Windscorpions — don’t be fooled by their looks

Technorati Tags: windscorpions,animals,wildlife

Femal Eremobates species guarding her eggs. Photo by F.Punzo

Southern New Mexicans have been terrorized by windscorpions. Many even think they look like miniature aberrations brought forth directly from their worst nightmare. Because of their fierce appearance, many myths have sprung up about them over the years. These myths include certain death if bitten, all the way to your mother-in-law suddenly hating you if you have the audacity to touch one.

Southern New Mexicans also have a unique name they call these creatures: “Children of the Earth.” I’ve heard this name before used for a big, burrowing cricket with a huge, shiny bald head in central California. That makes sense, since it sort of looks like an infant’s head, but how anyone can attach the name to windscorpions is one of the great mysteries that can truly never be solved. Other nicknames for them are “sunspiders” and “camelspiders” (both are one word because they aren’t spiders, nor are they scorpions). Camelspiders is another mystery, as is sunspiders because most species come out only at night. New Mexico also has more of them than any other state, with the possible exception of Arizona or Texas.

One of my first experiences with windscorpions took place just south of New Mexico, at Balmorhea State Park in West Texas, so many years ago that I refuse to reveal the exact number because it may tend to incriminate me. After sunset, I’d set up my light trap and was waiting for some great desert insects to stop by. In case you didn’t know, a light trap is made up of a white linen bed sheet hung vertically on a line with one end touching the ground with as many ultraviolet lights shining on it as an entomologist can afford, which usually isn’t many. Insects and other arthropods find this irresistibly attractive, and wing, squirm, or crawl spellbound toward it. This is when I found out how smart they are. We’ve known for some time how many species of spiders that spin webs to snare prey (and only a bit more than half of the 36,000 spider species do) will learn that they will catch a lot more prey if they build the web near insect-attracting lights, conveniently supplied by humans. Not to be outdone by a mere spider, windscorpions have learned to gather around lights and feed on the insects that have fallen to the ground below the lights.

Soon, I was collecting many of the windscorpions that had made a bee-line to my light trap, along with many of the more flashy insects. As is wont to happen, this upset many non-entomologists in the campground, but I’m used to that. As more windscorpions zipped in for a free meal, I watched the ensuing carnage for hours. The windscorpions tore their prey asunder with their powerful chelicerae (loosely, jaws) and devoured insect after insect (mostly moths) that had tumbled to the ground. Once in a while, I had to wrestle an insect specimen away from one that I wanted to collect, but the windscorpion would always find a replacement for it quickly.

This type of experience is my idea of unsurpassed outdoor fun and recreation. I will never understand why anyone would want to get a gun and go out to shoot some herbivore, or take a stick with a hook on a string and pull a slimy vertebrate out of its aquatic habitat. Why would anyone do that when they can simply set up a light trap and get hours of intense entertainment watching a huge variety of far more interesting animals. Human behavior is pretty weird that way.

Windscorpions (order Solifugae) got their name because they seem to “run like the wind.” They’re a hyper group of arachnids with about 1,000 species world-wide. Perhaps 120 or so species are present in then U.S., with most seen in the arid Southwest. Some species reach nearly three inches in length. This qualifies them as one of the largest arachnids. Most hide during the day and come out at night to scamper about in a frenzied search for food or a mate, but some species (mostly in Africa) are active during the day.

As with many other arachnids, the windscorpion body is divided into two major regions; the cephalothorax, where the legs, pedipalps and chelicerae are located, and the abdomen, containing the heart, reproductive and other organs. Unlike the name may imply, windscorpions have no stinger on their tails, or even have tails at all. The abdomen is rounded at the end without any tail structure. They have thickened, sharp, pincer-like chelicerae near the mouth followed closely by stubby leg-like pedipalps with sticky tips they use to sense, capture and handle their prey. The thin, first pair of legs are often used as feelers in many species. The remaining three pairs of legs serve as more than adequate running legs. A pair of simple eyes lie on top of the animal in the head region behind the large chelicerae. The eyes are fairly keen for a non-spider arachnid, at least in the diurnal species.

Most run a zigzag searching pattern, constantly probing, prodding, exploring holes in the ground, deftly touching everything in reach of their pedipalps and first pair of legs for a bite to eat. The closest vertebrate equivalent I can think of is our state bird, the road runner. Road runners also move around quickly, devouring any insect or small reptile that moves. Windscorpions are frequent feeders, needing to replace the lost water and energy expended during their frantic activity.

As with other aspects of their biology, windscorpion mating habits are intriguingly distinctive. There is variation with species, but in general, once the male becomes mature, he gives up his zigzag search pattern for a more straight line course and begins to eat less often. One male covered nearly a mile in less than two hours while seeking out females with its human scientist eyewitness in tow across the deserts of southwestern Africa.

The male may find the female on the surface, or he may somehow sense her holed up below the surface in her burrow, and will begin digging her out. She will ascend to the surface, or if in the open, the male briskly touches her and jumps back, before moving forward and making a grab for her abdomen. If the female is unreceptive to the male’s initial advances, he won’t continue to stalk her like some other male animals do; he’ll turn tail and run off to look for an interested female.

Once the female’s abdomen has been grabbed by the male, if she is a willing sort, he will touch her cephalothorax with his pedipalps then begin a complete massage of her abdomen with his chelicerae. The female gathers her legs to her body and remains motionless, or torpid, for the duration of the mating. This component of the courtship ritual is called “female torpor induction.”

The male continues his massaging of the female, gradually working forward to her cephalothorax, until he finally stands over her, both facing in the same direction. The male holds the female’s legs and palps against his body and exudes a spermatophore (sperm packet) from the underside of his abdomen onto the female. He then quickly backs off the female, retrieves the spermatophore, lifts her abdomen up, and places it directly into her genital opening. The male will continue to massage the areas around the genital opening and the spermatophore, which may have something to do with liberating the sperm from the packet, until the female wakes up from her “torpor” and sprints away. The male usually returns to his hyper, female seeking behavior afterward.

The fertilized female will excavate a chamber and lay about 60 eggs inside it. Some females may stay to guard them, others may not. Most species of windscorpions have one or two generations per year and most males probably do not live for more than a few weeks after becoming adult.

Although infinitely interesting, they are the most difficult arachnid to keep successfully in captivity for any length of time. Even the best, most attentive arachnid caretaker can’t keep a captured windscorpion alive in captivity for more than two to six weeks. Speculation has it that penning up this normally very active animal up makes them sluggish and prone to die quickly. Some windscorpion researchers have labeled this “taming.” At least two scientists have raised them from egg to adult, but apparently you need to hatch the eggs in captivity for them to survive. Maybe they’re fooled into thinking life in captivity is normal.

Windscorpions, like many other arachnids orders, are considered 100% beneficial to humans. The main reason is that they are all predators capable of reducing the numbers of animals humans call pests. Their prey includes just about anything they can catch and subdue that doesn’t eat them first. Some species specialize on termites, while others feast on small lizards, rodents, snakes, scorpions, and numerous soft-bodied insects such as cockroaches. The worst a windscorpion can do to a person is nip at fingers with their sharp pincers, but unless they’re one of the large ones, they can’t even draw blood. Combine this with the fact they have no venom, and thinking folks realize that windscorpions make extraordinary allies, even if they may not think they’re gorgeous animals as I do.