  Although spiders in general produce venom with which to paralyze their prey, only a very few have fangs of sufficient length or power to There are two poisons present in spider venom: a toxin which cause local symptoms, and a toxalbumin producing general symptoms. In those spiders whose bites produce systematic disturbances it is believed that the latter poison predominates. Where black widows liveBlack widows spin their webs in crevices between rocks, under logs or overhanging banks, in abandoned rodent holes, and in rock and wood piles. Indoors they are most frequently encountered in dark corners of garages, basements, and stables. Underside of black widow spider showing characteristic red “hourglass” mark on the abdomen by which this species may be recognized. A favorite and especially dangerous location in which a black widow establishes her home is beneath the seat of a pit toilet. Such a location is ideal for the spider because it is dark, is not usually disturbed, and insects, especially flies, upon which the spiders feed, are abundant. Humans using the toilet, unaware of the presence of the spider, arouse her by breaking or agitating her web, and offer especially tender and susceptible portions of their anatomies for her bite. Pit toilets in warm climates should always be built with hinged seats which should be raised and inspected frequently. As a further precaution, the underside of the seats should be treated with creosote, an effective repellent. Although the majority of people now recognize the black widow, some do not, hence they kill all dark-colored spiders on general principles. This is neither necessary nor desirable. The female black widow is a medium-sized, glossy black, solitary spider with a globular abdomen spectacularly marked on the underside with a bright red spot roughly the shape of an hourglass. The normal position of the spider is hanging upside down in her web so that the “hourglass” is plainly visible if she is below the level of the eye. Her overall length is 1 to 1¼ inches. The males are much smaller and, like the immature females, are grey in color and variously striped and spotted. Adult females spin egg cocoons during the warm season; each cocoon contains approximately 300 to 500 eggs which hatch in about 30 days. As many as nine broods per year have been recorded. The young grow fast but do not mature until the following spring or summer. Black widow bitesAlthough black widows ferociously pounce upon insects or other spiders much larger than themselves which become entangled in their webs, they are by nature retiring and bite humans only when restrained from escape by contact with the body of man. The fangs, which are about one-fiftieth of an inch in length, serve to inject from two large glands the venom which is reported to be much more virulent per unit than that of the rattlesnake. There is some pain and swelling at the site of the bite. The pain spreads throughout the body, centering at the extremities, which become cramped, and over the abdomen, where the muscles become rigid. There is nausea and vomiting, difficulty in breathing, dizziness, ringing in the ears, and headache. Blood pressure is raised, eye pupils are dilated and the reflexes are overactive. Medical records, according to Bogen Treatment of black widow bitesSince the venom of the black widow, among other properties, appears to affect the nervous system, its effect is almost instantaneous, and most first-aid measures are of little value. Stahnke has found that the iced-water treatment (as described in detail in the scorpion section of this booklet) is beneficial. The points of puncture should be treated with iodine, the patient kept as quiet as possible, and an ice pack applied or the part submerged in iced-water, and a physician summoned immediately. Baerg Internal use of alcohol is dangerous, and a person bitten when intoxicated would have much less chance of recovery. Professional treatment consists mostly in the use of opiates, hydrotherapy, and similar measures to alleviate the acute pain. Of more than 75 different remedies used, three seem to be outstanding as palliatives: spinal puncture, intravenous injections of Epsom salts, and intramuscular administration of convalescent serum when given within 8 hours. Dr. Charles Barton, of Los Angeles, recommends intramuscular or intravenous injection of calcium gluconate, 10 cc. in a 10 per cent solution. The patient should be encouraged to drink as much water as he will. He usually leaves the hospital on the fourth day. Recent experiments with an injection of neostigmine followed by one of atropine have had encouraging results, and the use of ACTH in several cases has had spectacular results, according to Readers’ Digest (Nov. 1951, p. 45). Control of black widowsBecause of their wide distribution and secretive habits, black widows are difficult to control. Basements, outbuildings, and garages should be cleaned frequently, and black widow webs and eggs destroyed. If accessible, the spider may be dislodged from her web with a broom, and smashed. The use of a blowtorch, where there is no fire hazard, is effective for both spiders and egg cocoons. Insect sprays, in general, are ineffectual. |
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