Late summer of 2008, I was sitting in Crossfire Canyon (here are parts two and three) at one of my favorite sandstone perches when I became conscious of a persistent buzzing noise. Looking down, I spotted an insect hovering just above the ground about a meter below me. The insect looked something like a yellow jacket, black and bright yellow in coloration, but in morphology it more closely resembled a fly than a wasp. A yellow jacket’s buzz changes pitch constantly as it moves, and it’s always in motion because it has no real talent for hovering. This look-alike hovered like a champ, so it droned at a fairly constant pitch rather higher than a wasp’s.
It appeared to be absorbed in defending a patch of dirt directly beneath it. Maintaining a constant hover point an inch or so off the ground, it ticked vigilantly clockwise and counterclockwise in the horizontal plane like the needle of a gauge, never budging from its axis except to pursue trespassers. These included other flying bugs that showed no interest whatsoever in the insect or its dirt patch but that merely passed through the cordoned airspace. After flinging itself off in pursuit, the fly returned always to settle exactly into its still point in the air like a bird landing on an invisible branch.
As I watched the fly, I shifted one foot, the toe of which overhung the rock acting as my footstool. There was hardly a lag between the moment I moved my foot and the fly’s swooping up to hover an inch out from the toe of my boot. For three or four seconds it stared down my toe. When I didn’t move, the fly swung back to its hover point below.
Its swift and direct response intrigued me. I wondered: Just how far does this creature’s awareness extend? My hand rested on my knee, even farther from the fly than my boot. I twitched my index finger just slightly. Immediately the fly zoomed up to that finger, even though after moving I held perfectly still. It hovered an inch out from my hand, facing down my fingertip. When I didn’t move, it returned to its invisible branch. After the insect settled I twitched again, even more slightly. The movement was barely perceptible, yet up zipped the fly to challenge my finger.
It was an interesting game, but I didn’t want the little creature to spend energy needlessly on my account, so I didn’t provoke it again.
Finally, after deciding conditions were to its liking, it landed on the dirt patch it had been guarding and dug rapidly. Either it uncovered or excavated a hole then entered it for a moment. When it emerged, it buried the hole and zoomed away. Except for a slight disturbance on the surface of the ground that resembled a tiny landing strip, the creature’s worksite was indistinguishable from the surrounding terrain. The fly didn’t return while I remained there.
I have no idea what the fly was doing, though its behavior suggested it protected something that it valued dearly, maybe a food cache or brood chamber. I hadn’t seen it carrying anything, so I don’t know how it might have been a food cache. I wasn’t even sure what kind of fly it was. At home, I tried looking it up. I had no luck finding an exact match. In some aspects it looked and acted like a female scarab-hunting wasp. But in flight behavior, coloration, and body shape, it seemed to fall most squarely into the hoverfly category.
Hoverflies, family Syrphidae (a pretty word meaning “gnat,” though characteristically they are medium to large flies resembling bees or wasps), are one of the world’s essential pollinator species; furthermore, the larvae of many species feed on aphids, so they offer home gardeners like myself free biological pest control. These two qualities alone make them golden players on the garden team.
Approximately 950 species of hoverfly live in North America. According to Wikipedia, every continent except Antarctica supports hoverfly populations. If you look at the poster half-way down the Wikipedia page, the insect I saw closely resembled the second and third flies in the top row.
Hoverflies are an important indicator species of the health of an environment. So I consider it a very good sign that during spring and summer they swarm my garden. Also known as flower flies or syrphid flies, they are a brightly colored bunch and besides the dash their hues add they heighten my pleasure in the garden by providing a soundtrack—layer upon layer of vibrant humming that gives the garden an acoustic shine. Because of the hoverflies that work my garden, I relate better to Yeats’ line from “Lake Isle of Innisfree”:
Nine bean rows will I have there, a hive for the honeybee,
And live alone in the bee-loud glade.
For me, it’s a hoverfly-loud garden. The honeybees don’t arrive until the squash blossoms and other later-blooming flowers unfold. Furthermore, the bees don’t visit in nearly the numbers. Other small bees, such as the solitary bee, do share the garden with the hoverflies from spring on, but the hoverflies steal the show. Here are some gorgeous close-up photographs of hoverflies.
Not since I was a child poking through the weeds in rural Virginia have I lived anywhere that supports such an abundance of insect life as I find in and around my current home in San Juan County, Utah. Gardens I grew in Utah Valley had only a fraction of the pollinating species I find here. Probably, if I had gardened differently back then, I would have drawn in more pollinators. But even so, without the concerted effort of gardeners around me to help provide floral corridors to compensate for the loss of habitat such species require, I doubt I would have found much success attracting hoverflies and bees.
But you never know. Up the street from where I lived in Payson grew a stand of milkweed, right in the middle of a residential area. Brightly-striped monarch butterfly caterpillars climbed the stalks and fed on the leaves then went about the business of metamorphosis. I had the impression that generations of butterflies had relied upon this isolated patch of milkweed for garden and nursery. I suspect that only my kids and I knew they were there.
I can’t say for certain that the hyper-vigilant fly I saw in the canyon was a hoverfly. If it was, it behaved differently from hoverflies that come to my garden. Or maybe I just haven’t learned enough about hoverflies to recognize their behavior away from flowerbeds. Whatever it was, I learned a great deal from this brush-by. For one thing, it seems that some flies have even better eyesight than I had supposed. The speed with which this one responded to my barely perceptible movements was several times faster than my own visual stimulus response time. The concentration with which it guarded its treasure—whatever it was—I would describe as “intense,” much more intense than the behavior I’ve witnessed carrion flies exhibit around a carcass. Its impressive mapping skills demonstrated themselves in its pursuit flights, from which it returned straightaway to its aerial pinpoint. This, I understood, was a creature to be reckoned with, more functional in some regards than I was. A bolt of inspiration on furious wings.
Filled with admiration for what I could perceive of the creature, I wondered what gifts it had that I might aspire to. Flying and hovering is out of the question, though I’ve harbored a secret wish to become a helicopter pilot since my mid-twenties. The insect’s reflexes—maybe a bit late to achieve that kind of lightning response time, though if I become more active I’ll improve what I’ve got and keep something of an edge on what I honed in my youth. But those mapping skills? I want those mapping skills.
Those I can still aspire to. And maybe that’s partly what the stance toward other creatures that we call stewardship involves—seeing then learning what the other knows better.