This thin-legged wolf spider is holding her egg sac in her spinnerets. She did not bite anyone, and probably never would. Photo by Dana Wilde
So I’m looking through a Facebook page about insects and spiders. Creepy, I know, but amazing pictures show up surprisingly often in these places.
Anyway, I spot a nice photo of a wolf spider, and underneath it is a long thread of comments. Usually it’s better for your mental health not to look at the comments. But sometimes spider posts are seeking an identification, and sometimes I’m confident enough to help. So I skim down the thread. In this one, someone asks the almost inevitable question: Does this spider bite?
Some commenters unhesitatingly answer yes. Others say no. Others recommend killing the spider before it can bite you. As usual, somebody brings up the notorious brown recluse spiders. On this particular Maine-based thread, one person says something like: “I’m finding more and more people are seeing brown recluse spiders in Maine.”
Among a lot of misguided comments, this one really stands out. I start thinking, maybe I need to try, once again, to set the record straight on spider bites with facts from the actual world of arachnology. So here goes.
BITES
Spiders hardly ever bite humans. Most spiders’ jaws are not strong enough to break human skin. Almost all spiders’ first line of defense against huge dangerous beings like humans is to run away; almost no spiders make defensive attacks.
Spiders do not drink human blood or eat human flesh. If you’ve got an itchy welt on your arm, it was pretty surely not inflicted by a spider. Mosquitoes, deer flies, black flies, horseflies, bedbugs, fleas, gnats, ants, ticks, or any number of other mini-monsters who do want to eat you are far more likely to be the culprit.
Sometimes, a cornered spider with no option to run away might try to bite you. Among the spiders in Maine whose jaws are strong enough to break your skin are some wolf spiders, some jumping spiders, some grass spiders and sac spiders. In the unlikely event that one of them did try to bite you, you may not even feel it and might never know it happened. If your system has the right allergic delicacy to a spider’s venom, you might get a swelling. Sac spiders have a reputation for being able to give you a welt, but the fact is, there’s hardly any documented evidence of it.
No spiders who live in Maine are capable of fatally biting humans.
BROWN RECLUSE SPIDERS
Brown recluse spiders do not live in Maine. Their range is middle-south continental U.S., north to about mid-Illinois. They are almost never seen here. The last time a brown recluse spider was verified in Maine was in the 1980s. Maine’s foremost spider expert, Daniel Jennings, investigated the finding and determined the brown recluse spider pair were stowaways in a car that had recently driven from Oklahoma.
Brown recluses do have a bite medically significant to humans. But they do not seek out and bite people; they bite when they feel threatened and can’t run away. When they do bite humans, the result in almost all cases is at worst an itching welt. In a small percentage of cases, the welt may persist and require medical attention. In less than 1% of brown recluse bites, a severe reaction may develop, including damage to blood cells, renal failure, even death. But this is extremely rare.
The likelihood of seeing a brown recluse spider, let alone getting bitten by one in Maine is practically zero.
It’s hard to tell for sure, but this spider appeared to be a bronze jumper (Eris militaris). Photo by Dana Wilde
BLACK WIDOW SPIDERS
There are several species of widow spiders with medically significant bites, but none of them live in Maine. Their range runs farther north than the brown recluses, and every so often a widow spider who stowed away in a car or freight is reported here. A study made by Dr. Jennings in the late 1980s reported that while it’s not impossible for widow spiders to live here in Maine, it’s extremely unlikely because of the difficulty of their finding conditions warm enough to survive winter. If winters keep getting milder, this could change, of course. But for now, it is pretty certain that black widow spiders are not established here.
Widow spider bites, like brown recluse bites, are fatal in less than 1% of bites on humans. In fact, widow spiders are notoriously shy spiders who tend to run away and hide on the least provocation, like their cousin the common house spider which is seen practically ubiquitously in Maine and elsewhere. Only one black widow bite has ever been reported in Maine, and even in that case the spider is believed by investigators to have been misidentified.
SPIDERS ARE NOT INSECTS
Spiders are arachnids, not insects. Spiders have two body parts; insects have three. Spiders do not have stingers, they do not have wings, and they do not have antennae. Spiders are not scavengers; almost all of them eat only meat they catch and kill themselves. As such, they are good for your garden and house plants. And if you ask me, spiders are a lot smarter than most insects.
WHY ARE THERE SO MANY RUMORS ABOUT DANGEROUS SPIDERS?
In the U.S., few people had even heard of brown recluse spiders before World War II. Around then some researchers got wind of spider bites in the South causing reactions like those of a spider in South America. They investigated, found the culprit was a cousin of the Chilean recluse spider, and along the way noted that in a few cases, people had died. In the 1950s, magazines and newspapers got hold of the research and played up the fatalities — even though there were hardly any.
News media built on these stories, so prevalently that people started thinking there was a recluse or widow spider around every corner. The medical community, seeking to cover all the bases, started including symptoms of bites in medical manuals. Doctors began diagnosing welts and swellings as spider bites even when no spider had been seen, which, as far as anyone can tell, was usually.
The arachnologists knew all along the spider bite lore was wildly exaggerated, but had little success pushing back against stories and resulting rumors that played on people’s natural fears. A study in Italy last year of media reports about spiders found that 70% of the reports contained errors; 32% were sensationalistic; and almost none consulted an expert.
Then we have social media, where completely false information is confidently passed along as factual. I did not engage the discussion, but I’m pretty sure the guy who was “seeing more and more reports of brown recluse spiders” in Maine was speaking somewhere south of the truth. Whether deliberately or not, I don’t know.
Don’t kill your spiders. Even though they look monstrous, they’re actually your allies in your garden and your battle against the little bastards who do try to eat you.
Dana Wilde lives in Troy. You can contact him at naturalist1@dwildepress.net. His book “A Backyard Book of Spiders in Maine” is available from North Country Press. Backyard Naturalist appears the second and fourth Thursdays each month.
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