How to Identify Common Wyoming Spiders

How to Identify Common Wyoming SpidersMany people are afraid of spiders without realizing that these creatures only pose a threat to us when they feel threatened. Most spiders in the West are benign, but Wyoming has three types that residents and visitors should know about: the black widow, brown recluse and aggressive house spider.


Difficulty: Moderate

What to do:

Things You’ll Need:
  • regional guidebook
  • small insect container, such as a glass jar with holes in the lid
  • magnifying glass
  • camera
Step 1
Study pictures of the spiders you want to avoid so you can tell the difference between those spiders and their nonvenomous cousins. Regional guidebooks on insects published by the National Audubon Society or the National Wildlife Federation can help you identify spiders.
Step 2
Beware of small, shiny, black or brown-black spiders with round, bulging abdomens. These are black widows. Females (the venomous ones) are about a half inch in length and the males are about half this size. Black widows build irregular webs in vacant, quiet, dark areas such as crawlspaces, outdoor sheds and bushes. These spiders are known for the hourglass-shape marking on their abdomens. The males have a red one and the females have one that is reddish orange. According to the University of Wyoming's College of Agriculture, the venom from a black widow affects the nervous system and causes burning, swelling, redness and muscle cramping.
Step 3
Look for brown recluse spiders, sometimes called fiddlers, in eastern Wyoming. These are dark brown to yellow-brown in color and are distinguished by fiddle-shaped markings. Brown recluses are a quarter inch to half inch in length. With the aid of a magnifying glass, you can see that these spiders have only three pairs of eyes; most spiders have four. A bite from a brown recluse can cause burning, blistering, redness and swelling. These spiders can be found in boxes, shelves, ventilation systems, storage areas, carpets, cracks, closets and attics.
Step 4
Aggressive house spiders are also known as hobo spiders in Uinta County, Wyoming. They spin funnel-shaped webs and move quickly over flat surfaces, avoiding walls and ceilings. Their bites cause a reaction much like that of the brown recluse. Aggressive house spiders are nearly 2 inches in length, have no rings on their legs and are a sandy or tan color.
Step 5
Take a photograph, if possible, of a spider you are trying to identify. If it has bitten you and you are unsure what kind of spider it is, try to capture it in a jar or container so it can be properly identified and the bite can be treated appropriately. If you suspect one of these three venomous spiders is responsible for a bite, seek medical treatment right away.
Step 6
Common and harmless species found in Wyoming include wolf spiders and jumping spiders. Most are harmless. Use your guidebooks to identify other spiders you might discover by their coloration, markings, size, shape, habitat and web type.

Tips & Warnings

Do not attempt to handle a spider if you are unsure what kind it is.

Article Written By Naomi Judd

Naomi M. Judd is a naturalist, artist and writer. Her work has been published in various literary journals, newspapers and websites. Judd holds a self-designed Bachelor of Arts in adventure writing from Plymouth State University and is earning a Master of Fine Arts in creative writing from the University of Southern Maine.

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