Insectopedia (2 page)

Beebe also reported a different phenomenon: a steady stream of insects of many species—cockchafers, chrysomelid beetles, vespid wasps, bees, moths, butterflies, and “hosts upon hosts of minute winged insect life”—passing together through the migration flyway in a massive motley emigration that apparently took place every year.
⁷
All that minute insect life was too small to be counted. But aphids, an indistinct haze, will swarm at densities up to 250 times greater than that of butterflies. In fact, these tiny ones—the aphids, the thrips, the microlepidoptera, the smallest beetles, the smallest parasitic wasps, all barely visible to the human eye—form the overwhelming majority of species and individuals of the class Insecta, testimony to the fact that evolution shrank the insects over the millennia even as it exploded their numbers and differences.

The giant dragonflies of the late Paleozoic, with their thirty-inch wingspans, are no more. As insects miniaturized, they developed their near-endless variety of aerodynamic body shapes and their specialized muscles for super-high-frequency wingbeats. Of the million or so species currently described, the average adult body length is at most a mere two tenths of an inch, and the median length is significantly less. Nonetheless, it is the larger, more visible insects, those four tenths of an inch or more in length (that is, at least twenty times larger than the average), that command the attention of researchers. If we subtract the huge volume of genomic studies of the fruit fly
Drosophila melanogaster
, the literature on tiny insects is scant.
⁸
It seems clear that the relative abundance
of miniature insects that Glick recorded in the air column is less a result of their being so easily carried aloft than a result of the fact that they so outnumber their larger relatives.

Glick himself reported strong-flying dragonflies at 7,000 feet over Tallulah, large insects flying well above the 3,000-foot boundary and flying so comfortably that they shifted direction to avoid his plane. Other researchers, including Beebe, recorded minute weak-flying insects—the supposedly involuntary dispersers—close to the ground, well below the proposed threshold. Researchers of insect flight now talk about the boundary layer in more fluid terms, as a variable region near the earth’s surface in which wind speed is less than the speed at which a particular insect is capable of flying, a zone that varies with the strength of the wind and the capacity of the insect. Within the boundary layer, the insect is able to orient itself actively. Above the boundary layer, its direction of flight is strongly influenced by the prevailing winds, and the animal adapts to, rather than overcomes, atmospheric conditions.
⁹
Given that only about 40 percent of known insects fly at airspeeds greater than three feet per second and that such timid winds—so gentle that a human can barely sense them—are generally found only close to the ground, most insects exercise full control over their directionality only at an altitude of three to six feet.
¹⁰

Yet beyond the boundary layer, thousands of feet into the troposphere, it’s likely that only a small proportion of these animals—those without wings (such as spiders and mites), those that become too cold, and those suffering from exhaustion—are passively carried. From the tiniest to the largest, migrating insects are out there actively flying, flapping their wings, maintaining or varying their altitude and direction despite the strength of the winds around them. Sometimes they hover, sometimes they glide, sometimes they free-fall, sometimes they soar. They do what they can to evade birds in the daytime and bats at night. Rarely do they drift along like pollen in a breeze. Or plankton in the ocean.

No, aerial plankton is not a good name for these animals. They don’t live in this medium; they occupy it temporarily. And their residency is full of calculation and action. Their exodus is triggered by the impulse to find new habitats and to encounter new hosts. Sometimes their flights are short, repeated dispersals; sometimes they are vast migrations from
which the traveler may or may not return. In either case, there is little passivity. Takeoff is oriented to wind and light. If the animal is strong enough, flight is often against or across the wind. Butterflies and locusts streaming in formation may suddenly interrupt a low-level journey with a dramatic collective rise to catch a current at thousands of feet. Even tiny insects appear to seek out thermal drafts. In the upper reaches of the air column, the minute ones take paths strongly determined by the wind, but inside the airstream they hold steady, beating their wings, adjusting their direction and altitude. And then they alight, often prompted by scent or reflecting light, using their bodies to bring themselves to earth.

Forty years ago, Cecil Johnson, the author of a classic text on insect migration and dispersal, pointed out that many, perhaps most, individual insects die on these voyages, but “this is the price such species pay for finding their habitats.” Johnson conjured an image of a planet under surveillance, “the surface of the Earth is thus scanned very effectively as millions of individuals, flying on air currents, continuously encounter suitable and unsuitable situations.” When the situation does not suit, they soon take off again in search of a better location for feeding or breeding (or some other activity obscure to us), following “a direction determined either by the wind or themselves.”
¹¹
It is a fact of planetary life, a great “diffusion system” that transports immense populations of animals “day after day, year after year, century after century.”
¹²
What happens to the notion of an invasive species in the face of this continuous and irrepressible traffic of short- and long-range travel, dispersal, and migration? What is left of a notion that everything has its own place, that everything belongs somewhere and nowhere else, that boundaries are inviolable, that with vigilance and chemicals this hyperabundance of willful and random life can be brought under control? Perhaps this was what Glick glimpsed 3,000 feet above Durango, face-to-face with the pink bollworm moth, its flapping wings gleaming in the high-altitude sunshine.

Stop. If you’re inside, go to a window. Throw it open and turn your face to the sky. All that empty space, the deep vastness of the air, the heavens wide above you. The sky is full of insects, and all of them are going somewhere. Every day, above and around us, the collective voyage of billions of beings.

That’s the letter
A:
the first thing not to forget. There are other worlds around us. Too often, we pass through them unknowing, seeing but blind, hearing but deaf, touching but not feeling, contained by the limits of our senses, the banality of our imaginations, our Ptolemaic certitudes.

“What’s going on? What is it?” I called out to Seu Benedito as we put-putted along the Rio Guariba in the afternoon sunshine. “What’s happening?”

A hundred yards away on the far bank, under the heavy trees, which just yesterday had sheltered a broken wooden house, the poorest on the river, was a shimmering jewel, a glittering vision of fluttering yellow, canary yellow, corn silk yellow, golden yellow. Flecks of gold were spinning from it like cinders high into the dark forest. Sparkling sunbursts were spiraling out from it over the river. “What is it?”

“Oh,” Seu Benedito laughed, “the
borboletas de verão
, the butterflies of summer. They’re back. You’ve never seen them?”

That day they were everywhere. An explosion exploding the world, dressing it in strange new color, tripping it out with unexpected beauty. As we chugged along the river, we saw that each house we passed had surrendered to the transformation. Thousands of yellow butterflies had settled on roofs and walls, occupied wooden porches, finally turned Amazonia into El Dorado, encrusted this quiet village in layers of gold.

When we reached home, there were golden-yellow summer butterflies dancing around our house too. High in the eaves, all around the porch, low in the muddy yard where the pigs rooted under the floorboards. They floated and soared, and I took a picture to hold on to that day and the few that followed before the insects left.

This is the kitchen at the back of Seu Benedito’s house, near the mouth of the Amazon in the Brazilian state of Amapá. I lived here for fifteen months in 1995 and 1996, and this is what it looked like in the late-afternoon sun on the day the butterflies arrived. Sometimes now it
seems like a dream, someone else’s story, so I take out this picture and think back to that day. See the sleepy hunting dog in the foreground? See the
açaí
palms, with their heavy bunches of black fruit? See the two giant tires that little Helton and Rosiane filled every morning with water from the creek, just out of view to the right? See the fenced-off vegetable patch? The thick wire clothesline? See the
borboletas de verão
caught in time and space like mini UFOs, just visiting, just stopping by, entering our lives, transforming everything just for a moment, showing us a glimmer of a different world, then passing on?

I look at this photo of Cornelia Hesse-Honegger in her apartment in Zürich and try to imagine what she sees through her microscope. Beneath the lens is a tiny golden-green insect, one of the leaf bugs of the suborder Heteroptera that she has been painting for more than thirty years.
¹
The binocular microscope magnifies to eighty times. The centimeter scale in the left eyepiece allows her to map every detail of the insect’s body with precision.

Cornelia collected this animal close to the Gundremmingen nuclear power plant in southern Germany. Like most of the insects she paints, it is deformed. In this case, its abdomen is irregularly shaped, a little crinkled on its right side. To me, even under the microscope the deformity is all but imperceptible. But just think, she says, how such an anomaly must feel if you are only two tenths of an inch long!

What does Cornelia see when she focuses so intently on this creature? She tells me that when she’s outside, collecting in fields, at roadsides, and on the edges of forests, she “loses herself in the animal.” At these moments, she says, she feels “very connected, extremely connected”; she feels a deep bond, as if, perhaps, she herself had once been such a creature—a leaf bug—“and had a body remembering.”

But her painting practice, as she explains it, is almost the opposite of this. When she sits down with her microscope, she no longer experiences the insect as a coevolved being but as form and color, shape and texture, quantity and volume, plane and aspect. Her work becomes as mechanical as possible. (“I want to be like a laser that goes from one square centimeter to the next. I see it, I show it; I see it, I show it,” she tells me.) At times, as in the painting below, she introduces a principle of formal randomness, selecting specimens from her collection by chance and abstracting a single structure, which she repeatedly positions at designated points on the graph paper, creating an image with no preconceived final arrangement, an image whose aesthetic origins lie squarely in the tradition of concrete art, in which she was raised.