Most spider bites won't kill you. Only an itsy-bitsy portion of the world's more than 43,000 known spider species pose a danger to humans, and fewer than 30 species have ever killed a human. Which bites have the best chance of making you bite the dust? What is the deadliest spider in the world? Britannica lists nine of the most lethal arachnids on the planet. Among them are the usual suspects, including the brown recluse and the black widow. But identifying the reigning king of spider bites is a bit tricky, because there are actually two spiders who can lay claim to the throne. Number 8 on Britannica's list is the Brazilian wandering spider, "considered to be the deadliest of all the world's spiders." However, number one on that same list is the Sydney funnel-web spider, which Australian Geographic describes as the undisputed title holder in the deadly arachnid rankings.
So what makes these two particular spiders so dangerous? Rather than having the arachnids perform a bite-off to see how many lives they can end within a specific time limit, it seems more sensible to discuss both the Brazilian wanderer and the Sydney funnel-web in more abstract terms. Live Science writes that Brazil is home to eight separate species of Brazilian wandering spider. Their venom contains a mix of different toxins that can cause burning pain, vertigo, blurred vision, an elevated or decreased heart rate, spikes or drops in blood pressure, and hypothermia. You definitely don't want one of these crawling on you.
Luckily for humans, Brazilian wanderers rarely go in for the kill. A 2008 study determined that only 2.3 percent of bites from Brazilian wanderers needed to be treated with antivenom because the spiders inject venom sparingly. They aren't being merciful, though. Arachnologist Jo-Anne Nina Sewlal explained:
"It is unlikely that the spider would inject all of its venom into you, as this venom is not only needed as a means of defense but to immobilize prey."
Because it takes time and energy to replenish venom, if the spider used its whole load on you, it would be vulnerable to would-be predators and unable to hunt the prey it wants. So unless you come across an especially hungry Brazilian wanderer, it probably won't bother to envenom you very much. Not because the spider is nice, but because you're just not worth it. Maybe the burning pain people feel when a Brazilian wanderer bites them is just the sting of rejection.
So how does that compare with the Sydney funnel-web spider? The deadliest of Australia's 35 species of funnel-web, the Sydney variety delivers a nasty neurotoxin which paralyses invertebrates but causes human neurons to fire continually. A bite might cause your heart to race and your blood pressure to rise and could kill you within 15 minutes.
In case that's not enough to send you into an arachnophobic frenzy, a funnel-web's fangs can puncture everything from toenails to mouse skulls, and these spiders are inclined to hide in your shoes or house when seeking shelter. Strangely enough, While the venom wreaks havoc on primates by virtue of an evolutionary accident, dogs, cats, and birds all have built up an immunity.
A total of 13 people have died at the fangs of the Sydney funnel-web. That body count might be even higher had experts not developed an antivenom in 1981. Unfortunately, keeping the supply stocked is a tall order. It takes roughly 70 milkings to acquire enough venom droplets to produce antivenom. Further complicating matters, a female's life span may stretch 20 years while males kick the bucket after about four years and aren't usually bred until they're two years old.
According to Ranger Mick from the Australian Reptile Park, there's at least one trick you can use to keep these spiders at bay. If Sydney funnel-webs think there's no place like your home, you should invest in chickens, which are apparently happy to eat up all the funnel-web spiders they can get.
And if you don't live in a place where you can keep chickens, well...there's always fire.
#Spiders #Arachnophobia
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