On a recent weekend, on the fifty-four-acre grounds of Project Native, a native plant nursery just minutes from the Orion office, a small crowd gathered beneath a willow tree. Noah Charney, who is slender, sharply featured, and probably not much older than thirty, was crouched on his heels, peering under a wooden bench. Charlie Eiseman, in a backpack and sandals, narrated: “That’s the cocoon of an ichneumon wasp; they parasitize spiders.” There are thousands of species of this particular wasp, Charlie explained, nearly all of which pupate inside other insects. There are cricket wasps, cicada wasps, aphid wasps, spider wasps—“There’s a wasp for everything,” he said.
Noah and Charlie are coauthors of Tracks and Sign of Insects and Other Invertebrates: A Guide to North American Species, which won the 2010 National Outdoor Book Award and is probably the first insect tracker’s field guide in existence. The two friends drove down from Vermont to raise some money for Project Native, promote their own work, and lead small workshops for the day. The book itself—all 592 pages—isn’t exactly light reading: according to the jacket copy, the book “offers details for identifying beetles, spiders, flies, ants, butterflies, moths, dragonflies, earwigs, mayflies, crickets, grasshoppers, centipedes, millipedes, scorpions, earthworms, slugs, lacewings, wasps, bees, damselflies, alderflies, crabs, and many other invertebrates from the sign they leave behind.”
It turns out that the “sign” insects leave behind is pretty much everywhere. Spend enough time staring at a leaf, or a stone, or a fence post and you can’t miss it: eggs, scat, casings, galls, burrows, droppings, secretions, coverings, mounds, tracks, trails.
I watched Charlie study a leaf fluttering near his shoulder. After Noah finished with the ichneumon wasp, Charlie directed the group to the egg of a green lacewing, which, he said, if you looked close, dangled vertically from the underside of the leaf. I looked close. So did the guy next to me who had a pair of binoculars around his neck, and we didn’t see anything. Then Charlie pointed it out with his fingernail: there it was—tiny, the size of a carpet fiber, and wiggling in the breeze. A woman with a floppy sun hat leaned in with a magnifying glass.
Before bugs, Noah and Charlie led wildlife tracking seminars at Hampshire College and at the University of Massachusetts. Noah has a PhD in evolutionary biology, and Charlie is a wildly passionate naturalist. “We kept seeing these flat disks under rocks, and we were never sure what they were,” Noah told us. “We figured there should be a guidebook about that kind of thing—so we made one.” As the book came together, the two friends crisscrossed the country, looking for insects. “We once drove all the way to this one rest stop in Texas to see a leafcutter ant,” said Charlie.
Ahead, Noah was staring with incredible intensity at a barn wall from a distance of about six inches. (This activity has attracted unwanted attention from the police more than once, Noah told us.) There were wasps living in the roof’s overhang, a kind of paper wasp, which, unlike other wasps, doesn’t build a protective envelope around its nest. This nest was attached to the roof by an extremely delicate-looking stalk.
“Do you guys know why it hangs off a little stalk like that?” asked Noah.
“Ants?” replied the woman in the floppy hat.
“That’s right. Wasps formulate a special anti-ant poison, which they lacquer on to the stalk of their nests so the ants can’t climb in.”
Before I got a chance to get a good look at the nest, Charlie pulled the group into the barn and pointed at something in the rafters. “That,” he said triumphantly, “is the work of a feather-legged orb weaver,” a spider that makes egg sacs that look like three-dimensional stars suspended in air. As we looked on in wonder, Charlie kept saying things like, “I’ve never seen such density before.” And: “This is unbelievable!” As he spoke, I watched Noah upend a picnic bench and examine it like some kind of ancient text. He was looking for spider poop, he told us, which looks like miniature bird poop—white, with black dots at the center. (When Charlie added that the stuff was practically dripping off the walls in the barn, a few of us pawed at our shirt collars and wrinkled our noses.)
Charlie signaled for us to move toward a pocket of trees. I was glad to move; it was getting hot in the sun, and it turns out that a lot happens bug-wise in the transition space between field and forest. Charlie held a brown, brittle-looking leaf in his hand. “Skeletonizing,” he said, is what caterpillars and other insects do to a leaf when they move in for shelter—it’s the scratchy brown stuff that spreads from a leaf’s veins outward. I had seen this kind of thing a million times, and I was excited to have an explanation. According to Noah, different caterpillars do different things to leaves: there are leaf rollers, leaf folders, leaf tiers, and leaf miners. And, like shelters everywhere, there are secondary and tertiatry and quaternary competitors for these spaces once the initial tenants move out.
There was more. Near my foot was the spot where a goldenrod gall fly wintered inside a plant, and then burst out by inflating its forehead like a balloon. A few steps down the trail, on an aster, Noah spotted a case-bearing leaf beetle, which, he explained, built a tiny house from excrement, climbed inside, and went on his way. Soon, we were spotting the evidence of bug business all over the place: we saw a fly lose a battle with a predatory fungus, a raft of mosquito eggs bob in a puddle, a crowd of ants march to dinner, a slug plod his way to an appointment with a leaf.
When I asked Charlie about the meaning of an odd-looking white spot on a tree trunk, he looked closely and then shook his head. “Not everything is something,” he said, “but many things are.”
Scott Gast is Editorial Assistant at Orion. Find out more about Noah Charney and Charlie Eiseman, and purchase a copy of their book, at NorthernNaturalists.com.
Image credit: André Karwath for Wikimedia Commons.