Black widows are notorious spiders identified by the colored, hourglass-shaped mark on their abdomens. Several species answer to the name, and they are found in temperate regions around the world.
To feed, black widows puncture their insect prey with their fangs and administer digestive enzymes to the corpses. By using these enzymes, and their gnashing fangs, the spiders liquefy their prey’s bodies and suck up the resulting fluid.
Biology & Behavior
The black widow is a common species in many parts of Utah. Black widows produce a loose web and prefer to inhabit dark, undisturbed areas. Typical locations of black widow nests include locations such as shrubbery, around log piles, in crawl spaces, under porches, in garages, and around piled debris.
Essentially, all human bites occur from the female black widow often as she is guarding her egg sack. A grown female is about 1/2 inch in length and appears shiny black or dark brown with a spherical abdomen. Most black widows also have orange-red markings on the underside of the abdomen, sometimes appearing as an hour glass. However, these markings may be reduced an even absent amount many of the black widows.
The venom of the black widow spider is a nerve poison that produces distinctive symptoms. Often the original bite is not painful. It then produces a burning sensation with local swelling and redness. Pain may become intense in one to three hours and last up to 48 hours. Cramping of the legs, arms, and chest may follow. The abdominal muscles become rigid in many cases.
Black widow bites should receive prompt medical attention. Although fatalities are very rare, symptoms are very painful. Antiserums are available and injections of calcium gluconate can help to relieve symptoms.