Black Widow
The southern black widow, Latrodectus mactans, and its relatives live across the entire United States. Other widow species found in Alabama are the western black widow, L. hesperus; the northern black widow, L. variolus; and probably the brown widow, L. geometricus. Their coloration varies considerably. For proper identification, an expert may be needed to examine mature specimens.
Widow spiders are found in protected cavities outdoors. Around houses, they may live in privies, garages, cellars, furniture, shrubbery, ventilators, rain spouts, gas and electric meters and other undisturbed places. Widow spiders also may be seen in cotton fields and occasionally vegetable gardens.
Like most spiders, widow spiders are shy and retiring. People are bitten occasionally when they accidentally disturb a hidden spider or its web. To avoid hidden spiders, take care when putting on seldom-worn shoes or clothing.
Description and life cycle
Widow spiders are typically jet black, but their color can vary considerably. Males and juveniles tend to show more color, with orange, red and white markings on the back and sides. On the underside of their rounded abdomen are two reddish triangles that may be united to form an hourglass shape.
Some individuals have irregular or spot-like markings; others have none at all. Adult widow spiders average 11/2 inches long and have eight eyes in two rows, a common spider pattern.
Females lay eggs in a loosely woven cup of silk. The 1/2-inch-long oval egg sacs hold from 25 to 900 or more eggs, which incubate for about 20 days, depending on temperature and time of year. Spiderlings usually stay near the egg sac for a few days after they emerge, when cannibalism is prevalent. Surviving spiderlings disperse by “ballooning.” They spin a single silk thread which is caught by the wind, which carries them to a new location. When about one-third grown, they establish themselves in a protected place and build loosely woven webs.
The spiders usually remain in their rather coarse, irregular, tangled webs for the rest of their lives. Over time they extend their webs and capture progressively larger prey. Males eventually leave their webs to find females for mating. Contrary to popular belief, most females do not normally eat the males after mating. This habit, found in a few species of widow spiders from other areas, gives the group its name.
Bite symptoms
If noticed at all, a widow spider bite may feel like a pin prick. Usually the bite location is indicated by a slight local swelling and two red spots surrounded by redness. The reaction is systemic and pain becomes intense in one to three hours, continuing for up to 48 hours. Symptoms include tremors, nausea, vomiting, leg cramps, abdominal pain, profuse perspiration, loss of muscle tone and rise in blood pressure. The toxin can also cause breathing difficulties and sometimes unconsciousness. However, less than 5% of people bitten by widow spiders die.
