Everything you thought you knew about Brown Recluse Spiders is wrong. There is now a book,The Brown Recluse Spider, to set you straight. This is my review of that book.

His name was Bob. I was a kid, he was an adult that all the other adults seemed to think was cool. He used to have a job launching nuclear missiles for the Air Force, but then later got a job as a Hippie. He, another person or two, and I were sitting on a rock pile out in the woods, checking out the patch of marijuana planted, mysteriously, on the neighbor’s property. The neighbor was the head of the local John Birch Society. Whoever planted the patch of pot figured it would be better found, if ever found by the cops, on his property than on the property occupied by the hippies.

Somebody moved a rock. Bob said, “Oh, look, a Brown Recluse spider. They are deadly, but they hardly ever bite.”

I watched the Brown Recluse spider very carefully for a while and memorized it. I found many more over that summer, and in subsequent years. I became very good at identifying them.

This is what it looked like:

The rock pile harboring the “Brown Recluse” was many hundreds of miles away from the natural range of the Brown Recluse. And of course it wasn’t a Brown Recluse spider. Brown Recluse have been known to take up residence in buildings very far away from their home range, but very rarely. They are not found out in the wild outside of their natural range very often. I think Bob said something about running into these things all the time at the secret nuclear missile base, which was secretly hidden in Wyoming. There are no Brown Recluse spiders in Wyoming, either.

I’m making Bob sound like some kind of idiot. He was not, he was a very smart guy. But he had this wrong and so does everybody else on the planet, it seems.

A study was done about ten years ago to see how bad people were at identifying Brown Recluse spiders. People, focusing on people who should know or claimed to know, were asked to send in their spiders. Brown Recluse spiders were submitted from 49 of the US states and from Canada. They exist, however, in only 17 states and not at all in Canada. There is a spider that lives in California, a very common house spider that had never been properly studied. It does look a bit like a Brown Recluse. So many of those were sent in (California is NOT one of the 17 states Brown Recluse spiders live in) that spider experts were able to use the collection of those spiders, not Brown Recluse but some other species, to do the first major study of its anatomy.

Most of the things people mistake for Brown Recluse spiders are spiders that don’t look much like a Brown Recluse, like the wolf spider depicted above. Many of the submissions from the aforementioned study, and many of the “Brown Recluse” routinely submitted to spider experts by concerned citizens, are not even spiders. There are a few spiders that look like them, but really, it is not hard to learn the difference between the Brown Recluse and its close relatives and all other spiders. But to do so you need some expert training, and that can be attained, if you are attentive, with Richard Vetter‘s new book, The Brown Recluse Spider.

You have probably gotten the email at some point in time. Brown Recluse Spider Season is starting. They are very dangerous. They can kill you. Be afraid, be very afraid. And let’s show you some picture of children with giant patches of rotting and missing body parts or holes in their arms because they were bit by Brown Recluse Spiders, etc.

Vetter’s book is full of information on the Brown Recluse. Vetter is careful to define terms and to not speak over the heads of the average person who is not a spider expert, but at the same time, the work promises to become the standing monograph on this type of spider. It is authoritative and comprehensive where prior study allows, and as such, also points out where there may be excellent research opportunities for up and coming scientists.

I was interested to learn that the majority of behavioral and physiological work done with spiders is done with captive beasts. I believe that is generally the case with invertebrates. But the conditions of captive life dramatically alter key life history variables. More field study needs to be done of spiders, but the difficulties would be significant. It would probably bad for your back and knees. But as an experienced archaeologist, I have no sympathy. Get out there and start collecting field data, you guyz!

The Brown Recluse is one of many related species in the same genus, and the larger family of these spiders is found in both the old and new world. The taxonomy has an interesting and elaborate history, with much renaming and shifting around of phylogenetic position.

Brown Recluse eat mainly invertebrates. They don’t build much in the way of webs, and don’t really use webs to capture prey. They either hang around waiting for something to come along, then possibly attack it, or prowl.

The dispersal patterns of Brown Recluse are very interesting. They may become very common locally, but not found nearby that locality. And by locality, I mean a single outbuilding on a farm, where they are common, not to be found in other outbuildings. That is a very small scale concentration of population. Studies looking at spider dispersal have found that some species of spiders disperse great distances, including those that use a strand of web to fly as much as thousands of feet into the air, presumably traveling great distances. Brown Recluse don’t do that.

The native range of the Brown Recluse and closely related species includes a small part of California, Arizona and New Mexico, all of Texas, Oklahoma, Kansas, southern Illinois and Indiana, most of Kentucky and Tennessee, Western Georgia, and all the areas I just circumscribed with a circle of states such as Mississippi, Alabama, Louisiana, Arkansas and Missouri. The Brown Recluse itself, however, Loxosceles reclusa, is mainly restricted to Texas north to southern Illinois and east to Kentucky and Tennessee. Oh, and a tiny bit of the Florida Panhandle.

Here is how you pronounce the latin binomial. Say “Isosceles” like in the triangle. Not say it neat, without “ice,” and lock it down with a “Lox” in front. I imagine scholars differ on REEclusa vs. RAYclusa.

According to Vetter, “Outside of its native range, the brown recluse spider is rarely found….In comparison, to find forty buildings populated by brown recluse spiders in Kansas or Missouri, one would have to walk down just one residential street.”

Vetter makes two very important points about this spider that you need to understand.

First, many, many Brown Recluse spider bites, serious afflictions that are treated as spider bites, are not Brown Recluse spider bites. The misdiagnosis is generally done by a professional medical worker, and often in conduction with someone identifying a spider as a Brown Recluse incorrectly. There are other medical afflictions, including other bites but also things that are not even invertebrate caused, that are mistaken for bites of these shy spiders. That can lead to serious negative consequences for the patient. Also, for any invertebrates living in the area along with any one who breaths in the anti spider gas and juices that may be liberally spread around to kill a spider that does not exist locally.

The second is that we actually know too little about the physiology of the Brown Recluse spider bite, and need to know more. Vetter has a whole chapter on this.

The bottom line is that Brown Recluse spiders are extremely common in some areas but hardly ever bite anyone, and totally absent from vast areas where they are blamed, incorrectly, for the occasional lesion.

There are definitely dangerous spiders, and the Brown Recluse is one of them. But the human reaction to spiders in general, and even to the species that do have a nasty bite, is almost always overblown, as least in Western culture.

I believe that the vast majority of “spider bites” people get are not spider bites. Here’s why. The ideal mosquito bite involves the mosquito getting her proboscis deep into your skin, hitting a blood vessel, and withdrawing a good meal of blood. That takes a long time and is often not successful. The unsuccessful “bites” may leave a mark and be itchy, and that is what most people think of as a mosquito bite. But a successful bite will generally leave a welt, large, red, painful, itchy, and that stays around for a few days. When people get those, they call them spider bites. Why? Because most people simply don’t know what a real mosquito bite is, and think spiders bite them all the time.

That is why The Brown Recluse Spider by Vetter is a great book. It is clear, well written, authoritative, and you can’t help but be much better informed by reading it. If you live in Brown Recluse land (see map above) you need this book now, just go get it. If you don’t, and you are into inverts, science, or anything related, you’d enjoy it as well. Great book, highly recommended.

How do I get rid of the spiders???

We had a wet spring and summer in Minnesotan. This meant that insects did quite well at the start of the season. Spiders mainly eat insects (and each other, of course) so that meant that the first generation of spiders had a higher success rate than usual. After that, the compound interest effect kicked in so now, by the end of the season, it is said that many homes in the Twin Cities and greater Minnesota are loaded with the tiny eight-legged creatures.

Is it bad to have so many spiders? What if a spider bites me???

Keep in mind that the reason there are so many spiders in your house is that

there were a lot of insects for these spiders to eat. So, for every spider you see now, there were a whole bunch of insects that got eaten. So, one could say that it is a good thing that there are a lot of spiders in your house!

Spiders don’t bite people very often. There is a belief that spiders come into your bed and bite you during the night. People who wake up with large red welts that itch or hurt may think that they were bitten by a spider. The rule of thumb, it seems, is this: A small welt that itches for a while then goes away was a mosquito, and a larger welt that lasts a long time is a spider. This is not true. Most likely both are mosquito bites, but the smaller welt is from an unsuccessful mosquito bite where you chased the mosquito away or mushed it before it got finished with you, and the larger welt is from when you were sleeping and a mosquito had a nice, full, complete, slow, delicious blood meal at your expense. A spider did not sneak into your bed and bite you. They don’t do that. (I quickly add that your large uncomfortable welt could have been something else besides a mosquito, but not likely a spider).

See Also: The Truth about the Brown Recluse Spider

People just say that it was a spider bite because they are more creeped out by spiders than they are by mosquitoes, so the mosquitoes get blamed for the smaller bites and the spiders get blamed for the bigger bites.

One downside of having a lot of spiders is, of course, having a lot of spider webs, also known as “cobwebs.” (Word Origin: the word “cob” comes from an old word for spider dating to when Dutch and English overlapped more, which is why it sounds Dutch: Coppe.)

OK, so how to get rid of spiders

Most sources will tell you to start by sealing off all the cracks in basement walls and window casings. Fine, go ahead. It might be, though, that those cracks are where the spiders might hang out and thus be invisible to you, which is the same as getting rid of them, right? In any event, whether or not you can do this depends on where you live. For most of my life before moving to the Midwest, I lived in houses that were between 100 and 200 years old. Forget about sealing cracks in places like that. But if you live in a modern home it might be possible. So get out the caulk and get sealing.

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Insecticides don’t work particularly well on spiders for two reasons: 1) they are not insects; and 2) many insecticides work on the principle that the insect drags its body across the surfaces you’ve wet down with the juice. Spiders keep their bodies up off the surfaces they are crawling on. But, getting rid of the insects will reduce your spider population because you are starving them out. Personally, I don’t like using insecticides. They are icky and smell bad and it amounts to spreading a poison around in your living space. So go spray some around if you want, but wait a week or two to invite me over, please!

A common piece of advice is to make sure your house has very little stuff, like boxes or storage containers or furniture or drapes etc. where spiders can hide behind. This advice amounts to telling you to get rid of all your stuff. So go ahead and do that and you’ll have fewer spiders. I don’t think you are doing to do that, though.

Another piece of advice is to cut down the bushes and trees near your house. Seems a bit extreme to me. It is a good idea to cut back plants that would shade a burglar who wants to spend some time breaking into a particular window or something. You could just get a dog, though. The dog will need to be fed, however, and the food will attract and nourish insects, then that will cause you to have more spiders. And, the dog will have fleas and you’ll get the occasional flea bite and blame the spiders, and then you will think you have more spiders than you do, which will produce the opposite effect we are going for here.

OK, ok, so all these methods and other methods you see on the internet don’t work, or have undesirable side effects. So what is the point? Is there nothing you can do? Of course there is, and I told you a major clue at the beginning of this blog post!

So, how do I get rid of the damn spiders, then, smartypants?

You can’t get rid of them but you can reduce their numbers. Here’s how: Get a vacuum cleaner and go all around your house in the spring, after the insects and spiders have started to become active (which depends on where you live) and vacuum up all those nooks and crannies using the wand attachment. Make sue you have a good vacuum and the bag is empty and all that so you have good suction. Vacuum the ceiling of your basement, all the corners, around the molding (don’t forget over the door frames) and behind furniture, under the couch cushions (including in the deeper often missed recess of the couches and overstuffed furniture). Turn the furniture over … all of it … and vacuum underneath. Don’t just reach under your dining room table: Get on your back like you were changing its oil and vacuum out every little nook and cranny up under there.

Obsessively, compulsively, suck up every bit of dust everywhere in your house, and that will get rid of 99% of the extant spider, insects, eggs, egg sacks, and even the food may various insects will eat. Well, not really. There are entire categories of insects or other creatures that are too small to see and that can’t really be vacuumed, that that you’ll probably miss, like the mites that live on your cat’s eyebrows. And your eyebrows. Nonetheless, if you give your house a very very thorough vacuuming and cleaning you’ll stop that first generation of spiders form doing well. The remaining spiders, or the ones that sneak into your house later on, will not have the head start they usually have, and as each generation grows and grows in number they will not achieve the large population they other would have.

Yes indeed. Compound interest works both ways!

One final piece of advice: Most people do not seem to realize that many biological phenomena occur in cycles spanning several years. Is that oak tree especailly annoying with its acorns this year? Well, they only do that every few years … for a reason … and you may not have noticed this. The mistake many make is to take the worst year and use that as their benchmark. The truth is that if you have a lot of spiders in your house all of the sudden, this does NOT mean that your house has made some sort of transformation from a house in which there are hardly any many spiders to one overrun by them and will thereafter be spider-house. No. Most likely you have experienced a simple natural cycle and if you do nothing, there will be fewer the next year. My advice …. to relax about the spiders but do a major hit on their numbers early in the year using the basic organic and safe technique of vacuuming everything up … will reduce the amplitude of those cycles so low-spider years will seem spider-free and high-spider years will be not as annoying. And it is all about the perception of spiders and not how many spiders there actually are. Because you can’t really get rid of them.

(If you’ve got kids, you could always teach them to catch and release the spiders, like they do HERE!)

Photo of spider by Greg Laden. Tule Block, Botswana

More about spiders: CLICK HERE

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