Only one local species, the Black Widow, or ‘button spider’, Latrodectus mactans indistinctus, is known to be potentially lethal. The poison is neurotoxic, with the possibility of the victim dying of respiratory failure of heart failure or both. Less than 5 per cent of untreated bites by this spider may result in death. Young children and elderly people with heart or respiratory ailments are particularly at risk.
Most accidents occur when people lift objects or plants harbouring the spiders. If the spider is hurt in the process, it will bite in self-defence. When molested in their webs, they often sham death, rolling up into a ball. If picked up (while shamming death), they will bite. To avoid being bitten, the same precautions as with scorpions should be taken.