The venom toxicity of South Africa’s black widows has been studied extensively and is reportedly in the region of four times more powerful than that of the brown button spider. A bite may not be painful … initially. With time, pain will begin radiating up the limbs to the lymph glands and will have serious effects on blood pressure, causing profuse sweating, muscle cramps, stiffness of the stomach muscles, pain in the legs and weakness.
If bitten, a person must be hospitalized and vital functions monitored for up to 24 hours. The administration of antivenom is the only effective treatment for severe symptoms. If the bite victim is elderly or very young, the symptoms will appear to be far more severe.
Bites and venom aside, here’s what else you should know:
The spiders are considered to be of medium size, long-legged and with shiny, round abdomens. South Africa’s black widow (or black button) spider – Latrodectus indistinctus – lacks that distinctive hourglass shape on its abdomen, unlike its infamous cousin from North America. Instead, it’s South Africa’s less venomous brown button spiders (or brown widows) that display the red hourglass, which is probably why they’re often mistakenly viewed as the more dangerous of the two.
Where are you most likely to bump into them? For brown button spiders, look closer to home – garden furniture, window sills and other nooks and crannies of the house. But before you panic, here’s a little firsthand account to put your mind at ease. I once visited a house in South Africa’s Kalahari region where a brown button spider was to be found under almost every table and chair … and, just as an added bonus, one made an appearance every evening by hanging just next to the toilet seat. The owners had been living with these arachnid house guests for years and no one had ever been bitten, proof of just how reluctant these creatures are to bite.
Black widows, on the other hand, prefer to spend their time away from human habitation. They’re far more likely to be found under rocks and logs, in a very messy tangle of webs. When disturbed, they will retreat to the rear of the web, avoiding contact at all costs. They are not at all aggressive and bite as a last resort – when handled or accidentally crushed.
The males of both species are small and harmless to humans since their mouthparts are too tiny to pierce the skin.