Medically Important Spiders in Nebraska: The Black Widow and Brown Recluse

Photo of adult Brown Recluse spider magnified. (Photo by UNL Dept. of Entomology)
Photo of adult Brown Recluse spider magnified. (Photo by UNL Dept. of Entomology)

By Kait Chapman, Extension Educator in Lancaster County

There are many species of spiders that can be found around and indoor homes and buildings. While most of these spiders are relatively harmless, there are two to be on the lookout for: the black widow and the brown recluse.

Black widow spiders are only occasionally found in Nebraska. These spiders create tangled, messy webs of sticky silk and are easily identified by the red hourglass shape on the underside of the adult female’s abdomen. Male black widows, which are often eaten by the female, are much smaller and gray or brown in color.

Black widow venom contains a nerve poison that causes severe pain at the site of the bite which soon spreads throughout the body. Other symptoms may include elevated blood pressure, nausea and difficulty breathing. Bites, albeit rare, most often occur when a female is protecting an egg sack in her web.

While their size can vary, brown recluse spiders are approximately the size of a quarter, with lackluster coloring and long, thin legs. Brown recluses have a characteristic violin or fiddle-shaped marking on their carapace, which is used to distinguish them from other brown spiders that may be found indoors.

As their name suggests, brown recluse spiders are reclusive and prefer to stay away from human activity in the home. They are most often found in quiet, undisturbed areas like basement corners, closets, garages, etc. Most brown recluse bites occur when putting on clothes or shoes and, inadvertently, trapping a spider against skin. Brown recluse venom contains a cytotoxin that causes large ulcerous sores around the bite site.

It is impossible to diagnose a spider bite by the presence of a bite alone. If you suspect you have been bitten by a brown recluse or black widow, seek medical treatment as soon as possible.

Nebraska Extension in Lancaster County offers free insect and spider diagnostic services, including identification and management recommendations. Residents may mail or bring their samples to 444 Cherrycreek Road, Suite A, Lincoln, NE 68528 during office hours M-F, 8 a.m.–4:30 p.m. Please address any envelopes to Kait Chapman. You may also email photos to