Raspberry fields forever? Japanese beetles are the scourge of fruit growers, arborists, and casual gardeners alike. (Photographed by Michael D. Wilson)
By Greg Westrich Photographed by Michael D. Wilson
I stand in the backyard holding a plastic bucket containing several inches of soapy water with airy foam on top. It’s a cool morning, the second week in July. I snatch a sluggish Japanese beetle off a skeletonized potato leaf and drop it in the bucket. It sinks through the soap bubbles into the water, where it will drown.
I walk along each of the 10 raised beds and two strips of garden, collecting beetles. They shine like pounded copper. Their wing covers — called elytra — send light glancing in all directions off the ridges that run their length. Their heads are metallic green, but depending on the angle of the light sometimes appear the same copper color as the elytra. Along the thorax, on each side below the wings, are five tufts of white fur.
I cannot win. Experts don’t talk about getting rid of Japanese beetles; they talk about managing them.
All the beetles are almost exactly the same size, roughly a centimeter from the tip of their frond-like antennae to their pygidium. Their bodies are rounded domes. As I pick one up between my index finger and thumb, it wiggles, extending its two hind legs like articulated needles. Its legs are stout enough that they feel capable of drawing blood from my finger. The elytra feel like tiny scythes. I drop the beetle in the bucket and examine my fingertip. There are tiny cuts and tears in the whirls of skin.
Two beetles sit on top of one another on a feathery cosmos leaf. I hold the bucket under the leaf and knock them in. Before they’re warm enough to fly, Japanese beetles elude capture by dropping off their perch toward the ground. Later in the day, after the sun has raised their body temperature, flight is their preferred means of escape. It makes them much harder to collect, which is why I am spending my morning patrolling the backyard.
In 15 minutes, I have nearly 50 in my bucket. Any soap foam is gone now. The dead and dying Japanese beetles look almost black. They’ve turned the water the color of weak tea. I set the bucket on the back steps. Later in the day, I’ll capture another 40 or 50. They’ve only recently begun to emerge. Their numbers will increase through July and August until they’re a noisy swarm. I cannot win. Experts don’t talk about getting rid of Japanese beetles; they talk about managing them.
Japanese beetles eat 300 different kinds of plants. They eat leaves, flowers, and fruit. From year to year, they favor different plants. Two years ago, they were mostly on my strawberries and blackberries. They also killed a young apple tree. Today, I found not one on the strawberries, nor any on my surviving apple tree.
I hate Japanese beetles. I get a perverse pleasure in feeling their scratching legs on my fingertips, trying to escape my grip, and I have been known to laugh out loud as I drop beetle after beetle into my bucket.
If you collected one of every multi-cellular species on Earth — every plant and every fish, every mammal and fungus, every bird and reptile, every animal and creepy crawly — one in five would be a beetle. There are 4,000 species of mammals, but more than 350,000 kinds of beetles. In North America alone, there are 24,000 species of beetles, nearly 2,900 of which can be found in Maine.
Japanese beetles are members of the scarab family, a large group of diverse and often showy beetles. The family includes recyclers such as dung beetles. The scarab venerated by the ancient Egyptians was one of these and gave the family its name. Some are bumblebee mimics and important plant pollinators. Others are attentive parents that dig burrows and feed their growing young bits of rotten leaves. The scarab family also includes june bugs that noisily crash into windows and screens on early-summer nights across eastern North America.
After lunch, I step out the back door and pick up the bucket. A sharp metallic tang rises from the darkened water with the floating carcasses. I walk the flowerbed along the back of the house collecting beetles. They seem especially fond of black-eyed Susans, most of which have damaged petals and at least one beetle nestled against their dark-brown centers.
As soon as I disturb a plant, the beetles take flight. Their flight is fast and loud. They are not adept at maneuvering. One clinks against the right lens of my glasses, then heads in a straight line across the lawn to where the peas climb a trellis.
On the head of a daisy, a bulbous flower-crab spider holds a Japanese beetle in its embrace. The spider is white, the color of the petals, with yellow lightning bolts on it abdomen. The comatose beetle is larger than the spider. I have never seen one fall prey to anything but me. As an experiment one August, I live-captured a handful of beetles, cupping them in my hands, and tossed them into the chicken yard. The hens ran over to investigate. They fought each other for a chance to peck at the beetles, then turned away in apparent disgust. Maybe Japanese beetles taste bad, or maybe their hard exoskeletons discouraged the chickens. Whatever the reason, I learned that I was on my own in ridding the yard of them.
Japanese beetles were first discovered in North America at a nursery in Riverton, New Jersey, in 1916. It’s believed that some larvae hitched a ride in a shipment of iris bulbs from Asia before 1912, when the U.S. government began inspecting plant and food shipments. From New Jersey, they ate their way across the country. In 1939, an adult Japanese beetle was found in a car getting off the ferry from Maine in Yarmouth, Nova Scotia. By 1972, despite federal and state efforts to contain the beetles, they had crossed the Mississippi River. Today, they can be found in every state east of the Great Plains and all of eastern Canada.
The beetles are native to Japan and northern China, where they’re not major pests. Parasitic wasps, diseases, and other natural factors keep them in check. Here in North America, there are few natural controls. Each year, the USDA estimates, Japanese beetles cause $460 million in damage to crops, ornamental foliage, lawns, and golf courses.
Much of the damage is done by the larvae. Japanese beetle grubs live in the soil, eating grass roots. The grubs are inch-long, plump white worms with brown heads and legs at one end. They lie tightly curled in the soil. Chickens and other animals love to eat them. Most summer mornings, I find dozens of small holes in my lawn where a skunk has dug up grubs overnight. Lawns and golf courses with infestations of Japanese beetle grubs often develop rings of dead grass. Replacing damaged sod and fighting grubs account for almost half of the economic cost caused by Japanese beetles.
As winter creeps down into the ground, the grubs burrow deeper into the soil and remain inactive until spring. But as soon as the soil warms, the grubs begin feeding again until they pupate. In Maine, the adults begin to emerge around the Fourth of July, sure as backyard bottle rockets, an unwelcome harbinger of midsummer.
Bucket in hand, I stand looking down at the row of beans, the purple beans hanging below the canopy leaves. Many of the leaves are skeletonized. Japanese beetles eat only the soft, fleshy meat of the leaf, leaving the veins intact. Most of the damaged leaves have at least one beetle on them, some of them six or seven. The beetles pile on top of each other in slow-motion orgies.
I have collected beetles at least once a day for three weeks, but the number keeps growing. A wave of discouragement washes over me. I knock the beetles into my bucket five and six at a time, their wings buzz as they try to fly before being trapped in the soap bubbles. A six-spotted tiger beetle, like an emerald-colored drop of mercury, scuttles along the dirt beneath the beans.
I contemplate the dozens of pesticides that can kill adult Japanese beetles. There is carbaryl, but it kills earthworms, bees, and fish. Cyfluthrin would take care of the beetles — and some songbirds as well. Permethrin, esfenvalerate, and bifenthrin would kill all of the insects in the yard and maybe the birds too.
I could spray something like imidacloprid or halofenozide in the spring to kill the grubs, but there are problems with this approach. First, most pesticides that would kill Japanese beetle grubs would also kill grubs of useful beetles and other ground-dwelling insects. I don’t want to turn my yard into a lifeless wasteland to make it safe for vegetables and flowers. Second, many of the adult beetles in my yard probably didn’t hatch here, as Japanese beetles fly up to a half a mile to find food and a mate.
There are traps that use pheromones to attract beetles, but there is also evidence to suggest that they attract more beetles than they collect. It’s as if Japanese beetles evolved to defy attempts to control them.
Recently, researchers have been excited about an organic pesticide made from geraniums. Geraniums, it seems, are one of the few plants Japanese beetles can’t eat. When adult beetles feed on their leaves, they fall paralyzed to the ground and remain comatose for about a day. In the lab, the treated beetles recovered to eat again, but in field tests, most died. As of yet, sadly, this promising line of research has not led to products I can use on my gardens.
Another morning, I step outside onto my back porch and lean against the rough wooden railing. There is a large moth resting near my hand. It has a metallic-blue body and red eyes. Feathery antennae arc out from its head, and its wings are dusty-black teardrops edged in red. It’s a Virginia ctenucha, the largest of the wasp-mimic moths. To me, it looks more like a giant lightning bug. Even though they are active during the day, I’ve never seen one before.
With a smile on my face, I grab my bucket of soapy water and walk out into the backyard. The day is already warmed to 70 degrees. I begin, as I often do, with the flowerbed along the back of the house.
After catching the first few beetles on black-eyed Susans, I realize that most of the flowers are encircled by clouds of tiny red-bodied insects not much bigger than a pinhead. They are too small and too fast to get a good look at, but they’re probably micro-hymenoptera wasps that parasitize other parasites. If I hadn’t been looking so closely for Japanese beetles, I’d never have noticed them.
As my hands collect beetles, my eyes wander, taking in the abundance of lively movement. Distracted, I catch only about half the beetles. Many of the flowers are being visited by green sweat bees and bumblebees with full sacks of pollen. A pair of orange-and-black Atlantis fritillary butterflies flits between flowers. While they feed, their wings rest open, then close slightly and reopen, like relaxed breaths.
I zigzag through the vegetable garden, half-heartedly collecting beetles. Even if I catch them all, my yard will still be overrun next year. I spend more time looking for other insects. Rather than trying to control the beetles and letting my failure frustrate me, I try to manage myself. Collecting beetles becomes a walking meditation. I open myself to the experience of things I would otherwise miss.
At the back of the yard, hundreds of big dipper fireflies lay their tiny eggs in translucent rows on blades of tall grass. A garter snake lies coiled in the grass nearby. Grasshoppers popcorn out of the weeds, unaware they risk becoming the snake’s lunch once it warms up enough to hunt.
I continue my circuit, bucket in hand, with a calmness I haven’t felt since before the first Japanese beetles emerged. Maybe it is reparation enough for the damage the beetles have done.