How to Identify Spiders in Pennsylvania

Spiders can be both interesting and frightening creatures. They help control the local insect population, but they are also caricatured in modern popular culture, leading some people to be more fearful of them than might be warranted. What most people don't know is that the vast majority of spiders will avoid contact with humans. Even among those spiders that bite, the affected area is often only mildly irritated. Being well-informed about the spider populations in your area can keep you from either overreacting or not being amply prepared in case of a bite.

Things You'll Need

• Magnifying glass

Instructions

Varieties of Spiders

1. Look for the grass spider in grassy areas, tall weeds or ivy. These spiders tend to be from 9 to 20 millimeters long with brown bodies, often with two stripes of darker brown from the head to the abdomen. They build sheet-like webs with a tunnel that the spider uses for seclusion from prey or attackers. There are no recorded incidents of grass spider bites affecting humans adversely.

2. Search for the yellow garden spider is in bushes or on the eves of buildings where they can construct their large, orbed webs. These spiders are identified by brightly colored yellow or orange blotches on their abdomen and their length (some are as large as 28 millimeters). Also, their webs can be identified by a distinct zig-zag shape down the middle. Bites are rare and only cause as much discomfort as a bee sting.

3. Carefully rummage through leaves and wood debris for the broad-faced sac spider. It is occasionally found indoors during the mid-to-late autumn. Its legs are thick, covered in a shell-like substance, and brown. The abdomen is lighter, often grey in color. Bites from this spider can be painful, and occasionally result in an infection, particularly if a person is sensitive to insect or spider venom.

4. Be careful to avoid Agrarian sac spiders. They can be found in similar locations as their cousins (above) in leaf and foliage litter outside, and occasionally are found indoors. These spiders can be up to 10 millimeters long and are a yellow or beige color, with dark colored mandibles. Often, their front legs are significantly longer than the back. These spiders are aggressive and will bite without being provoked. Reactions are usually mild, though some reports have associated severe symptoms that are similar to black widow bites (though less severe).

5. Be very cautious if you find a black widow near your home. The black widow is shiny, black in color with a red hour-glass shape on its abdomen, and can be 25 to 35 millimeters long. Though they are the most infamous of spiders, deaths resulting from black widow bites are not commonly fatal--usually only in cases involving the elderly or small children. The bite is not often painful until a few hours after the event, when symptoms including nausea, chills, fever or motor failure may ensue.

Tips & Warnings

• Comparing your spider findings to an internet image search can be helpful along with comparing them to written descriptions. Taking a picture of your finding can help you preserve and compare your findings with other people in your area.

• Most spiders will not bite unless they are provoked. Do not handle or provoke spiders.

• In the case of a spider bite that begins exhibiting more severe symptoms, seek medical help immediately. Often, if a specimen can be safely procured, it will help in the diagnosis of the bite. Keep the spider in a safe, enclosed container for classification at the medical facility.

References

• Penn State Common Spiders (.pdf)

Resources

• Spiders in the UK
• Spiders in the Southwest Desert