Solpugid: Arch Predator of the Desert

FOCUS ON NATURE SOLPUGID: THE BUG FROM HADES

Okay, it was a party, and a glass or two of wine had been consumed, so when this large unidentified hairy thing zipped across the carpet and scooted up into the innards of Annette Cordano's recliner chair, reactions ranged from "Holy cow! What was that?" to rather more colorful phrasings that can't be printed in this magazine. In a flash, Annette jumped from the recliner, and a couple of us tipped the chair on its back and banged its sides to see if we could evict the rug racer and pop him (or her) into a glass jar for a better look. "Did you see how big it was?" someone exclaimed. "That thing was six inches long!" I probed the recliner's works with a small flashlight. There were hundreds of hiding places in there, even for a six-inch something or other. Finally I detected movement and spotted something, cowering, it seemed, behind one of the chair's coiled springs. Then, Mason jar at the ready, we gently poked at the critter with a yardstick until out it scampered to be scooped instantly into a dustpan and dumped into the jar. We gathered around for a closer look. It was about two inches long, not six, but big enough for anything able to locomote that fast. Its coloration was sandy, hard to see on desert terrain, but no camouflage whatsoever on a dark carpet. Its hairy legs were jointed, so it was an arthropod that much we knew and it had four pairs of them, not counting the two "feelers" that it held aloft as if testing the air before it. "Check out those pincers," someone said, referring to a pair of formidable weapons that projected from just beside a pair of beady eyes and seemed to take up more than half of the front portion of the little beast's body. None of us had ever seen anything like it. "The bug from Hades," someone quipped. Marty Cordano, who makes a living catching and photographing fast-crawling things with lots of legs, stepped forward. "You know," he said, "I saw something like that in a book once. Sun spider, I think it was called." "Oh, sure, now that we have this dangerous animal safely under control, Mr. Know-It-All comes on the scene," we mocked. The spirit of the evening required it. Marty was right. The sun spider, aka windscorpion (it runs like the wind), is one of the aliases of the enigmatic creature we captured and later released into the desert that night. It's scientific name is solpugida, Latin for "sun dagger," and it's neither bug nor insect. It is an arachnid, rather, a subgroup of arthropods that includes spiders and scorpions. There are more than 50 species of solpugids in the arid Southwest, and only an expert, of which there are few, can tell one from another. In Mexico it is called matavenado, "deer killer," a bit of hyperbole no doubt intended to tout the solpugid's fearful predatory tools. I asked University of Arizona entomologist Carl Olson what solpugids prey on. "Anything that gets in their way," he answered. Anything they can get their chelicerae, or jaws, around, he might have added.Once on a television documentary about Nature in the arid Southwest, I watched a sun spider crush and devour a creosote grasshopper while the narrator intoned: "Sporting the largest jaws relative to body size of any animal in the world, this nonvenomous relative of spiders and scorpions makes quick work of any small prey." The "small prey," in this case, happened to be roughly the size of the solpugid itself, and, as I watched it kill and eat the grasshopper, I recalled scenes from another animal kingdom documentary in which a crocodile tossed an adult wildebeest into the air. Although I'd never seen one before the speedster raced across the floor that night at the party, solpugids, I've since learned, are abundant. Mainly nocturnal, they're seldom seen. Howard Lawler, a curator at Tucson's Arizona-Sonora Desert Museum, frequently spots them right at dusk. "They're easier to see in half light," he says. "You can kind of catch them moving out of the corner of your eye." And the UofA's Olson says that windscorpions show up regularly inside his house. Why none have appeared inside my desert home is a mystery to me. Just about everything else has from bats to bugsmost without invitation. In Nature's microworld the world of spiders, scorpions, mites, ticks, and uncountable bugs and insects the solpugid is an arch predator. Although its vision is poor it has only that single pair of simple eyes it compensates by using a pair of sticky appendages called pedipalps to see and then seize prey. Its primary tools for catching and killing are, as mentioned, speed and jaw strength. It can move very fast indeed, and once it locks onto prey with its chelicerae, its grasp is inescapable. These jaws, which work like powerful shears, take up two-thirds of the solpugid's cophalothorax. After the kill, it eats only the juiciest parts of its victims and discards the carcass. Except when mating, solpugids are solitary. When a male meets a cooperative female, he deposits seminal fluid on the ground and transfers a sperm droplet to her genital opening with his pedipalps. The female produces 50 to 200 eggs, which she lays in a burrow and stays with until they hatch. When the young arrive, the female leads them from the burrow, capturing prey and feeding them, until they can fend for themselves. It may look like "the bug from Hades," but the solpugid is not poisonous. That doesn't mean you should handle one. If provoked, it may bite. And any wound can become infected. If you discover one of these creatures in your house, don't smash it. Scoop it, instead, into a container and release it outdoors. Think of it this way: without the solpugid on the job, we might be crawling with mites, ticks, kissing bugs, and other nasty little bloodsucking beasts.