Dispelling the aura of danger around spiders

I keep telling everybody — spiders aren’t as scary/dangerous as you think. Now I have a paper that quantifies the risk of deadly spider venom. It’s low.

• The increasing popularity of pet arachnids urges some governments to take protective steps to prevent serious envenomations.

• A literature review was carried out to assess which arachnids can be classified as potentially dangerous.

• About 0.5% of all spider and 23% of all scorpion species were classified as potentially dangerous.

• Even envenomations from the most dangerous arachnids have a low percentage of serious or even fatal consequences.

• We conclude that the public threat from pet arachnid envenomations has been overrated.

Here’s the list of potentially dangerous genera.

Note that the list errs strongly on the side of caution. It lists Eratigena, the hobo spider, but says in the text that “there is not a single verified bite that confirms E.agrestis or other members of this genus as dangerous to humans”. Latrodectus, black widow spiders, do have a real record — 23,000 incidents reported over 8 years — but less than half of those cases involved envenomation, and only about 1% exhibited severe effects, and there were 0 deaths. The Parasteatoda and Steatoda species I work on are only briefly mentioned and dismissed because their effects are much weaker than those of Latrodectus.

I’ve also never encountered any of the spiders they list, and I’ve been looking. I guess if I lived in Malaysia or Brazil I’d experience more of the thrill of danger, but here in Minnesota we’ve got a non-existent concern, and even in those tropical countries it’s a relatively minor worry.

(Of course I learned about this paper from Gwen Pearson. It’ll be useful if anyone at the university expresses concern about the hundreds of spiders currently in my lab.)


  1. davidc1 says

    But ,but ,i am certain some people who were scared witless of spiders must have been scared to death of them ,i know you will blame their deaths on a weak heart.

  2. chrislawson says

    Even with genuinely deadly spiders like the Sydney funnel web, there has been only 1 death since the development of antivenom in 1981.

  3. dorght says

    I had a discussion once with my father about “spider bites”. Every unexplained swollen bump that wasn’t a mosquito bite he declared a spider bite. So I asked him how he knew it was a spider that bit him. He said it looked like all the other spider bites he got. The circular logic was unassailable.

  4. davidc1 says

    I think you are all missing the point ,disliking spiders is a phobia ,the suffers know the vast majority of the bast, i mean harmless spiders can’t hurt them .
    My late mother used to be scared stiff of thunder and lightning ,even when i told her lightning was just a couple of million volts seeking a passage to earth ,she still used to be scared of it .

  5. npsimons says

    Meanwhile, you can lose hands, feet and part of your face from being licked by a dog, even your dog:



    And cat bites and scratches are well-known to be dangerous. No, Karen, I won’t let your dog “kiss” me, I don’t care if it hurts their feelings.

  6. says

    I live in Malaysia and we have a resident wolf spider lurking behind the bathroom toilet. No worries though I’m originally from Sydney and after finding a funnel-web spider between the sheets one night very few 8 legged beasties faze me.

  7. unclefrogy says

    the thing about spiders is that they do not try to hide the fact that they live by killing and eating others. We prefer our carnivorous animals friends to not be so openly murderous and be our pals and plush beasts and think of us a benefactors. Those that are the hardest to befriend are liked the least. Cats are prized though brutal hunters and dogs are our best friends and wolfs are despised

  8. Paul Ripke says

    Ha! “Illawarra”. I grew up in the Illawarra, and have literally seen hundreds of funnel web spiders, without having to go look for them, filling all the corners and nooks and crannies in every shed. I think I squashed one once putting on a boot without checking first, and we may have lost a cat to a spider bite, hard to tell – although we’d also lost cats to possums, paralysis ticks, snakes and bush fires.

    Growing up, I always thought that our trapdoor spiders were rather cute – their meticulous well shaped round doors always impressed me.

  9. DanDare says

    Not scared of dying due to spider bite. Horrified of being bitten just the same. When I first come apon a fist sized spider my guts tighten and my spine shrinks and my whole body flinches. No thought involved. No reasoning involved. I have developed a protocol over the years. If I spot a large spider in the house I will capture it and move it outside. However any spider that catches me by surprise is unthinkingly squished.

  10. says

    No need to go to another country. Plenty of Latrodectus mactans here in northern Virginia. Look in enough places where spiders might make webs, and eventually you’ll find one that doesn’t have any attempt at symmetry or apparent logic at all. Likely a black widow web. They’re a mess. “Tickle” the web just right, and they’ll come zipping out of their hidey-holes to check their catch.
    Reading back, I don’t mean like a dusty, dirty, matted mass of old abandoned webbing, I mean a widow web looks like a bunch of random, interconnected straight line segments when shiny and new. It’s a wonder they catch anything.