The Wheel Bug of Life

Photograph by Ronald F. Billings of the Texas Forest Service, USDA Forestry Service Archives, image 3226085.

Since we began gardening several years ago—when we moved into our first house—we have grown our vegetables in raised beds. This has always been primarily a practical decision. Had we topsoil to till, I would gladly till it, amend it, and leave it where it lies. But in our present home we had to cart in, wheelbarrowful by wheelbarrowful, two pickup truckloads of soil and compost just to get started. There was no point digging it into solid clay; far better for our backs and our crops simply to dump it on top and build a box around it to keep it in place.
But however practical our intentions, the raised beds also have the aesthetic effect of delineating the garden from the yard and the woods. Every good gardening magazine preaches the importance of giving your garden a border—the better for neighbors to appreciate your industry, I suppose; lacking clear boundaries, the garden might appear accidental. I think the real reason is deeper than aesthetics. The border of wood makes the garden seem so organized, so logical—at least in April, before the Early Girls have turned the bed into a thicket of vines only a machete could slash through. Clearly marked boundaries say, to anyone who might ask, that what’s inside is mine. They suggest control, over processes and outcomes. Inside is nature domesticated; outside is wilderness.

Raised beds make it awfully tempting for a gardener to give himself too much credit for control over what happens in them. It’s a conceit I’ve learned not to allow myself, and what’s changed my mind is bugs.
     The first year we planted a garden, we had space and sunlight enough for only an eight-by-twelve-foot bed: a learning experience, we called it. We decided to stick with purely organic methods, partly on principle and partly out of stubbornness to see if we could do it. So by early May we began noticing the bugs. This is North Carolina, and bugs here come early and often. At this house we had everything from aphids to black widow spiders. Nothing should have surprised us.
     One day in late May Kathy returned from inspecting the garden and informed me, excitedly, that I absolutely had to see this bug she had just found on a tomato plant. I went outside and looked, and, indeed, it was without a doubt the ugliest bug I had ever seen. Grayish-brown, over an inch long, a round, spiked fin on its back that made me think of dinosaurs, and massive jaws (for a bug at least) that looked like they could swallow the dog.
     Lacking a field guide to learn its proper name, we christened our discovery, naturally enough, the Ugly Bug.
     But as we watched the little critter holding his ground on the tomato leaf, my wife raised the question that neophyte organic gardeners must frequently face: is this a good bug or a bad bug? Meaning, will it eat my plants, or will it eat the bugs that eat my plants? If the former, we wanted to be rid of it; if the latter, we were glad to have it stay.
     Nothing in my education—and I have more of it than I care to recall—had prepared me for this decision. I thought back to ninth-grade biology, but all I could remember was something about six legs and a thorax, and also those termites that build the big mounds in the tropics somewhere. I had, that year, dissected a giant grasshopper, but vague memories of insect innards and of the overpowering stench of formaldehyde were of no help to me now. No one had thought it worthwhile to teach me how to answer the two most important questions you can ask about an animal, namely Can I eat it? and Is it likely to eat me? In other words, is it or is it not a predator?

We decided, after some debate, to leave the Ugly Bug alone. It was just too cool to squash, and we both felt that anything that ugly must surely be a predator. There was no logic to this, just the instinctive feeling that this thing was too nasty to eat plants for a living. So we let it live, and kept an eye on it. The Ugly Bug decided, apparently, that we were no threat to it, either, and took up residence among the tomatoes.
It turned out that we were right to let it stay. We did, eventually, see it eating a caterpillar (my inner ten-year-old wants to tell you that this was really cool), but that was after Kathy had made the ultimate sacrifice for science by trying to touch the thing and getting rather painfully stung. Now, privy to the contents of an Audubon Field Guide, we know the Ugly Bug to be Arilus Cristatus, the Wheel Bug, so called because of the wheel-like protrusion on his back, the scourge of tomato hornworms and Japanese beetle larvae. He’s one of our best friends in the garden, and we look for him again every spring—from a safe distance, of course. (For the benefit of curious folk like my wife, Audubon notes that Wheel Bug "can give a painful stab when it defends itself from a careless handler." Thanks, guys.)
The business with the wheel bug taught us an important lesson—not, perhaps, to live and let live, but at least to know what the heck you’re doing before you start squashing stuff. The wheel bug made me rethink the idea that a border of two-by-twelve pine could make our garden somehow separate from the rest of nature. That first season’s bumper crop of yellow pear tomatoes owed as much to him, I think, as to us.

Obviously, we’re not always so lucky. Last summer, in our new home, we built a fence around the grassy part of the yard to keep our two dogs in. The front part of the fence, what you can see from the road, is split rail with wire behind it, and we planted morning glories along its length. By July, they were absolutely spectacular—and so were the bugs trying to eat them.
The Japanese beetles I simply squashed as I found them—I have long since lost any fascination I might once have had with their metallic sheen, and I have the comfort of knowing they’re not a native species anyway. But what really caught my eye were a few dozen roundish beetles, shaped like slightly oversized ladybugs, with a clear outer shell and metallic gold underneath. Imagine a gold watch with a glass case. Our new field guide told us they were Golden Tortoise Beetles; we did not need it to also tell us that their favorite food was the leaves of morning glories. We already knew, from the holes they left in the leaves—and also from the converse of our previous assumption about the wheel bug. If the wheel bug was too ugly to be prey, these guys were too beautiful to be predators.
We let the tortoise beetles live, too. They were as beautiful as the morning glories, in their own way, and they didn’t do too much damage. After a few weeks they were gone; something—birds, perhaps—must have eaten them. Not everyone in the food chain can afford to be so magnanimous, I guess.

I once watched a neighbor checking over her garden—also in raised beds, but much neater and more precisely built than ours—for insects. It was a source of great pride to her that she used only proper organic methods, and she had bought, at the beginning of the season, a sealed box of ladybug larvae from a gardening supply company. Now she discovered, to her consternation, that her plants were crawling with aphids. "I can’t understand what happened to my ladybugs," she said, reaching for her spray bottle of pyrethrin, "I haven’t seen them at all. I keep spraying the aphids but there’s always more."
     She proceeded to soak her plants with poison—organic poison, and relatively quick to break down, but poison nevertheless—and bemoan the lack of loyalty among her ladybugs. I also heard her wonder, later in the summer, why she hadn’t seen more bees pollinating her squash flowers. In the end I believe she had to do it herself, with a cotton swab.
     The following spring we moved into our current home, and we noticed, at the end of April, that the beautiful rose of sharon at the side of the house was swarming with aphids. You literally could not see some of the leaves for the aphids, and we were seriously worried that they would destroy the tree. But we realized that the tree was several years old, and that it had assuredly survived such onslaughts in previous springs. We decided to leave it alone but keep an eye on it.
     A day later we found the first ladybugs on the rose of sharon. A week later the aphids were nearly gone.

The lesson I have learned from bugs is that while I have been on this earth only a few decades to muddle in the garden and "modern" agriculture has had only a century to attack what it sees as problems, nature has had millions of years to work out solutions, and we do best to trust her experience. Bugs eating too much of the vegetation? Along comes another bug to eat them.
By killing bugs indiscriminately, by sterilizing nature to give ourselves the illusion of control, we lose the good with the bad—as well as the opportunity to learn that there is good in both.
The Wheel of Life turns, and nature finds a balance. Someday, I expect, even Japanese beetles and kudzu will fall into line.
Someday. Give it time.

— April 1999

Postscript: Wheel bugs on the Web

The University of Florida provides a page of information on wheelbugs, their behavior, and why it's best not to let them bite you.
More photographs of wheelbugs at various stages of development are available from the USDA Forestry Service Archives.