Five poisonous spiders are found on the continent of Africa, primarily in the southern region. Although most spiders avoid human contact, they will bite in self-defense if touched or squeezed. Spiders produce a venom to kill their prey, but only a few produce venom that is harmful to humans.
Button spiders (Latrodectrus), elsewhere known as widow spiders, are found in southern Africa. Females may may have red or white bands or a red hourglass on a rounded abdomen. Males are smaller, with red or white bands. Brown button spiders are cream, gray or brown with red to orange hourglass markings. The spiders build webs in bushes or under debris. Their neurotoxic venom produces a painful bite that may be accompanied by systemic reactions of sweating, cramps and muscle weakness. Brown button spiders produce a less painful bite, with localized pain and burning that may spread to surrounding tissue and lymph nodes. Symptoms clear within a day or two.
The baboon spider (Theraphosidae), known as a tarantula outside of Africa, gets its name from leg segments that resemble baboon fingers. These large, nocturnal spiders grow up to 3 1/2 inches long. They live in burrows beneath stones, where they wait for prey to approach. Neurotoxic venom is their defense against predators; a painful bite fron a baboon spider results in vomiting, difficulty walking and shock. Baboon spiders are sought as pets throughout the world. They are a commercially threatened species in Africa, and cannot be collected, transported or kept without a permit.
Sac spiders (Cheiracanthium) are pale tan, yellow or yellowish-green with bodies about 1/2 inch long. The spiders hunt at night and weave a protective silk sac under bark or stones to rest in during the day. They are somewhat reclusive and slightly aggressive. Sac spiders produce a cytotoxic venom that kills cells and produces blistering at the site with localized swelling and itching. The bites are not life-threatening.
Violin spiders (Loxosceles) are reddish-brown with a violin-shaped marking on the thorax. In the United States, the species is called the brown recluse spider. This nocturnal species sleeps in webs under logs or rocks during the day. They are shy creatures that will bite if disturbed. They produce cytotoxic venom that causes blistering at the site with some breakdown of tissue. Treatment is aimed at prevention of secondary infection.
Six-Eyed Sand Spider
The six-eyed sand spider (Sicarius), a medium-sized spider in southern Africa, is reddish-brown or yellow with no distinguishing markings and a body length of about 1/2 inch. The creatures bury themselves in the sand to await their prey. This spider will bite if disturbed, producing a cytotoxic venom that destroys tissue around the site and throughout the body causing internal bleeding. This is the most venomous spider in southern Africa. Although there is no anti-venom available, no human deaths have been recorded.
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