The Indigestible

Shelley Batts (a ScienceBlogger) posted some comments on different kinds of stings, along with a scale for rating which hurt the most. That led me to muse on some of my own experiences with our local pointy objects.

Arizona’s territory — on the western side — is pretty much entirely comprised of the Mojave Desert. With a very few riparian exceptions, this means that for the most part you’ll find flora and fauna optimized to survive in arid climates, though not quite as completely sere as, say, the deep Sahara.

Over the next few decades, we might see some shifts toward increased desertification — the damming of the Colorado removed a major source of aquifer recharge in the form of periodic flooding, and Phoenix, Las Vegas and most of Southern California are putting a tremendous strain on water resources. Reduction of riparian zones has led to a reduction in atmospheric humidity, which has had quite a negative effect on rainfall. The Colorado, which used to flow all the way to the Gulf of California, now peters out miles away from its original delta, which is essentially a dry washbed today.

The net is that the desertification process is being accelerated. This part of the US is one of the few areas where real estate values will probably go into an irrecoverable tailspin and acreage might one day be worth about as much — and be about as habitable to humans — as a plot of land on, say, a remote mountain peak. Damming the river has damned the Mojave.

In this part of the world most of the life survives by being scaley, hard and/or possessed of sharp edges. Think of the desert tortoise — essentially midway between a Galapagos tortoise and a box turtle — or the horned lizard (”horny toad”) and you’ll have an idea what I mean. For the most part, this wildlife is harmless to humans, but some of it can be nasty if it ends up in the same place as we are.

How nasty? Well, that depends on your definition.

In the scale Shelley published, for instance, paper wasps were placed at a 3 for sting pain (the scale just goes up to 4). I don’t know if I’d agree with it; the pain might be relative. I got pegged by a paper wasp a few years ago (fortunately, it was happy with the one sting and didn’t feel a need to repeat the performance). It felt like someone had jabbed a hot soldering iron into my shoulder.

There was a deep and persistent burning sensation that went on long after the sting, but was by no means excruciating, though I suppose if I’d been hit on the earlobe or lip I might have a different opinion. It hurt, sure, and I wouldn’t want to be stung again, particularly not more than once; but it wasn’t blinding agony.

I was advised to look out for signs of blood poisoning and tetanus; apparently wasps are potential carriers of some nasty microorganisms.

There are a couple other flying insects larger than paper wasps that live in this part of the world and which can deliver stings if provoked. The more menacing of the two is the tarantula wasp, a large black creature that’s actually quite beautiful, as long as it’s far enough away to remain an abstraction.

Tarantula wasps can delilver a potent sting, but they ordinarily target tarantulas (hence the name). Their venom paralyzes the spider and the wasp lays an egg inside the still-living arachnid. When the egg hatches the larvum devours the tarantula, matures and emerges as another wasp.*

There are also some rather large and intimidating bees (mostly of the leafcutter variety), but for the most part they’re harmless to humans. They’re solitary rather than hive-dwellers, and for that reason much less likely to sting. They are, however, huge — an inch or more in size — and can startle you with their casual, buzzing hovering behavior. As tempting as it might be, defense with a tennis racket is probably not the best idea.

Mostly around here (NW AZ) I’ve been stung by the local large black ants, harvester variety. (The Mojave Desert also has the red variety, but mostly up here they’re black.) They’re pretty aggressive if you come across a nest or trail and disturb it deliberately.

They’re not ambush-style predators, though; it’s easy to avoid them if you’re paying attention. Harvester colonies are characterized by a good-sized patch of bare earth around the anthole, denuded by the efforts of the insects. A good-sized colony can occupy a few cubic yards of soil, aerating and replenishing its carbon and organic content, and at a safe distance watching the ants at work can be fascinating. They move fairly quickly and — typical of most ant colonies — in an apparently disorganized way which still manages to get a tremendous amount of work done.

Usually I’ve been hit in the knees because I’ve stood still too long near a colony, and one has managed to crawl up my leg without my noticing. The knee is how high they usually climb before becoming constricted by clothing and panicking. The stings feel a little like being poked repeatedly by a straight pin. Getting my earlobes pierced hurt less than the ant stings, but was about the same as their pincers.

For other somewhat scary ground-dwellers we have tarantulas, solifuges and scorpions. Of the three the most dangerous is probably the generic scorpion, though it’s just the bark scorpion that is truly venomous enough to be a danger to non-allergic humans. In general scorpions stay quite clear of humans in the wild; they have ciliated pads on the underside of the abdomen that allow them to feel your footsteps when you’re still quite a distance away. They’ll recognize you’re very large and try to keep well away from you.

Often scorpions will hide in dense underbrush, beneath rocks or fallen limbs; sandals or bare feet are a terrible idea for walking through a lot of the Mojave, which is characterized by such things as creosote, cactus patches and Joshua trees. Boots are de rigeur here.

Tarantulas are also venomous but not particularly aggressive most of the time, except during the mating season (around August). They prefer to keep clear of humans but can sometimes end up inside by mistake. Fortunately they’re fairly slow-moving spiders over large distances and can be captured easily under an inverted bowl. They’re webless predators that control creatures such as crickets and are good to have around, though I expect their bite could be painful.

I’ve kept tarantulas before; they’re simply not very dangerous to humans and their fearsome reputation is largely undeserved. These spiders don’t tend to bite unless they’re provoked, and they open their chelicerae to display long, glossy black fangs in a distinctively threatening fashion. The intention is clear: keep back, you big hairless monkey.

Non-venomous but spooky, the solifuge (”sun spider”) runs fast, is desert-sand colored, and possessed of an extremely impressive set of mouthparts. Like tarantulas, they’re webless predators, but they aren’t actually spiders. Their bodies can get up to a couple inches in length and, while they don’t envenomate, I wouldn’t want to be hit by one. (There is also a Magic card, Giant Solifuge, which has inspired me to build an Arizona-wildlife theme deck. I’ll post on that at some future date.)

These are also relatively aggressive; I was once chased by one. Unfortunately I had to kill it.

Somewhere between paper wasps and harvester ants, pain-index-wise, is jumping cholla,** partly because you usually get several spines in the leg, not just one, and because the spines are barbed and tend to hurt more going out than in. Removing them without tools (a la kitchen tongs) is a further guarantee of more spines in your fingers and thumbs.

Generally I get cholla pads when I’ve passed just a little too close to one on a hike. A foot or so of distance should be enough, but it’s a good plan to give cholla as wide a berth as you can manage without looking like a complete coward.

The cactus’s rationale is propagation. The reason for the long, barbed spines and the jumping behavior is precisely what happens — the pads embed themselves in the flesh of passing animals. At some point later the animal works the pad free and, optimally, allows a new cactus to take root somewhere else. This is considerably less pleasant than embedding seeds in sugary fruit, but it obviously works.

Cactus spines, by the way, are all that remain of their leaves.

This isn’t an exhaustive list, of course, nor is it meant to be; there are plenty of other chitinous creatures in the Mojave which are actually or potentially dangerous, as well as reptiles to watch out for. But those are generally well-known and obvious — I thought it might be interesting to cover, here, some of the lesser celebrities in our index of pointy-pokey life.

As for dealing with it — well, I’m here, and I’ve dealt with it for the majority of my life. It helps to view these creatures not as menaces or pests, but rather as animals which have evolved elegantly into their ecological niches (tarantulas, for instance, are so successful that they haven’t changed significantly for tens of millions of years), and which can be seen to have a beauty that, once it’s studied and understood, is not so much something to fear as a thing to respect — and, perhaps, admire.

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* All together now: It’s the ciiiiirrrr-cllllle of liiiiiiiiife … and it mooooooooo-ves us allllllllllll…

** There really is such a thing. Anyone who insists there are no jumping cacti is wrong. I consider jumping cholla and mosquitoes to be two elegant proofs of the nonexistence of a benevolent god. Petulant, childish and psychotic, maybe. Benevolent? Between malaria and the feeling of yanking cholla out of your flesh, hell no.