Poisonous spider

Cecil's Columns/Staff Reports
1

RE: your article on poisonous spiders.

I’m a biologist that happens to study spiders. I applaud your article for stating what arachnologists have said for years, namely that most bumps, red spots, etc. are likely NOT to be spider bites. In reality, there are more harmful biting insects than there are poisonous spiders. A few summers ago, I was collecting spiders at a field station when a fellow biology student visited a doctor about bad bite on her ear. Despite the fact that the black flies were vicious at that time, the doctor blamed a spider!

But a colleague of mine, a spider toxicologist, has an issue with one of your statements. I quote him here :

Fighting BS with BS:

“Of the handful of dangerous species, nearly all have venom that either kills you within a matter of hours or completely goes away within the same period.”

Sounds like another myth in the making …

If you wish to discuss this point, he can be contacted at www.spiderpharm.com. Chuck is one of the top men in spider toxins.

2

Please don’t rush off.

A well-educated, no nonsense poster like yourself would be quite welcome on the SDMB. :slight_smile:

3

Welcome to the Straight Dope Message Boards, Tenebrosus, we’re glad to have you with us. I think you’re referring to what we call a “Staff Report,” not written by Cecil Adams Himself but by Doug, an entomologist at University of California, who is not a spiderologist but does know whereof he speaks. I leave the discussion of your point to the experts, I just want you to be aware that Doug is well credentialed.

Since this is (presumably) a Staff Report, I’m moving it to the appropriate forum. And, it’s helpful to other readers if you provide a link to save search time. In this case, I assume it’s: Straight Dope Staff Report: My dad’s hospitalized with a big bump on his arm - could it be a spider bite?

This will, in fact, be on the front page on this coming Tuesday (Dec 27.) And, as I said before, welcome!

4

It’s a matter of faith among all the Northwesternites I know that we have brown recluse spiders. We find them all the time, typically hiding in cellars, attics, and wood piles. They’re generally smaller than wolf spiders (or what we call wolf spiders, are we wrong about that too?), with longer legs, and lots of little hairs. I don’t know that I’ve ever seen a “violin” shape on any of them, but I haven’t looked that close…

If these aren’t brown recluse, what are they?

5

I am not a spider expert. I’m not an entymologist. (I do know the difference between Pholcus phalangioides, which I call 'daddy long-legs, and the non-spiders of Phalangiidae, which I call ‘harvestmen’.)

I have heard that there are brown recluse spiders here (I live in Birch Bay), but I’m not convinced. My friend I bought my house from said there are ‘hobo spiders’ here, which he says are similar to the recluse. I have never knowingly seen one.

It really is The Kingdom Of The Spiders up here. When I lived in the Mojave Desert black widows were common, but they didn’t overrun everything. Here, it seems to be a never-ending battle to keep the daddy long-legs under marginal control. One must look carefully outside, lest one runs into an orb weaver’s web. ‘Wolf’ spiders are everywhere. Those cute little jumping spiders pop up frequently. (They have such cute faces!) And there are large-ish dark grey spiders (leg span about 50mm) with bumps on their backs. One of them made sort of a funnel-shaped web in the engine bay of my Triumph Herald. (Usually I see them under things, such as my trash bin.)

I found hobospider.org, but I haven’t had enough tea yet to enjoy it.
(I’ll get to the Staff Report later as well.)

6

And Doug says:

He also says:

My father was bitten on the back of his calf by a black widow. This caused an ‘ulcerated’ wound that took weeks to heal. (Dad hated black widow spiders and would not tolerate them in the house, garage or yard.)

7

As Johnny said, probably Hobo spiders (scroll down on that site to see pictures of both a male and female). They have a different back pattern than the Brown Recluse

8

Hello,

Though I am an arachnologist (and an entomologist, with a specialty in aquatic insects), I am not an expert in spider toxins. Chuck Kristensen (www.spiderpharm.org) and Greta Binford (http://www.lclark.edu/~binford/) are the only spider venom experts that I’m aware of.

Black widows are indeed common as dirt in west - two species occur. Lactrodectus mactans and the larger Lactrodectus hesperus. I find mostly* L. hesperus* in Reno, though I have seen a couple of L. mactans. But unless some recent evolutionary change occurred, *Lactrodectus * venom is a neurotoxin, while the brown recluse (Loxoceles reclusa) is a necrotic toxin. The hobo spider (Tegenaria agrestis) is a bit of an enigma, since they are presumably harmless in Europe (where they originated) but cause an ulcerated wound in approximately 50% of Americans (that number may have changed, since it’s been awhile since I’ve seen a professional presentation on Tegenaria agrestis). I saw a presentation by Greta at the International Society of Arachnologists in Chicago a few years ago, and recall that she found very few differences between the European samples and the American samples.

Your staff member, Doug, cites a very vocal member of our arachnology community, Rick Vetter. But I know that Rick and Chuck have disagreed before on some topics. In particular Chuck disagrees with Rick’s passionate insistence that the brown recluse is not in California, (and indeed, Loxoceles reclusa is not in California), but a Chilean relative, Loxoceles laeta, has been found in California. Chuck states it is just as bad, if not worse, than L. reclusa.

I prefer to trust Chuck and Greta, in large part because they are the experts in spider venoms, and Rick is not. But beyond that, it is really a battle of the experts.

I would also like to point out that reaction to spider venoms, like reaction to insect bites, is highly variable. Another member of our professional community, Dr. Susan Reichert, states that when bitten by a brown recluse, she gets no more than a red pimple like formation. Others have more severe symptoms. Chuck has mentioned that southerners tend to have less severe reactions than northerners, possibly due to the fact that the brown recluse is more common in the south. No one has done a medical study that I know of at this time.

9

Wow. Looking over some of the other posts, I wanted to clear up a few misconceptions.

I study fishing spiders, the genus Dolomedes (in the family Pisauridae currently) and the family Trechalidae. Wolf spiders (Lycosidae) is in the same evolutionary clade as Pisauridae and Trechalidae at the present time (these relationships may change as we gather more molecular data, one of my current studies). So with expertise, I can say that Wolfies vary considerably in size - the tiny Pirata (which live in similar habitats as one of my study species, Dolomedes triton) to considerably larger *Lycosa * species.

*Loxoceles * species (brown recluse) have six eyes, rather than the much more common eight eyes seen in other spiders. Though when people inquire whether the brown spider in their house is a brown recluse, and I ask them if it has six eyes, they say they don’t want to get that close to check :slight_smile:

Pholcidae, a common brown house spider, has a brown marking on its carapace that causes it to be mistaken for a brown recluse. Pholcids, however, are harmless. They are also often mistakened for daddy-long-legs (which are opilionids) because they also have very long, slender legs. Both are arachnids, but the Opilionids are not spiders.

10

Allow me simply to add that I hope that our new guest sticks around. It’s always nice to have really well-credentialed board members. :slight_smile:
I used to live in the northern Mojave Desert (growing up). Black widows were much too numerous for my taste. As I have found with most spiders, leaving any dark area unmolested was certain to result in the establishment of a web. I recall one crawling out from under the piano one day after I had dropped a piece of sheet music behind the piano. She was quite unhappy at having had her piece and quiet disturbed; I shared her feeling. :eek:

11

I have three personal experiences with spiders. First, about 9 years ago, I was bitten by a small spider (I saw it bite me), judging by the size and description, and from various pictures on the web I’m assuming it was a yellow sac spider, but I have no positive confirmation and IANA entomologist. The result was a pimple that lasted about 3 days. Second was my ex-wife, she was bitten on the foot by a brown recluse, we recovered the specimen (the corpse was still in her shoe) and this resulted in an open wound that took about 3 months to heal. We lived in the country at the time and, although we only saw a few in the house, there were quite a few living in and around our wood pile. The third was with a wolf spider, it was pretty big, about a 4 inch span across the legs and a good inch of a body. I know they are not poisonous, but they still pack a punch. She nailed me on the back of the hand and it hurt for a week, but no swelling or venomous (or secondary) reaction.

My question is not really about spiders though, it’s about “Daddy Long-Legs”. Summer before last (2004), I saw more DLL’s than I think I have ever seen in my life. They were everywhere, I would pitch about 12-15 of them out of my apartment when I got home from work every night. My girlfriend and I took our kids camping in Brown County state park and were overrun by them. There were between 30 and 80 on our tents at any given time (yes, we counted) and we could not shake them off, they just kept coming and we ended up abandoning the campsite. This was also the year of the 17 year cicada. Is there any connection between them (their cycles I mean)? Was there a large population elsewhere (I live in central Indiana)? Do they normaly swarm like that? Could we have pitched our tents over some sort of nest (they all appeared to be adults thought)? Are they really venomous but with tiny mouths so they cannot really bite or is that just an urban legend? I don’t remember seeing so many this last summer, but I do remember them being more distinctly marked than I had ever seen. Any thoughts?

12

I know for an absolute fact there was one single lonely brown recluse spider in Fresno CA back in September of 1983. It was so angst filled at being alone it bit mrAru on the leg behind his right knee, and was prompty swatted and taken to the ER. It couldn’t be saved - poor thing was DOA, but mrAru has the spiffiest crater on his leg now.

13

I for one welcome our new spider overlords…
Seriously, it seems that almost every time I or someone I know has small irrated red bumps that have sprung up seemingly out of nowhere they’re written off as spider bites. Nevermind that there are scores of irritants that our skin comes into contact with on a daily basis, our common misunderstandings would have us believe that we’re under constant attack by our little eight legged buddies. If we’re not swallowing them by the handful in our sleep, we’re being bitten unmercifully as well. I’ve even been told by more than one person that they have a series of bites along a part of their body that’s been caused by spiders copulating on them while they sleep.

There certainly is a great deal of rubbish believed about spiders, and I hope our new guest decides to stick around and help dismiss the more insane of them.

14

Great Staff Report, Doug. I just wanted to relay an anecdote that is relevant.

When I was stationed in Florida, my cutter went to drydock way down the St. Johns river. One night, one of the guys who works for me (we’ll call him Joe) ended up with a raised red mark on his cheek. Unable to explain it, he was taken to the Navy docs in Jacksonville. Without anything to go on, and the victim feigning ignorance as to how it got that way, it was diagnosed as, (you guessed it!) a Brown Recluse bite. As a result, he ended up getting his cheek opened up and packed with guaze twice daily for about a week. Boy, that must have been fun for him.

It was months later that I learned the truth. The night before the mark showed up, he was out drinking with some shipmates, when one of his buddies had way too much. As Joe was trying to help him back to the cutter, the drunk swung at Joe at hit him in the cheek. Hey, it happens. Not wanting to get his buddy in trouble, Joe played dumb and became the victim of the horrid Brown Recluse spider!

Joe really took one for his buddy with that whole episode.

15

It’s a myth. They are venomous, but not dangerous to humans. Mythbusters had one of the guys stick his arm into a container full of daddy long-legs. They didn’t want to bite him, as they aren’t very aggressive. He did finally get one to bite though.

16

I wish I had a dollar for every time someone repeats the Daddy-long-legs are the most poisonous spider in the world myth. I’d make more money that way than I would teaching college biology.

First, Daddy-long-legs (aka Harvestmen) in the US are members of Opiliones. Opilionids are arachnids (they have 8 legs) but are not spiders. You can tell the difference by counting the body parts. Opilionids have one body part - a fused head, thorax and abdomen. All spiders have two body parts - a fused head and thorax (cephalothorax) and abdomen. Sometimes, like in the case of theriidids (widow spiders are included in this family), the cephalothorax is much smaller than the abdomen. But spiders always have two body parts.

Second - almost all opilionids do not have venom glands. Some are detritovores (meaning they eat moldy, decaying stuff lying around). the ones that do have venom glands do not produce enough venom to harm humans. I recall that the show Myth Busters examined the venom that is produced by the few opilionids that produce it, and declared it to be harmless to humans. But I did not see the episode, and cannot vouch for their accuracy.

So where did the rumor come from? A colleague of mine, Bill Shear, though it was due to a confusion of common names. IN the US, Daddy-long-legs are harmless opilionids. In Australia, the daddy-long-legs is a spider. I do not recall if the Australian daddy-long-legs is poisonous to man. But in my opinion, there are more things that will kill you in Australia than anywhere else in the world (no actual study was done, but I’d lay bets on Australia anyway). In any case, the relatively undisputed deadliest spider in the world is Atrax, the Australian funnel web (or Sydney funnel web) spider. A close second is Phoneutria nigriventer, the Brazillian wandering spider or banana spider (so called because they are accidently shipped with bananas from South America).

17

In the U.S. a 'daddy long-legs is a harvestman. In the U.S. a ‘daddy long-legs’ is also a spider.

18

Your link is broken.

I know Wikipedia is not always the most accurate resource in the world but here is their article on Opiliones. It has a nice picture of the Harvestman on the top, this is the exact little critter we were overrun with (ok, not the exact one, but one of his little neices or nephews). The article also has a link to the wikipedia article on daddy-long-legs spiders as well. Per the smell the various sources say opiliones emit, I don’t particularly remember it or didn’t notice it. Either I wasn’t paying attention or (more likely) the smell of the cans of OFF we hosed our tent with masked it. For future reference, OFF has no effect on opiliones (Tenebrosus probably could have told us that if he had been in the woods with us, too late now though :smack: )

19

His link is also a .uk - United Kingdom. As I mentioned, Australians typically use the word daddy-long-legs to describe a spider. But in the US, Americans typically use the word daddy long legs to describe opilionids.

Pholcids, like the extremely Pholcus phalangoides, have very long, slender legs and may be called daddy long legs for that reason in the US by some folks. But most professionals, when asked about a daddy long legs someone found, is almost always given a opilionid. I can say in my ten years as the local arachnologist, the only daddy long legs that I have been given by locals were opilionids.

Wikipedia isn’t the most accurate site, however their short article on Dolomedes was written by me. Since only a handful of Dolomedes experts exist (most professionals study jumping spiders, wolf spiders, or the dangerous spiders like the black widow or brown recluse), I figured no one else would write one. I need to flesh it out more, but I have been busy with my own research (I study geographic variations of Dolomedes species in North America) and teaching. And for the record, I’m female. Judging by the last arachnology meeting I attended, I’d say about 1/3 - 1/2 of professional arachnologists are female. Some of them are very well known - including Susan Reichert (Agelenidae), Rosemary Gillespie (Tetragnatha and the Hawaiian Happy Face spider), and Maydianne Andrade (widow spiders, particularly the Australian red back spider).

20

On Daddy Long-Legs: there’s also Is a Daddy Long Legs the most poisonous spider? where SDSAB Dogster (neither a bug-ologist nor a spider-ologist, but with plenty of experience amongst critters found in junkyards) tackled this one.

Also note that there’s another thread based on this Staff Report, with speculation about what kinds of things might be misdiagnosed as “spider bites”?