focus on nature

focus on nature She May Be a Femme Fatale, but This Creature Is No Merry Widow

In her silken chambers, the lady waits alone, garbed in glossy black with a splash of crimson trim. She's nearly blind, poor dear, but possessed of such exquisitely tuned touch receptors that she's at once aware of visitors, however small or stealthy. Despite her sedentary life-style and shy nature, she has a perfectly terrible reputation. Latrodectus, or "robber-biter," she's called by scientists, but we who fear and shun the lady dubbed her the black widow.She is among the most notorious of spiders, a breed of creepy crawlers that cohabit with humanity in mutual unease. Her common name and notoriety derived from her sometime habit of devouring her consort following mating, an unsavory (to us) practice engaged in by many female spiders, if hungry. Her reputation is further tarnished by the fact that the black widow and her sisters in genus Latrodectus are among the few spiders dangerous to people.

Nearly all spiders are venomous, but the black widow's neurotoxic venom is, drop for drop, more potent than the rattlesnake's. Indeed, her venom is among the most highly toxic of all venomous creatures. (While the male black widow has poison glands as well, the female bears the blame for causing injuries to animals and people.) Her bite, though seldom fatal, is not to be trifled with.

An initial pinprick of pain precedes a searing, intense pain that moves from the bite site to concentrate in the abdomen and legs. Additional symptoms may include dizziness, nausea and vomiting, headache, sweating, tremors, labored breathing, even shock. Left untreated, the symptoms usually last for two or three days and disappear. Death rarely results, but when it does, it is most often from respiratory failure in children. Clearly, medical help and a dose of antivenin should be sought at once.

Many years ago, a young graduate student in biology told me his plan to use the black widow to ensure his future. Having read that black widow venom was difficult to get and valuable for research, he had devised (he said) a scheme that would catapult him to wealth and glory within a year. He was renting a small house, the basement of which he outfitted with glass tterrariums filled with black widows, which he strove to keep well-fed and happy.

Soon his little village was humming with weavers tending their egg sacs. Soon (he said) his slave labor factory would be churning out venom, and his buyers would be churning out money.

Alas, it was not to be. Returning from vacation, he discovered there had been a mass escape. In nature there is a staggering mortality rate among newly hatched spiderlings, thanks to birds, insects, and other spiders. But there in his protective laboratory conditions, save for periodic acts of cannibalism, the babies boomed. The would-be emperor of venom was faced with a nightmarish maze of webs and legs. Every surface pulsed with movement.

The modern-day Frankenstein experiment had veered beyond his control, proving yet again the adage that it's not wise to mess with Mother Nature. The grad student did (he said) what any red-blooded American boy would do. He ran upstairs, packed his belongings and moved.

The good news though, is that when it comes to biting humans, the shy black widow would rather not. She's a timid, nonaggressive homebody, really, who will likely try to retreat or play dead rather than bite. She will, however, bite in self-defense.

For the black widow, home is where her web is, usually in dark crannies on or near the ground. Unfortunately some of those places include human habitations like garages, storage sheds, basements, stables, and outhouses. An accidental brush or touch of the lady in her web may result in a bite. (Needless to say, the tender areas exposed in outhouses lead to especially unpleasant bites.) Willis J. Gertsch, in American Spiders, says, "In arid parts of Arizona almost every crevice in the soil harbors a black widow, and their nests are often found in cholla cacti and agave plants."

All spiders produce silk, but not all spin webs. The widow, while lacking the architectural artistry of some species, weaves a tangled web. Her silken snare is tough and elastic enough to entangle and trap the hapless insects whose misfortune it is to blunder into it. As vibrations (BELOW AND RIGHT) Despite its sinister reputation, a threatened black widow's first impulse is to run and hide.

To resonate through her web, she rushes from her hiding place to truss, paralyze, and eventually dispatch her victim.

Having probed the lady's dark side, it seems only fair to remind fellow arachnophobes of the service she provides. Thanks to her and her eightlegged kin, millions upon millions of crop-munching insects are destroyed. Without spiders our picnics would be even more overrun with uninvited ants. And despite the black widow's large numbers and wide distribution, documented bites are amazingly rare. At least this spider's stunning red hourglass marking and ebony potbellied shape make her readily recognizable. (Large females may measure half an inch in length, the males a third or less of that.) I suspect that even the gentlest and most harmless of spiders will never be warmly embraced by mankind. They have too many legs. They skitter about and startle us. Magnified, they look like malevolent, multieyed, bloodsucking aliens. The black widow's toxic qualities render her unfit for close companionship with humans, and control precautions are advisable.

She's a voracious huntress with a diabolical love life. She's a weaver. She's a recluse. She may be a femme fatale, but she's no merry widow.