Robert Gale Breene III
College of the Southwest
Carlsbad, New Mexico USA


How To Give A Spider A Bad Name

Below is a review of "Envenomation by a spider, Agelenopsis aperta (Family: Agelenidae) previously considered harmless. R. S. Vetter. 1998. Ann. Emerg. Med. 32: 739-741." Before getting to the paper, I believe a long overdue discussion of the terminology dealing with arachnid venom should be covered first.

Venomous: A meaningless term when used in connection to effects on humans, since all spiders, except for one of the 106 spider families (Uloboridae, the hackled orbweavers) and some members of another (Liphistiidae, segmented trapdoor spiders) and all scorpions have venom. What does this mean? It means they have venom, so what.

Envenomation: For the medically inclined folks, this seems to mean a clinically significant reaction by a human to the venom of a spider or something. It's another meaningless term often loosely applied.

Poisonous Venom: Nobody can decide what this really means. "Poisonous" implies some toxin that needs to be ingested to affect a human. I don't think there's many spider eaters out there, except for that South American tribe that apparently enjoys eating 200 dollar tarantulas on television, much to the despair of viewers sympathetic towards those poor damn things. Another worthless term.

Toxic Venom: I think we're getting closer to an accurate description here, but not by much. "Toxic" can mean a number of things to a wide range of people. It's not all that acceptable. The word "toxic" is from the Latin meaning poison (see above).

Potentially Harmful Venom: I don't like this term and neither does anyone else I know, but it's all we have. The definition of this phrase: A species possessing venom that has consistently been demonstrated to cause clinically significant damage to humans, either by neurotoxicity, or by causing the formation of necrotic lesions. This may not be the most accurate description, and may change, but it's the best we currently have.

Under this definition, no tarantula species has potentially harmful venom (despite what many Internet listserver participants believe) since bite reactions are anything but consistent, and the psychological effects of the few "reported" bites cannot be separated from real physiological ones.

In the US, this leaves three groups of spiders clearly meeting the definition. Loxosceles, the recluse spiders (although not all of the 13 species found so far in the US have had their venom tested), Latrodectus, the widow spiders (five species in the US), and the hobo spider, Tegenaria agrestis (Walckenaer). If the nitroglycerin patch treatment for recluse bites is as effective as some say it is, Loxosceles may need to be removed from the list of spiders with potentially harmful venom (and more than likely, the hobo spider as well).

Vetter's paper starts out claiming that it is the first report of clinically significant bites by this species, [Agelenopsis aperta (Gertsch), Agelenidae, the funnel weavers] and that it should be considered "a creature of occasional medical importance."

For evidence, Vetter presented two case reports. In the first, a large spider was brushed off the neck of a nine-year old boy while in school at 8 AM in Riverside, California. The spider was collected and later identified as A. aperta. A mark appeared on the boy's neck, which soon felt rigid and swelling of the pharynx appeared. This was followed by a headache. By 1 PM, the boy was taken to an urgent care facility. He had pain in the muscles and joints of the neck and shoulder and was given a tetanus shot, some antibiotics, a popular pain killer and was sent home. Before the boy left, the attending physician told the boy he had been bitten by a brown recluse spider.

At 7 PM, the "symptoms" had worsened and he was returned to the urgent care facility. The symptoms included general malaise, pallor, unsteadiness, heaviness in the legs, a bad headache and tightness in the throat.

Well, excuse me, but does anyone out there think this just might be a PANIC ATTACK! If I was nine (they tell me I was once, I don't really believe them) it wouldn't take me anywhere near six hours to begin panicking after an adult super authority figure just told me I'd been bitten by an infamous spider, the very name of which can bring stark fear to the seemingly bravest of adults. Heck, 15, 20 minutes is all I'd need.

The kid was sent home, spent an uneventful night, and had a mild headache the next morning.

In case report number two, a 54-year old man reached into a pipe to clear out a spider web and was most appropriately bitten in defense by the spider being attacked. The thumb swelled and pain was felt. The next day, the swelling subsided as did the pain. I've had plants nail me far worse than that.

So much for the evidence, and that's all of it, too. I didn't leave anything out.

Vetter went on to say various things, how important it was to identify potentially nasty animals and yadda, yadda, yadda. One thing that stood out was a curious chunk of missing knowledge concerning Loxosceles. He stated that only three specimens of the brown recluse, Loxosceles reclusa, had ever been verified in California (something I didn't know), but then said no populations of brown recluse had ever been found in the state. He made it sound as if that species was the only medically significant one, and didn't mention any of the other Loxosceles present, especially in southern California. If he had a copy of the ATS recluse and hobo spider manual, he wouldn't have missed this, but then, if he had a copy he might not have written this paper in the first place.

The Chilean recluse, Loxosceles laeta, is commonly found in southern California. This spider is the largest of the recluse spiders found in the US and is strongly suspected of having the most "potent" venom. The desert recluse, Loxosceles deserta, is known from central and southern California. The Arizona recluse, Loxosceles arizonica, is known from southern California. The Russell recluse, Loxosceles russelli, is known from southern California. The Baja recluse, Loxosceles palma, is known from southern California. The martha recluse, Loxosceles martha, is known from southern California. The Mediterranean recluse, Loxosceles rufescens, is known from California, most likely in southern California.

In short, California is lousy with recluse spiders; seven of the 13 known species are found there, especially in southern California. This is more by far than any other state. How did Vetter miss this? It could have made quite a difference in his paper.

In the last 75 years or so, many workers have tried and failed to implicate one species of spider or another as a horrible threat to humanity, possessing terrible, nasty, icky and very ill-mannered venom with poor taste (or maybe it tasted poorly). Some species of Phidippus (Salticidae, jumping spiders) and Cheiracanthium (Clubionidae, sac spiders) were implicated as having potent anti-human venom for a time before being discarded as candidates due to common sense and non-reproducible data.

Sometimes, workers literally try to scare-up funding by getting the public excited and demanding the terrible threat be dealt with. Perhaps the most notable of these occurred with a bark scorpion, Centruroides exilicauda, in the 1960s' in Tucson, Arizona. The story goes that they needed research funds, something that's perpetually lacking with most arachnologists. They began tickling the media's interest with creepy tales of horror that probably would have done Rod Serling proud.

They raised a ruckus, apparently secured some funds, and did some fine studies on C. exilicauda. It's too bad they didn't also include Centruroides vittatus, which some scorpion scientists suspect has venom a little "hotter" than C. exilicauda. The fund-raising methods may be a little off track, but C. exilicauda can kill people whose immune systems are absent or damaged, such as infants, the elderly, people with one or more chronic diseases, or those allergic (you always have to say allergic, because if you don't, that one in 156 zillion people this might remotely apply to will immediately drop dead).

The downside is we now have an intensely feared animal where one didn't exist before. The scorpion's reputation has been ruined, probably for as long as humans still roam this planet and can chew gum at the same time. For healthy folks, the fear of the scorpion will always be far more dangerous than its actual sting.

I don't believe Vetter wrote the article to drum up funding, but I also believe there wasn't enough significant scientific material in it to justify its publication. Had I been a reviewer, I would have rejected it with no hope of resurrection. The article is published in a journal read by ER physicians, so it will probably be ignored and won't raise much of a fuss, even the good parts where he strongly suggests preserving the spider's body and finding an arachnologist to identify it.

Why was it published?

We all know wasps and bees inflict painful stings. Should we conduct a census on the possible medical significance of every one of the thousands upon thousands of species of wasps and bees? Maybe, it would be great fun for many entomologists.

Would they all be accepted for publication in a medical journal like this one? Heck no. Almost all medical types know what wasps and bees do. They are aware of the possible allergic or other reactions or cross-reactions that can occur with these creatures.

Then why was Vetter's paper published? Because of arachnophobia. Even the academic medical experts have a fear, uneasiness, or at least a suspicion of those mysterious spiders and other yucky arachnids. They are willing to believe the absolute worst with precious little evidence. By publishing in a journal directed at certain physicians, he likely avoided review by other arachnologists or other scientists familiar with this field.

So, as for A. aperta, a spider "previously considered harmless," it is still considered harmless by anyone that has even casually glanced through this paper.


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