Spiders in Michigan: A Guide to the Most Common Species

Michigan is home to a diverse array of spider species. These eight-legged creatures can be found in backyards, forests fields, and wetlands across the state. While some spiders get a bad reputation most are harmless to humans and play an important role as predators in the ecosystem.

This article will explore some of the most commonly encountered spiders in Michigan, providing tips on identification and information about their natural history.

Jumping Spiders

Jumping spiders are active hunters that don’t build webs to catch prey. Instead, they stealthily stalk their prey and pounce when ready to attack.

Some common jumping spiders in Michigan include

• Bold Jumping Spider A small spider with a white stripe across the upper abdomen Often found indoors

• Tan Jumping Spider: Brown or tan spiders with the ability to jump up to 40 times their body length.

• Zebra Jumping Spider: Distinctive black and white striped appearance. Grows up to 9mm long.

• Dimorphic Jumping Spider: Comes in two color forms – tan with red or black with yellow legs. Very small in size.

Jumping spiders are harmless to humans. They occasionally wander indoors but don’t usually stay long. Their venom is not dangerous.

Orb Weavers

Orb weavers spin large, circular webs to ensnare flying insects. The spider waits in the center or along the edges of the web for vibrations signaling trapped prey. Some common orb weavers in Michigan are:

• Cross Orbweaver: White cross shape on the abdomen. Introduced from Europe.

• Marbled Orbweaver: Abdomen marked with orange, yellow, black and white. Most active in fall.

• Shamrock Orbweaver: Black and white striped legs. Yellow, red or purple abdomen.

• Banded Garden Spider: Large black and yellow spider up to 3 inches across. Makes huge webs.

• Furrow Orbweaver: Gray, black or red spiders under 1cm long. Found near water.

Though some can deliver a painful bite, orb weaver venom is not considered medically significant for humans.

Wolf Spiders

Wolf spiders are ground-dwellers that don’t use webs to catch prey. They hunt and ambush prey. Some wolf spiders in Michigan include:

• American Grass Spider: Brown spiders with two black stripes down the body.

• Northern Wolf Spider: Large, hairy spiders up to 1 inch long. Excellent eyesight.

• Shoreline Wolf Spider: Live along beaches and riverbanks. Well-camouflaged in sand.

• Rustic Wolf Spider: Dark brown or black spiders found in grasslands. Grow over 1 inch long.

Wolf spiders rarely bite unless handled. The venom can cause mild pain and swelling but is not very potent.

Nursery Web Spiders

Nursery web spiders build protective webs for their egg sacs and young. The female guards the eggs and spiderlings until they are ready to disperse. Examples in Michigan include:

• American Nursery Web Spider: Females carry egg sacs in their jaws while seeking ideal nursery sites.

• Fishing Spiders: Build silk nursery mats for their eggs near water.

Nursery web spiders pose no threat to humans. Their venom is mild.

Crab Spiders

Crab spiders have a laterigrade walking style, allowing them to walk sideways and backwards with ease. They don’t build webs to catch prey. Some crab spiders in Michigan are:

• Goldenrod Crab Spider: Variable color allows camouflage against flower petals. Ambush pollinators.

• Northern Crab Spider: Red stripes on abdomen. Lie in wait on flowers to catch prey.

• Green Crab Spider: Neon green color. Hide on plants and flowers stalking insects.

Crab spider bites are generally no worse than a bee sting for humans.

Sac Spiders

Sac spiders get their name from the silk pouches or sacs they build for shelter. They lie in wait within the sac to ambush prey. Examples in Michigan include:

• Yellow Sac Spider: Pale green to tan spiders with dark brown fangs. Found indoors and out.

• Broad-Faced Sac Spider: Reddish-brown outdoor spiders that wander indoors in fall.

• Leaf-Curling Sac Spider: Brown spiders that curl leaves with silk for egg sacs.

Sac spider bites can be painful but are not medically significant.

Cobweb Spiders

Cobweb spiders build messy, tangled webs in dark corners of garages, basements, attics and other sheltered spots. Cobweb spider species in Michigan include:

• Common House Spider: Builds classic Halloween-style webs. Harmless to humans.

• Candy-Striped Spider: Distinctive red stripes on white, green or cream abdomen. Introduced from Europe.

• Black Widow Spider: Venomous but bites are rare. Red hourglass shape on belly.

Most cobweb spiders pose no threat, but black widows should be avoided and caution used around their webs. Seek medical care if bitten.

Fishing Spiders

As their name suggests, fishing spiders hunt along the water’s edge. They detect vibrations on the surface to detect prey. Some fishing spiders found in Michigan are:

• Dark Fishing Spider: Large, up to 3 inch legspan. Found near water.

• Six-Spotted Fishing Spider: Brown spider with light spots on abdomen. Live near lakes and rivers.

• Striped Fishing Spider: Brown body with light striped legs. Eat tadpoles and small fish.

Fishing spiders are generally harmless but can deliver a painful defensive bite if threatened.

Identifying and Appreciating Michigan Spiders

With over 650 species documented in the state, Michigan is home to an impressive diversity of spider species occupying all sorts of habitats. Learn how to identify the web types and hunting strategies of common families. Marvel at the complex behaviors and strategies spiders have evolved to thrive. And appreciate the role they play in controlling insect pest populations. With increased understanding, even the most fearful spider skeptics can learn to coexist with these fascinating creatures.