January 1987, page ee Weber State College Comment, ers: Beauties or Beasts? ~~ alk leg about hairy, waving shudder. in Not black the spiders, air, Gary and Miller. with most He one people kind of likes the crawly creatures. Most people, though, have trouble understanding the affection. “I do have a fascination for spiders,” said Dr. Miller. “I think they‘re interesting looking.” Burrowing wolf spiders have been the subject of research by Dr. Miller, a zoologist at the college, for the past four years. The spiders are of the order of arachnid and have eight hairy legs that carry a body which can grow as large as an inch-and-a-half. The body itself has organs, depressions and openings that baffle scientists as to their function. Some openings are thought to be sensors for airborn chemicals, but others, shaped as slits, have stumped researchers. Not that there are hosts of scientists working with burrowing wolf spiders. Dr. Miller and his wife, Pat,(who is the expert ‘at categorizing the invertabrates) are the only ones in the country actively studying the ecology of the burrowing spiders. “Spiders are so misunderstood. _ things about them that we don’t There are many understand,” Dr. Miller said. Wolf spiders usually live in the desert, and have a non-posionous bite that feels like a bee sting. Their eight eyes provide fairly well-developed sight, and four or five different types of hairs on their legs give them the ability to feel vibrations, smell chemicals in the air, especially those emitted by other spiders, and sense slight air movements. They inch-and-a-half. : This magnification (top center) shows the spider's face from the underside. The jaws and fangs are clearly visible. The end of the wolf spider's leg (middle left) come equiped with claws the spider uses in grabbing prey. The spider is covered with hairs (middle right) and are shown here magnified 100 times. The hairs have small openings that are thought to be chemical receptors used for sensing other spiders. The burrow of the spider (bottom right) has an opening of about the size of a quarter. Woif spiders seldom leave the burrow. their food outside of the body and then injest it,’’ he said. row, bursting through the wall and surprising the unsuspecting spider. How the centipede knows exactly also have organs All this takes place on the rim of the burrow, and, that keep track of the stress in each leg as the spider moves. The burrowing wolf spider is a ground dweller, and opts to dig a small hole, or burrow, for its home rather than spin a web. The wolf spider can make for the female especially, that is as far as the spider nature. ever gets from its hole. Dr. Miller and his wife are raising 30 wolf spiders in a laboratory at the college. They feed them silk, but does so only when making a burrow. “The spider uses its forelegs to lay out the silk, then it gathers it up. The spider collects the sand that sticks to the silk and comes to the top of the burrow and flips it out. They can dig a burrow in about one hour,” he said. —— Dr. Miller (upper left) and his wife are the only ones studying burrowing wolf spiders. The spider itself (upper right) can grow to a body length of an The diameter of their holes is about the size of a quarter, and can be up to three feet deep. The wolf spider lives all of its life in the burrow, coming up each night to watch for prey. Even when catching food, however, the spider will never go farther than ‘The only other time the spiders leave the burrow is when the male is looking for a female, and when they need only feed once a wingless flies and is another ground mystery up dog of food to tive and disbursement cycles. “Feeding and reproducing: Those are the big issues in the life of a spider,” he said. burrow,” Dr. leaving the female to the 150 to 200 young she will hatch in a spring litter. About half of the young spiders leave the burrow relatively soon while the rest stay through the first winter. Some balloon away by spinning webs that are caught by air currents, and others simply crawl, but during the first of the winter about original 90 litter percent make die. rowing wolf spider. They fly into a burrow, paralyze times is located said. After the male copulates with the female he wanders “off into the sunset somewhere and dies,” the mother’s The wolf spider can sense prey up to two feet away, but the unsuspecting insect has to almost walk colder crickets, spider keep them alive for research on the spiders’ reproduc- leave an inch from the top of the burrow. during the Miller the young Roughly 15 adulthood. right into the spider to be caught. Spiders are coldblooded and can slow their own metabolism so that where it to Wasps are one of the natural predators of the burthe spider with its stinger, and lay eggs inside the spider. The spider is unable to move, but is still alive, and its warmth incubates the wasp eggs until the month. young hatch and feed on the insides of the still-living The spider jumps on and grabs passing insects, spider. then rolls to its back. While the insect’s legs flail “It’s all a part of the diversity of nature. It’s harmlessly in the air, the spider paralyzes it with a beautiful in its own way,” Dr. Miller said. fang bite. The spider then injects digestive juices into _ Centipedes also feed on the wolf spider. The manythe stunned quarry and sucks in those juices once the ‘legged insect cannot win an attack by climbing down victim is turned to pulp. “Wolf spiders masticate the burrow, so it tunnels alongside the original bur- What prompts some row through the understood. Most in the bur- winter while others go is spiders are highly canibal, young to remain not but some wolf spiders seem to have a social behavior while they are young that keeps them from eating each other. “The whys of that should keep Pat and me busy for the next 10 to 15 years,” he said. Occasionally Dr. Miller knocks one of the arachnids unconscious with carbon dioxide and, with a very tiny scalpel, shaves their legs. The exercise is an attempt to figure out what role the chemical receptors in the ends of the leg hairs play in the reproduc- tive cycle. Dr. Miller also will kill and dissect a spider periodically, a step he’s not particularly fond of. “I have to admit there’s some tenderness for them,” he said.