Spiders Common to Southeast Michigan

Garden spiders have venom but rarely bite unless threatened.

Michigan provides a home to more than 500 of the approximately 2,500 species of spiders found in the USA, according to Michigan State University Extension. Cobwebs in your home indicate a spider lived there and probably lives in a new web now. Fortunately, the bites of most species of spiders found in Michigan do not cause serious injury to humans.

Basics

Although all spiders have four pairs of legs, many arachnids other than spiders, such as scorpions, ticks and mites, also posses eight legs. Spider bodies include two sections, not one like a tick or harvestman (also commonly called a daddy longlegs) or an insect's three sections. Spiders in Michigan range in size from the tiny micro phantid to large garden spiders, according to Michigan State University Department of Entomology.

Region

Most spiders found in Michigan live all over the state, but not all. However, climate change, shipping boxes and containers and other measures make it possible to find spiders in the southeast portion of Michigan that normally reside elsewhere. Climate change may result in rarely seen spiders, such as the brown recluse, moving into Michigan, according to the University of Kansas. Therefore, lists of spiders in the area may change depending on climate and other conditions.

Common House

Common spiders found living in homes in Michigan include cobweb, cellar and yellow house spiders. The small tan, gray or yellow cobweb spider builds new webs when it fails to catch food in the previous one. Cellar spiders, or Pholcids, possess long legs and often build webs in dark, moist places such as basements and crawlspaces, according to Grounds Services, Inc. Although it typically lives outside, the yellow house or yellow sac spider may build indoors in the southeast region of Michigan. It delivers a bite that causes pain and necrosis, similar to a brown recluse, according to Michigan State University Extension.

House Visitors

Scary looking wolf spiders, which may bite if harassed, generally come into a house by accident, not to live there, assures Michigan State University Department of Entomology. Hairy, medium-sized jumping spiders possess shorter legs and catch prey by jumping on them. Usually they live outdoors, but sometimes search for prey around your windows or doors.

Poisonous

Spiders inject poison into their prey; therefore, technically all spiders possess some poison. Most spiders in southeast Michigan rarely bite humans and do not deliver enough poison to cause damage unless the person is allergic, very young, old or sick. Unfortunately, the northern black widow spider, identifiable by the hourglass marking on the abdomen, makes its home in southeast Michigan. The bite from a female black widow, while generally not life-threatening, may cause severe reaction in some people and requires medical attention, according to the Michigan Department of Natural Resources. Brown recluses generally do not live in Michigan, but a documented case and possible migration with climate change makes it possible.

Outdoors

Southeast Michigan provides a home to many outdoor spiders including orb weavers, crab spiders, the grass funnel weaver spiders and nursery web spiders. One orb spider, Argiope aurantia, also called the black and yellow garden, writing or corn spider, may bite if provoked but delivers minimal poisons that affect people, according to the University of Michigan Museum of Zoology.

References

• Michigan State University Department of Entomology: Some Spiders
• Michigan State University Extension: Spiders-Biology and Control
• Ground Services, Inc.: Spiders
• University of Kansas; Research: Brown Recluse Spider Habitat May Alter With Climate Change; March 28, 2011
• University of Michigan Museum of Zoology; ADW-Argiope Aurantia-Information; George Hammond

Resources

• Read this Article in Spanish
• Michigan State University Department of Entomology: Spiders of Medical Importance
• Burke Museum of Natural History & Culture: Spider Myths: Home
• InsectIdentification.org: Insect and Spider Identification-Details on North American Bugs
• University of Michigan; BioKIDS Invertebrate Identification Guide; 2004