33. Golden Jumping Spider
Female emerald jumping spider
Scientific name: Paraphidippus aurantius.
Common name: emerald jumping spider, golden jumping spider.
Golden jumping spiders are also known as emerald jumping spiders, a solitary hunter that is large and known for being able to jump more than four times its body length.
They are green or black with white side stripes on the sides of the cephalothorax and a white border on the top of the abdomen. They have midline hairs with small dots on their side.
They are harmless to humans and a bite is no worse than a bee sting.
34. Thin-spined Jumping Spider
Female Thin-spined Jumping Spider
Scientific name: Tutelina elegans.
Common name: Thin-spined Jumping Spider.
The thin-spined jumping spider is a small spider that lives under stones and in bushes and tall grasses.
They have white hairs and green scales over their bodies. The cephalothorax is larger than the abdomen with a red to brown colored plate covering the cephalothorax. Their eyes are arranged in four pairs. Their short legs are striped and adapted for jumping.
Females are larger than males and grow to 6mm in body length and 9mm in leg span. They are very similar to the male but their color may be darker and their abdomen larger.
35. Putnam’s Jumping Spider
Female Putnams jumping spider
Scientific name: Phidippus putnami.
Common name: Putnams jumping spider.
The Putnams jumping spider belongs to the Salticidae family and can jump more than four times its body length.
They are hairy spiders with four black tufts of hair above the eyes and on the sides of the head.
They live in a wide variety of habitats from forests and parking lots to gardens, fields, and parks. They are known to make their way into homes.
They are not dangerous and will bite if they are handled too roughly.