Monthly Archives: December 2020

Fool Me Once… A Cautionary Tale

Or, in this case, fool me twice.

A few months back, I was “vetting” some photographs that had been submitted to the North Carolina Biodiversity Project’s Arachnid page when I came across this photo, submitted as possibly being Agelenopsis pennsylvanica (C. L. Koch, 1843), one of the grass spiders (sometimes called “funnel weavers”) of the family Agelenidae.

A Grass Spider

Now, right off, it didn’t look to be Agelenopsis to me, for a number of reasons, none of which are easy to specify–it just didn’t look right.

When all one has is a photo, though, identifications can get tricky, and–my not being from ’round these parts–I didn’t recognize what seemed to me to be what should be a readily identified species.

I am generally hesitant to start searching online photo collections looking and hoping for a match: After all, not only do many spiders look similar, but online photos can be misidentified. So, I did the next logical thing: I asked a highly experienced person also working on the project if he had any thoughts.

He immediately responded with a likely ID of Barronopsis texana (Gertsch, 1934), another agelenid genus known from NC…and he was spot on, of course.

As B. texana was a species which I’d never seen (or even heard of) before, I naturally did some literature searching to learn something about it. First off, I learned why I was unfamiliar with it: It occurs from NC south through Florida, thence west into Texas: All my collecting has been in the Midwest and Northeast, so I’d simply never come across Barronopsis before.

So, armed with this knowledge, I was ready for my next encounter, right? Um…no, this is where the “fool me twice” bit kicks in, I’m embarrassed to admit.

A couple of months later, a neighbor brought a living spider to me, about which I immediately proclaimed (in my very best know-it-all-tones) “that’s an immature wolf spider!” and then–using the Occam’s Razor Theory of Spider Identification–promptly guessed at a species.

OK, I’m sure you see where this is going! When I got it under the microscope it was immediately clear that this was not a lycosid (wolf) spider at all, much less the species I had guessed. Nope, wrong family altogether, its being (as you’ve no doubt already surmised) another of the agelenid Barronopsis texana, of which I had so recently been totally ignorant–and, sadly, had apparently remained.

Barronopsis texana I misidentified!

But, my suffering this ignominy did, at least, lead to a happy ending. A few weeks later, I was visiting a relative’s house some miles away when I found a spider molt skin having familiar markings. I looked around and found funnel webs on a building wall, from which webs I captured an adult female and an adult male B. texana. And this time I got it right!

Female(L) and male(R) Barronopsis texana

Morals of the story:

  1. No matter how much I think I know, there is always someone who knows a lot more.
  2. Don’t hesitate to say “I’m not sure–let me get a closer look”.
  3. This is a very cool species!
  4. It’s so much fun to learn new things!

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Is this [Insect | Spider | Snake | Critter] Poisonous?

Chances are pretty darned good that the answer to the title’s question is “No.” After all, the Cambridge Dictionary says a poison is “a substance that can make people or animals ill or kill them if they eat or drink it” [emphasis added], while the Oxford Dictionary is a bit more explicit: “a substance that causes death or harm if it gets into the body” [emphasis added].

What may be poisonous, though, is venom (rattlesnake or otherwise) which, according to the Oxford Dictionary is “the poisonous liquid that some snakes, spiders, etc. produce when they bite or sting you.”

So, basically, a rattlesnake is not a poison; in fact, “rattlesnake” can be found on exotic meat menus, and, barring any open wounds in or around your mouth, you can drink rattlesnake venom without ill effect. Or so I’ve read. This definitely falls into the “DO NOT TRY THIS AT HOME!” and “I AM SPECIFICALLY NOT RECOMMENDING THIS!” categories.

Thus, while the snakes shown below are not poisonous, they are highly venomous!

Rattlesnakes

OTOH, the venom shown being collected in the next photo is most assuredly poisonous when injected into most mammals!

So what does this mean for spiders and some stinging insects? Well, first off, it means that most simply aren’t poisonous. Insofar as I know, you can eat any spider whatsoever without fear of poisoning. (And here, I must repeat my “I AM SPECIFICALLY NOT RECOMMENDING THIS!” caveat.)

Venomous,” though is a different matter.

As of this writing, there are 48,974 recognized species of spiders in 128 families* 👇. Among these, only one family, the Uloboridae–comprising only 287 species (0.6%of that almost 49K)–does not produce venom. All the rest do, and it’s safe to assume that probably more than that remaining 99.4% of all the spiders you’ve ever noticed do produce venom.

A venomless, uloborid spider, Uloborus glomosus (Walckenaer, 1842)

Why produce a toxin at all? Well, it serves spiders the same way that venom serves dangerous snakes: It is used mostly to subdue prey, though it may be used for defense when necessary.

Thus, when people ask me “Is this spider `poisonous?'” I have to point out that almost all spiders are venomous, but more importantly, almost none dangerously so (and none poisonous).

In fact, only a tiny handful of the 48,687 venomous species known are known to be capable of causing serious issues in humans** 👇! Furthermore, many (most?) spiders are just so small that they cannot deliver venom to humans, their fangs being unable to penetrate human skin.

In fact, while I have no idea what spider has the smallest fangs in proportion to its body, I do know that Scytodes atlacoya, the spitting spider I find so interesting, has a carapace (the head-thorax part) generally ca. 3-4mm (ca. 3 pennies thickness) wide: Their fangs are only ca. 0.1mm long, or about the thickness of 2 sheets of paper–not much of a threat!

The face of Scytodes atlacoya. Those barely visible reddish spots on the ends of her chelicerae are her teeny fangs!
(The photo is inverted–she was hanging upside down.)

On the other hand, the dysderid spider below illustrates sort of the opposite ratio: you can really see the fangs on this beauty! This common species lives in leaf litter and duff, where they feed on woodlice, the critters sometimes called “sowbugs” or “pillbugs.” It uses those disproportionately large fangs to penetrate their armored plates. (But fear not: They’re only ca. a centimeter long, and not aggressive.)

Dysdera crocata
(This slightly cropped photo by Joseph Berger, Bugwood.org is used under
Creative Commons License)

So the long and short (ha!) of it is: Most critters aren’t poisonous (some are, though–e.g. several species of puffer fish are deadly poisonous to eat!). OTOH, almost all spiders are venomous, but it’s unlikely that one would bite you anyway. Furthermore, if you do somehow provoke a spider into biting you, it’s extremely unlikely to be one of those few species whose venom can actually cause a problem in humans. So, honestly: Don’t sweat it–far more Americans are killed by horses every year than by spiders!


*👆 Per the authoritative World Spider Catalog
**👆 Of course, as with any bites or stings, some individuals may have allergic reactions to the proteins in spider venom.

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