Bug-watching in the Santa Ritas

JEWELS OF THE NIGHT

You take one look at Carl Olson and think: "Here's a guy who guides big-game hunts -mountain lion pursuits, maybe, with horses, hounds, the works." He wears a floppy-brimmed Australian bushwhacker hat, and his size 13s are shod in a pair of sport sandals that are de rigueur among adventurers nowadays. He's beard-ed, and, to top it off, he's big, say six feet three inches and 240 pounds. So when you discover that the wild crea-tures Olson pursues are seldom more than a few inches long, usually much smaller, you say, "Bugs? You catch bugs and study them? Oh, that must be interesting." Olson brushes away any hint of sarcasm. No one's buggier about bugs than Carl Olson. One evening in late July, Olson, associate curator of entomology at the University of Arizona, leads a bunch of us on a bug-watching safari into Box Canyon in the Santa Rita Mountains south of Tucson. The pro-gram, "Jewels of the Night," is a joint offer-ing of Baja's Frontier Tours, an eco-touring company, and Pima Community College. The first part of the adventure, a nature walk led by Olson and the Arizona-Sonora Desert Museum's Mary Erickson, has begun though it's barely after 6 P.M. The temperature in Box Canyon's oak-juniper woodland is a comfortable 86° F., 20 de-grees cooler than Tucson. Through the evening, the temperature will continue to drop, and when the black-light party breaks up around 11, many of us will be wearing sweaters. Not long into the nature walk, most of the 30 or so participants cluster around Olson, who has sliced open an oak gall pulled from the leaf of a roadside Arizona this is as far as we got," Mary Erickson tells me. "Carl keeps finding stuff." On the edge of the group, a young boy, squatting, notices an ant emerging from a hole, crawling a short distance to drop a bit of soil, then immediately reentering the hole. "Hey, Carl, look at this!" he yells. Olson pockets the oak gall and begins to spin out information on ants. "See how the ground around the hole is cleared?" he asks. "This is a harvester ant; it's just be-ginning to dig a hole for a colony. As the white oak. Inside he discovers the micro-scopic larva of a gall wasp. This gall is tan, about the shape and size of a golf ball. Others, Olson explains, can be red and woolly in appearance; some are nipple-shaped. Using a hand-held lens, we take turns examining the larva while Olson ex-plains that galls are formed by a substance deposited on the leaf by a female gall wasp. "We started about a half hour ago, and colony grows, the workers will remove all the vegetation several feet back from the hole. Harvester ant colonies can get huge. Some grad students at the UofA dug one up with a backhoe and found more than 20,000 workers in it. They went down through soil, caliche, and rock about 10 feet and still didn't find the queen." Erickson moves to Olson's side, nudges him with her elbow, and says, "Carl, if we If we don't go back now, we won't get dinner before dark." So we all hike through the wash in the canyon to where Piet Van de Mark, owner of Baja's Frontier Tours, has set up picnic tables in a white oak grove. To whet our appetites, Van de Mark and crew serve a variety of cheeses, grapes, apples, blush and white wines, soft drinks, and an array of home-baked breads. The bug watchers range in age from 10 to perhaps 80. There's a physician in the group, an ethnohistorian, a newspaper columnist, a computer repairman, a retired military officer, an illustrator, a number of teachers, and, of course, kids, the most wide-eyed bug watchers of all.Dinner is next, not a picnic, an actual sit-down dinner with plates, flatware, napkins. Rotisserie barbecued chicken is on the menu with tabouli and mango salad.

During dinner, Olson rigs two black-light stations, one in the dry wash, the other approximately 100 feet upslope. Black-lighting refers to ultraviolet light, those bands just beyond violet in the spectrum, out of our visual range (therefore black) but within range for insects. The black-light stations are sheets stretched over frames, illuminated by ultraviolet fluorescent tubes. Scientists hypothesize that insects use light for navigational orientation. Two small portable generators power the lights into operation. While we're eating, all kinds of bugs home in on the light. Few of these creatures are bugs, strictly speaking. Technically, some are not even insects but members of another class altogether - spiders, for instance, which are arachnids. Persnickety taxonomists might scold you for calling them bugs, but not Carl Olson. His Internet e-mail moniker is Bugman, and the preface to his book, Insects of the Southwest, is titled "The Bugman's Philosophy."

When we approach the black-light stations, they're swarming with life. So many bugs! They get on everything - your clothing, your hair, your bare legs, your eyes. Not much to worry about, though; not one venomous insect appears.

One of the first bugs that Olson plucks off the sheet is a graybird grasshopper. Gripping the grasshopper's thorax between thumb and forefinger, he says, "Try this: Push against its feet with your finger and feel the resistance, the strength in its legs. Insects are incredibly strong." So many bugs! The tiny click beetle, which alarms predators by flexing its thorax to produce an audible "click"; the Manduca moth, a night pollinator whose tongue unfurls to a length of three and a half inches; the bombardier beetle, which mixes chemicals inside its body then bombards its enemies with a noxious jet spray.

If there are "stars" of the black-light bug world, they are metallic beetles and large colorful moths. Someone on the other side of the sheet shouts, "Oh my gosh!" and we all scurry to see what aroused that response. There, clinging to the sheet, is the first of several scarab beetles drawn to the black lights. It's an "Oh my gosh" and more. Emerald-green with golden threads running down its back and fine gold and silver highlights elsewhere, the beetle is truly a jewel of the night. Later one attaches itself to a woman's shirt front. In any other context, we might mistake it for an expensive brooch. At one point, Van de Mark uses a butterfly net to capture a huge moth flying around a lantern at base camp and takes it to Olson for identification. It's a polyphemus moth, so named for the cyclops who imprisoned Odysseus in Greek mythology until Odysseus escaped by blinding Polyphemus. With a wingspan of six inches, the feathery tan polyphemus moth is a splendid creature, but its most striking feature is a solitary eyespot on each hind wing. Predators are warned off by these "owl eyes." Other moths have them, too, but the ones on the polyphemus are different: They're diaphanous, like cello-phane panes. Even Olson is speechless. Well, nearly. "I've seen a lot of big silk moths such as this," he says, "but in 20 years, I've seen only a few of these."

The serendipity of the polyphemus moth's appearance is well-timed. "Okay," Van de Mark says, "time for dessert," and we troop back to the picnic area for cherry cheese-cake and coffee. It's getting late.

As I drive out, I'm more aware than ever of bugs flying toward the headlights, thousands of them, all jewels of the night.

WHEN YOU GO

For information on Jewels of the Night and other eco-tours, contact Piet Van de Mark, Baja's Frontier Tours, (520) 887-2340. Wear hiking shoes and carry extra clothing on these outings. Even on the hottest days, night temperatures drop sharply in mountain canyons.