Luckily, most spiders in Michigan are not dangerous; including the largest species. They may look intimidating, but they’re really just going on their own and would rather avoid interacting with humans. In fact, they are of ecological importance, helping to keep the food chain active. Nonetheless, there are only two venomous spider species in Michigan; the brown recluse spider and black widow spider, and they are rarely encountered. Below, you’ll discover six of the largest spiders found in Michigan and how you can easily identify them.
6 Largest Spiders in Michigan
Wolf Spider
An adult wolf spider can grow up to 1.2 inches, making it the largest species of spiders in Michigan. With eight eyes arranged in three rows, wolf spiders are known for their excellent eyesight. The presence of two very large, prominent eyes in the middle row differentiates them from nursery web spiders. Wolf spiders also carry their eggs sacs by attaching them to their silk-spinning organ (called spinnerets). They do not make webs to capture prey, instead, they hunt their prey on the move, like wolves (hence their name). These large, hairy spiders are widely distributed in both coastal and inland habitats. However, you need to be careful around them because they are venomous but their venom is not fatal. Symptoms of their bites include swelling, mild pain, and itching.
Fishing Spider
One of the largest spiders in Michigan, the fishing spider has a pale to dark brown color with several markings and lighter stripes around its legs. Females are usually larger than males, with the female bodies being 15–26 mm (0.59-1.02 in), while the males are 7–13 mm (0.28-0.51 in). The legs are banded with brown/black rings on the femora and reddish-brown/black rings on the tibia. They are usually found near water, in wooded areas, and on trees. They are nocturnal hunters, feeding on aquatic insects or small fishes near water–which is how they got their name. Though it may look intimidating, a fishing spider is generally harmless. It can bite humans but will usually run from people. In most cases, the bite is not severe.
Nursery Web Spider
The nursery web spider can be found throughout the world except in extremely dry or cold environments. In short, they are common just about everywhere, with a special preference for water, forests, low shrubbery, and high weeds. Adult individuals of this species may reach up to 15mm (0.59 inches) in length, including legs. Interestingly, the legs of the male are longer in relation to the body size of the female. They’re often mistaken for wolf spiders. This confusion can be avoided by checking their eyes, which are all about the same size, unlike wolf spiders’. In addition, female nursery web spiders carry their egg sacs with their jaws and pedipalps, unlike wolf spiders. However, both species are roaming hunters that don’t use webs for catching prey, though female nursery web spiders make a web to protect their young.
Black and Yellow Argiope Spider
As its name suggests, the black and yellow Argiope spider has distinctive yellow and black markings on the abdomen and mostly white or gray head. The females of this species are larger than the males. Female Argiope spiders grow to 1.5 inches long, while the males are normally 0.75 inches long. They can be found in trees, gardens, or fields. Argiope spiders make beautiful webs with a unique circular shape. The webs have a thick zigzag of silk in the center which help camouflage the spider from predators. They are not aggressive, and their bite is harmless. Argiope spiders are frequently encountered in many gardens in Michigan, especially during the day when they’re active.
Giant House Spider
Mainly dark brown in color, giant house spiders are among the largest spiders in Central and Northern Europe. The female body size can reach 18.5 mm (0.73 in) in length, while males have a slightly smaller body at around 12 to 15 mm (0.47 to 0.59 in) in length. They have extremely long legs that are banded with rings. The bite of this species does not pose a threat to humans or pets, and they are generally reluctant to bite, preferring instead to hide or escape. With speeds clocked at 1.2 mph, the giant house spider held the Guinness Book of World Records for spider with the fastest speed until 1987 when it was displaced by solifugids.
Grass Spider
Grass spiders are also called funnel web spiders because of the funnel-shaped web they weave. One grass spider left undisturbed can create a web that measures over 1 yard! These spiders appear brown with black, tan, and gray markings. The larger specimens can grow to about 19 mm in body length and may be recognized by the arrangement of their eight eyes into three rows. The top row has two eyes, the middle row has four eyes, and the bottom row has two eyes. Fortunately, they are generally harmless to humans. Although most spiders use their webs to catch prey, the grass spider’s web does not have a sticky surface. The spiders make up for that with their fast running. They are one of the fastest-running spiders in Michigan.
