Words and pictures by Paul Donovan.
Eina How to avoid (and treat) spider and scorpion bites & stings.
Paul Donovan, a zoologist living in Botswana, has encountered a number of off-road travellers who’ve been bitten by spiders over the past few months (particularly when collecting firewood). Read on for his advice on how best to deal with these creepy crawlies.
A The bush presents us with many hazards, but often the emphasis is placed on the dangers posed by large animals such as elephants, rhinos and lions, when in fact it’s the little creatures which can cause us more harm as they’re often ignored or overlooked. One such group are the arachnids – spiders and scorpions. Spiders and scorpions occur in a great number of habitats, in both natural and manmade environments. A spider or scorpion will be just at home beneath a rock or log as it would be setting up house in a pair of boots you left outside to air overnight.
Although it will never be possible to avoid all interactions with spiders and scorpions, with some forethought it is possible to reduce the chances of being bitten or stung. The following advice is intended to help you to avoid being bitten or stung, or to help you to know what to do – and not to do – if you aren’t so lucky.
With the exception of one family of spiders (Uloboridae) all 35 000 known species of spiders are venomous with various degrees of potency. Spider venom is neurotoxic in composition; in other words it causes paralysis. Interestingly, at species level, it has been shown to affect different classes of animals in different ways. For example laboratory animals such as mice, rats and rabbits, as well as dogs and goats, appear to be resilient to spider venom, while livestock such as cattle are extremely sensitive to it.
Don’t labour under the illusion that the bigger the spider, the more dangerous it is. Although a big Baboon spider is capable of inflicting a very painful bite, primarily because of its large knitting needle-like fangs, it’s the smaller spiders we need to be aware of – they can pack a venom punch on par with some snakes. Southern Africa is home to a number of arachnids whose bites can cause medical problems. These include the Violin spider (Loxosceles spinulosa), Sac spider (Chiracanthium lawrencei), Brown button or Black widow spider (Latrodectus mactans), Black button spider (Latrodectus renivulvatus) and the False button spider (Theridion).
Of the 1 500 known species of scorpions (making up 13 extant families), approximately 25 or so are considered to pose a medical threat to humans; in other words they’ve been implicated in human deaths. Unfortunately identifying these 25 is difficult for the layperson but as a broad rule of thumb (there are exceptions), the following guide can be used: thin claws and fat tail means dangerous, while fat claws and thin tail means less dangerous. The most dangerous species belong to the large family Buthidae but unlike spiders where it’s the small ones you have to watch out for, with scorpions it’s the big ones we need to be wary of.
The likes of the Granulated scorpion (Parabuthus granulatus), Transvaal Fattail (Parabuthus transvaalicus), and the Mozambique Fattail (Parabuthus mossambicensis) are all large, powerful species capable of delivering a virulent venom. I had a friend who was stung twice on the foot by a Transvaal Fattail – he spent five days in hospital, two of them in intensive care.
Although spider bites and scorpion stings occur throughout the year, they are generally more common during the summer months when both species are at their most active. Thus, bites and stings gradually taper off during autumn and winter when many species undertake a period of hibernation; then they pick up again the following spring. Avoid being bitten / stung With a bit of common sense and judicious care, the risk of being stung or bitten can be greatly reduced. More than anything else, you need to be observant, and understand that spiders aren’t fussy about where they make their home.