When the outdoor temperatures begin to drop during the fall months, spiders move indoors for warmth. Utah and the Intermountain West have black widow spiders, and they are encountered more often during the fall season than any other.
The web of a black widow is an extensive, irregular, shaggy trap for the insects she normally eats. The black widow rarely leaves the web and stays close to her egg masses if present. She will aggressively defend the egg mass and bites if it is disturbed. Despite its aggressive reputation, this spider often attempts to escape rather than bite when she is not guarding eggs.The term "black widow" is actually inaccurate because only three of the five species of widow spiders are actually black, the others being brown and gray. The female spider is the larger of the sexes. The female has a unique hourglass mark, usually red, on the abdominal surface. Newly hatched spiders are almost entirely red. Males have white stripes along the outside of the abdomen. Only adult females can inject venom. The bite usually feels like a mild pinprick.
Most spider-bite victims never see the spider. Since the species helps determine the treatment, the dead spider - if it can be found - should be taken with the victim to a hospital emergency department.
Two tiny red marks with a white and reddish-blue border help identify a black widow spider bite. Victims often notice it only after the onset of localized symptoms, which may occur within 30 minutes of the bite and include extremity pain, redness, itching and swelling.
The venom of a female black widow spider is neurotoxic and very potent, affecting the nervous system. Cramping pain in the thighs, abdomen and chest within an hour of the bite is common. A boardlike abdominal rigidity occurs. Other symptoms such as muscle twitching, tremors, facial flush and swelling, nausea, vomiting and fever often follow.
If you are with someone who has been bitten by a black widow spider, stabilize the affected area and keep the victim as still as possible. Movement increases circulation, which hastens the spread of venom throughout the body. An ice pack can help relieve pain.
If the bite is detected within the first 15 minutes, a Sawyer's Extractor - a portable syringelike pump that is sold at camping supply stores - can be used to draw out the venom. To use it, place the device directly over the puncture marks and apply suction. But start right away; once the venom circulates through the bloodstream, the Extractor is ineffective. The victim still needs to be taken to the hospital for medical treatment.