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In the early 1980s, the San Francisco peninsula (along with other large swaths of California) were sprayed from the air with the pesticide malathion in an attempt to eradicate the Mediterranean fruit fly. Jasper Ridge, however, was exempt from the spraying, leaving it an oasis of insect diversity. But as the Argentine invasion eradicates local ant species, Nate fears a ripple effect in this sheltered ecosystem when other creatures cannot find their preferred food source. (The Argentine ants are too minuscule for some animals to feed on.) The next species to go is anyone's guess.
Nate delicately squishes an Argentine ant on the end of his finger and says that like all ants we'll see today, it's female. Does anyone know why? "Yeah," nods Amber, poking at a male classmate. "After mating, you're DEAD!" She's right, Nate explains; fewer males than females of most ant species are created. The males die within three days after mating with the queen, and the annual event leaves dead ants everywhere right here at Jasper.
Amber looks through Nate's lens. On a thistle, a native Prenolepis imparis, or false honeypot ant, scurries around a tiny speck, stroking it with a leg, caressing it with an antenna. Then around to the other side of the light-green, pear-shaped speck-an aphid-for a poke. Another native ant races up the plant's stem, helping position the aphid to insert its needle-nosed proboscis into the leaf. A tiny golden drop appears from the aphid, and the honeydew-really aphid excrement-is swallowed by the second ant. The translucent substance is the ants' sweet symbiotic reward for tending and protecting the pest.
A few feet away, a column of false honeypot ants streams up and down the oak where the jays are hunting. The southbound lane is slower, the ants' abdomens swollen with tree sap. Their exoskeletons separate slightly, giving a tiger-striped effect. At the base of another oak, everyone is on hands and knees, mesmerized as an Argentine ant struggles with a dead beetle, while two more push, pull, and roll a torn-off white spider abdomen down a hole. When the Jasper hillsides turn brown in the summer, ant nests remain green, fertile with the spoils of scavenging. "They're the little creatures who run the world," says Nate, quoting Harvard zoologist E. O. Wilson. It's a biology-essay cliché, says Nate, that without insects, this would not be the world as we know it. With so many species, so much abundance, they provide every service-everything other animals do, they can do, and more. He turns to a girl pointing down at her bug du jour. "You gotta pick it up or it doesn't count."
"Oh . . . no . . ."
Farther down the trail, water thunders down 67 feet of stepped concrete into the San Francisquito Creek as the Eastsiders thread across the 1870s Searsville Lake dam. A stand of yellow mariposa lilies explodes below, while white Pieris butterflies flit just out of reach. Sunlight glitters off the marsh reeds, and a thick pillow of fog rests on the conifers atop the distant Santa Cruz Mountains. Nine banana slugs lounge in the shade, the air damp from the spray.
Joel Perez quietly tugs Nate over to an oak sapling. Atop a gently rolled leaf, a wasp is barely stuck in a few strands of silk. It tests one leg, then another, trapping itself more and more. One-tenth its size, a ghostly white spider peers from behind the leaf's curl with all eight eyes. This prey is too large to wrap and stun. It grabs one of the wasp's two remaining free legs. The spider pulls. The wasp counters. This tug-of-war continues for a few seconds until the wasp collapses backward into the tangled web.
A girl in a fluorescent-yellow parka makes a startling picture, offering a matching yellow banana slug, torchlike, on the end of a stick. That's not an insect, says Nate-but he's pleased that at least she's shifted her interest from an intense conversation about boys. Two girls watch soldier beetles mating, the male expressively raising his middle two legs on either side now and then. A few feet away, students find a striped yellow spider lying in wait, a furry green caterpillar feeding on a brilliant mule ear flower, and a honey bee pollinating an orange California poppy. On a bay leaf, a neon-yellow juvenile Mirid only a millimeter long resembles a miniature Pokémon, the base of its comical red-striped antennae visible deep inside its translucent body. Three girls squeal as a small cloud of gnats envelop them. Miguel's voice booms from down the trail. "Yuck! Look at this-it's like a plastic bag. Hey, hey, hey, Nate, come here!" Nate gently disperses the jellybean-size foam pouf to reveal a half-inch green nymphal spittlebug. "A whattlebug? What's this? Bug spit? There's a bug under all this stuff? For real?" The spit-nothing more than voided plant sap and "ooze," a viscous substance mixed with air-protects and humidifies these young insects as they feed on their host plant.
These minute observations are what Nate hopes the group carries home. "Sort of a trickle-down, they tell their friends and it snowballs, this information about something underappreciated," he says. It's about understanding biodiversity: careful observation showing why it's important to conserve every species.
Joel finds a western tussock moth caterpillar, tiled red, yellow, and black, with four gray tufts and a matching fringe of fur all around. It's almost feline, except for antennae-like projections and a tail resembling bunches of black enoki mushrooms. As Ogden Nash observed, the trouble with a kitten is that it eventually becomes a cat, and this flamboyant creature soon will metamorphose into a dull gray moth. Joel picks at something else in his net but crushes it. Nate leans over reassuringly to say that he'd be a fine scientist. Joel says he's planning to become president. How about being a scientist-president? "Yeah!" says Joel. "Like Thomas Jefferson."
Back at the docent center, nine of the teenagers cluster at two picnic tables. Their teacher, Monya Baker, breaks out sugary Mexican funnel-cake pastries. What have you learned? Nate is bowled over by the enthusiastic, accurate response. Ants are female, moths have hairy wings but butterflies don't, only insects have six legs, dragonflies' eyes wrap around their heads, there are more beetles than any other animal, spiders are mean!
Joel sits alone, scratching the sand with a stick. He's surprised that bugdom is so small and so busy. He didn't know bugs were so cool. Nate realized the visit was sinking in when Joel slowed way, way down-poking at leaf litter, finding smaller and smaller insects. The success of a bug walk is measured in how little territory is traversed. A really good micro-safari covers only 100 yards all afternoon.
Like Joel, Nate had his own transformative bug experience. In college, he was preparing to study physical therapy, but then came a taxonomic treasure hunt in a required
zoology class. While turning over a rotting stump, his teacher whispered how lucky he was to be paid for doing this. Realizing he could make a career out of what he'd loved so much since rambling through the Arkansas woods, it was conservation biology from then on. As for Joel, Nate is confident that if he gets as excited about insects or anything else as he was today, he'll succeed at it easily.
The Eastside van rumbles away and a cloud of dust settles around the edge of the forest. Umber dusk filters through the oak canopy, dappling the ground. Out of the quiet, the trees crescendo with bird calls and an occasional cicada. A small snakefly lands on Nate's sleeve and a ground beetle climbs across his shoe. Everything we disturbed is closing in again. "After you've been here awhile, everything returns, as if it all gets used to you and you become a part of it," Nate says, as softly as humanly possible.
Blair Tindall is a writer and musician living in San Francisco.
(C) 2000 Sierra Club. Reproduction of this article is not permitted without permission. Contact sierra.magazine@sierraclub.org for more information.
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