BlO—Lancaster Farming, Saturday, January 14,1984 WASHINGTON - At night the woods are full of glowing eyes, sticky webs, spiders hanging in midair, walking sticks, owl flies, moths, and other flying things. That’s the way biologist Mark K. Stowe likes it. Just after dusk he slips into the stillness of the Devil’s Millhopper, a thickly forested state park in northern Florida, near Gainesville. Equipped with a headlamp, he usually stays until dawn looking for certain kinds of spiders that come out only at night and lurk ont he underside of leaves. At first glance they look like other members of their ancestral family, the orb weavers. But they’re different. They gave up spinning the traditional web a long time ago. Mimicking Moths Instead, these spiders get all the food they need by luring male moths. Somehow during the course of evolution they developed the remarkable ability to mimic the sex attractant odors of female moths. They capture and live on male moths exclusively. “Sometimes I’ve watched as many as four moths at a time struggle against the wind, ap parently to compete with each other to get to the female,” Stowe says. Instead, they meet a deadly fate: one of two genera of spiders, Kaira, “the snatchers,” and Mastophora, “the bola hurlers.” To catch their prey, Kaira spiders hang upside down from a silk trapeze line with their legs outstretched and snatch moths out of the air. The Mastophora spiders use a front leg to fling a short line of silk with a droplet of glue on the end. The glue instantly sticks to the wings of an approaching moth, and 'vsm BLACK LT. 6RET iBUOW BROWN PROBOSCIS MOHREY-ONE OFTHE 6TRRN6EST LOORINO RNfMRLS OPRLL THE MON KBV RINODOM /S THE PRO BOSCIS ortrunkmonkey OF BORNEO. THIS RNIMRL ms A REP-ORRNOE NOSE 3INCHES LONfyRNO HRM6S DOWN UKE THE TRUNK OF RN ELEPHANT. THIS NOSE MILL CONTINUE TP GROW /N THEM RLE FOR AS long rs he lh/es. Spiders Use Scent te Lure Moths the tethered prey is hauled in, wrapped in silk, and eaten. “I’ve never seen a moth break away from a successful spider strike,” says Stowe. “That glue has physical properties that man would be hard pressed to repor duce. Also, the bola line can stretch out up to six times its original length and absorb some of the energy of the moth’s struggle. ’ ’ It is unusual for spiders to at tract their prey, and even rarer for them to exploit the sexual signals of another insect to do it, says Stowe. “Unlike the typical orb weavers, which catch anything that happens to fly into their webs, these spiders don’t wait for insects to arrive by chance. Not that they’re fussy, but all the are able to catch is moths.” Their better mousetrap is geared to the moths’ nocturnal activities and can net them up to eight moths a night, depending on size. Some spiders can snare moths that are twice their own body length FARM SHOW Pennsylvania 4- H’ers won awards for some unusual exhibits at this year’s Farm Show. Nestled in a comer of vhe Farm Show building were the entomology exhibits. Here are the results: ORANGE GREEN LT BROWN LT. BU/E LT GREEN 6. 7. 8. 9. 10. Hunt by Night 4-H'ers Win Entomology Awards 4 PH V OQ ruT n A 0 Both the trapeze and the bola represent evolutionarily reduced orb webs. The spiders, which are found only in North and South America, must periodically re-spin these webs throughout the night. Stowe, who won first prize in an eighth-grade science fair with a project on spiders, is now com pleting his doctoral work on Kaira and Mastophora spiders at Har vard University. His field research is partially supported by the National Geographic Society. To witness all this activity, Stowe must turn off his headlamp and use special infrared viewing equipment. Moths do not display normal sex attraction behavior in even the dimmest of visible light. Vibrations fromt he approaching moths prompt the spiders to flick the bola or grab out with thier legs. To make things harder for the spiders, the same response can also be elicited by such diverse stimuli as human humming and a jet plane passing overhead. mwiuu Members 1 Edward Royer Lebanon 2 Tammy Messier Furnace 3 Brian McClue Covington Second Year 4-H Club Members 1 Becky Tice Mamsburg 2 Linda Beatty Home, 3 Pam Ross Marion Cr Third year 4-H Club Members 1 Michael Dwyer State College 2 David Beatty Home Emily Ross Marion Ctr Fourth and Fifth Year 4-H Club Members 1 Sylvia Royer Lebanon 2 Brian Petro Fur nace 3 Lewis Beaty Home Did You Know? Dinosaurs have come and gone, but the horseshoe crab is still around, and its looks have hardly changed over the past 300 million years. Only a few other creatures, most notably the cockroach, look so much like their ancient an cestors. Some pet tortoises are said to have excellent vision and strong loyalties, says International Wildlife magazine. Tortoises can recognize their owners from a distance, while ignoring strangers. Bats have been extremely valuable in scientific research that aids mankind. Research on bats has contributed to development of navigational aids for the blind, new vaccines, artificial insemination and birth-control methods, and to studies of aging and space biology. The saying, “rain is good for fishing,” is true. Insects may be knocked into a lake or stream by wind or raindrops, which brings insect-eating fish, such as bluegills, to the surface, where it’s easier for people to catch them. Raindrops also break up the smooth surface of the water, making it harder for fish to see people fishing. Only the sturdy caprenter bee can lift the flap of the Brazil nut’ miles over Paris during a 25-minute ride, a flight that was witnessed by a well-known American diplomat, Benjamin Franklin. n 1-* 4-X/-83 / / s