#10: Forest Wolf Spider
The forest wolf spider, Hogna frondicola, is a member of the wolf spider family Lycosidae. You can find these spiders in Illinois as well as throughout the rest of the United States and Canada. Forest wolf spiders sport a leg span of around 50 millimeters, with females typically measuring larger than males. Like other members of their family, they possess long legs well adapted for running. They feature a distinctive, wide grey stripe down the center of their carapaces. Meanwhile, the rest of their carapaces look dark grey, while their abdomens and legs are light grey. Rather than relying on webs, forest wolf spiders use their keen eyesight and agility to catch prey. They typically hunt at night and retreat to underground burrows during the day. Due to their large size, they can deliver a painful bite, but their bite is not medically significant.
#9: Ridge-Faced Flower Spider
Also known as the white-banded crab spider, the ridge-faced flower spider belongs to the crab spider family Thomisidae. If you’re looking for these spiders in Illinois, you’re most likely to find one resting on the leaves or petals of a flower. Female ridge-faced flower spiders normally measure 5 to 11 millimeters long, while males measure around 2-3 millimeters long. Their carapaces normally appear yellowish-green, with a yellow midband surrounded by purplish-brown sides. Meanwhile, their abdomens are often solid yellow, but may also feature a purplish-brown, V-shaped marking. They get their name from the small white or yellow ridge located below their eyes. Ridge-faced flower spiders can change their color to match their surroundings. This aids them with hunting, as they use sit-and-wait tactics rather than webs to capture prey. Due to their small size, their bite is not usually able to pierce human skin.
#8: Orchard Spider
The orchard spider is a member of the long-jawed orb weaver family Tetragnathidae. You can find these spiders in Illinois as well as throughout the eastern United States. Most orchard spiders measure between 3.5 and 7.5 millimeters long, with males measuring smaller than females. They have distinctive leaf-green legs and sides. Meanwhile, their undersides feature black and yellow dots and their tops are silver with black and brown stripes. Additionally, they sport bright yellow, orange, or red spots near the rear of their abdomens. Orchard spiders often hang facing downward in their horizontally-oriented webs. As their name implies, they often build their webs in wooded areas including man-made ones such as orchards. They prey on many garden pests and their bite is not threatening to humans. As a result, many people consider them beneficial and like to keep them around.
#7: Northern Black Widow
The northern black widow, Latrodectus variolus, is a member of the cobweb spider family Theridiidae. It is one of the most venomous spiders in Illinois and is also widely distributed throughout the eastern and northern United States and southern Canada. Female northern black widows measure from 9 and 11 millimeters long, and males measure 4 to 5 millimeters. Like other black widows, they appear mostly black aside from a red hourglass-shaped marking on their abdomens. However, the hourglass is rarely intact, which is a distinctive difference from other black widows. Northern black widows carry venom that is capable of causing latrodectism. If bitten, common symptoms include pain, sweating, vomiting, and muscle rigidity. On rare occasions, their bite can prove fatal. That said, most people that die from northern black widow bites are either very young or severely immunocompromised.
#6: Tan Jumping Spider
Platycryptus undatus, or the tan jumping spider, is one of several species of jumping spiders in Illinois. It ranges from the central United States to the east coast and from Canada in the north to Texas in the south. Female tan jumping spiders measure from 10 to 13 millimeters long and males measure around 8.5 to 9.5 millimeters in length. They feature a distinctive pattern on their abdomens that consists of a series of V-shaped markings running from front to back. These markings appear light grey or beige, while the rest of their bodies are grey with black mottling. Tan jumping spiders do not build webs to catch prey. Instead, they actively hunt using their keen eyesight and quick jumping ability to stalk and subdue their prey. They aren’t generally aggressive but may bite if cornered or threatened. That said, their bite is not considered medically significant.
#5: Woodlouse Spider
Also known as the woodlouse hunter, pillbug hunter, or sowbug killer, the woodlouse spider is an arthropod with many names. A member of the family Dysderidae, it is a cosmopolitan species found throughout much of the world. Female woodlouse spiders typically measure 11 to 15 millimeters, and males measure from 9 to 10 millimeters long. They possess 6 rather than 8 eyes, and sport disproportionally large chelicerae, or mouthparts. Their legs and bodies are orangish-red, while their abdomens appear yellowish-brown or grey. If you’re looking for these spiders in Illinois, you’re most likely to encounter them under logs, bricks, or anywhere you’re likely to find woodlice. As their name implies, their diet consists primarily of woodlice, although they also prey on centipedes and other spiders. Their bite is quite powerful and can therefore be rather painful, but otherwise poses little threat to humans.
#4. White-Banded Fishing Spider
Dolomedes albineus, or the white-banded fishing spider, belongs to the nursery web spider family Pisauridae. You’re most likely to find these spiders in Illinois near streams, ponds, or other bodies of water. Female white-banded fishing spiders can reach up to 23 millimeters long. Meanwhile, males can grow up to 18 millimeters in length. They vary in color, although most specimens appear brown or mossy green with dark markings. Their name comes from the white band that runs across the space below their eyes, around the jaws, and sometimes even around the entire carapace. White-banded fishing spiders hunt for small vertebrates as well as insects. They can dive under the surface of the water to catch tadpoles and small fish and are able to run across the surface of the water. Despite their large size, their bite is not considered medically significant.
#3. Marbled Orb Weaver
The marbled orb weaver, Araneus marmoreus, is one of the most visually striking spiders in Illinois. It is found throughout North America, particularly in wooded areas where it likes to build its webs. Female marbled orb weavers measure up to 18 millimeters long, while males measure about half that size at 9 millimeters long. They also go by the name pumpkin spiders, because their large, orange abdomens resemble a pumpkin. Their abdomens typically appear orange with black or brown marbling, although some look pale yellow with a dark patch near the rear. Marbled orb weavers build vertically-oriented webs with a silk retreat in the corner where they hide during the day. Although they are quite large, they are not known to be aggressive, and their bite poses no danger to humans.
#2: Black Lace-Weaver
The black lace-weaver, Amaurobius ferox, is a nocturnal spider in the family Amaurobiidae. Originally native to Europe, it is now also found in Illinois as well as throughout North America and New Zealand. You can typically find it in dark, moist spaces such as basements or under logs or stones. Female black lace weavers measure from 11 to 16 millimeters long, and males measure 8 to 10 millimeters long. Their bodies look predominantly black, but may also appear dark red or brown. They have round abdomens with yellow, pale markings that sometimes appear in the shape of a skull. Black lace weavers get their name from lace-like webs. Their webs are made of thin, wooly, extremely sticky silk that excels at catching prey. They have been known to bite people, the effects of which are equatable to a mild wasp sting.
#1. Eastern Parson Spider
The eastern parson spider, Herpyllus ecclesiasticus, is a member of the ground spider family Gnaphosidae. As its name implies, it is distributed throughout the eastern half of North America. Most specimens measure from 10 to 20 millimeters long, with males measuring smaller than females. They appear predominantly black or dark grey and are covered in fine hairs. Their abdomens feature a white stripe that resembles a cravat, a type of necktie worn by 18th-century clergy, also known as parsons. Eastern parson spiders do not use webs to catch prey. They prefer to ambush their prey and can run incredibly quickly in pursuit of insects. Although their bite is not lethal, it is known to be quite painful. Since they often prey on household pests, most people consider them beneficial and tend to leave them alone.
