The earliest written record of human revenge against the grasshopper was etched into a tiny tablet of greenish black stone more than 5,000 years ago. The tablet, measuring slightly larger than a matchbook and inscribed in pre-cuneiform-era pictograms, recounts how a Babylonian holy man drove away a plague of locusts, then laid a curse on them.
Not that it helped. Grasshoppers have bedevilled human plans and their crops ever since. The biggest outbreak of desert locusts in seven decades is attacking eastern Africa even now. An estimate in 2020 reckoned that, every day, a single swarm in Kenya of 200 billion insects was eating as much as the human population of Germany. Food across the region has become precarious for millions of people. The United Nations Food and Agriculture Organization calls the current surge “a scourge of biblical proportions” and has launched a locust hub webpage to track swarms by satellite.
In the past several years, South America has been hit too, its first locust plague in six decades. And in North America grasshopper outbreaks have struck the three prairie provinces, parts of British Columbia and the US west in recent years. While these haven’t caused as much loss as the African outbreak, the eruptions carry reminders of the panic of the Dirty Thirties, when pitiless swarms of grasshoppers in the prairies ate not just the remnants of wizened crops but also clothes off farmers’ limbs.
And things are poised to get worse. Droughts and heatwaves, fuelled by climate change, are on the rise. These ramp up the ability of some grasshoppers to produce eggs. Warmer temperatures also push the insects’ metabolisms higher, meaning they need to consume even more food than normal.
But while the crop-gobbling has an ancient hold on the human imagination, it’s only one part of the complicated grasshopper story. Canada has more than 100 species of grasshoppers, and only a few of them are capable of episodically ripping through a quarter-section. As unlikely as it may seem, many other types are instead critical to preserving the highly endangered grasslands ecosystem. Grasshoppers, for example, are an essential food for wild birds. Some, such as the Turnbull’s grasshopper, which gorges on Russian thistle, eat only weeds.
“If you were able to easily see the flow of energy through a grassland,” says John Acorn, an entomologist and lecturer at the University of Alberta, “you would see it flowing through the very abundant grasshoppers—flowing from the sun to the plants, through the grasshoppers and into the birds and other insects.”
And alongside other threatened insects, including such pollinators as bees and butterflies, some of those ecologically indispensable grasshoppers seem to be in freefall. Climate disruption, habitat loss and dramatic shifts in bird populations are all in play.
“Some very weird things are happening, and some are good but some potentially are very bad,” says University of Lethbridge entomologist Dan Johnson, who is funded through the Canadian Agricultural Partnership and is one of the world’s foremost experts on grasshoppers. Some species, for example, are expanding their range. And in Alberta’s north, for some species the typical five-year pattern of growth followed by decline is now squished into two years. Reasons unknown.
While there are no comprehensive studies that show exactly how insect populations on the prairies are changing, the red flags are disquieting. Johnson has been monitoring grasshoppers for many years at the Alberta Conservation Association’s Silver Sage Project south of Manyberries, for example, and has tracked a grim decline among some of its 40 species of grasshoppers. Many types of mountain grasshoppers are becoming sparser, and so is a non-pest group called band-winged grasshoppers, a favourite repast of birds.
Ironically, Johnson says, pest-control measures that decades ago killed off many types of grasshoppers are now used far more parsimoniously. One would expect that trend to lead to increases in the populations of non-pest grasshoppers. But it’s not happening, for reasons he continues to examine. “If the only thing that was hurting grasshoppers was us spraying, then right now they’d be back in record numbers and everything would be cooking out there in the ecosystem,” Johnson says.
While we don’t know exactly how grasshoppers are faring, the fate of the grassland songbirds that rely on the insects for food is better known. The 2022 State of the World’s Birds report, published by BirdLife International last September, tracked a 42 per cent drop in grassland birds in North America from 1968 to 2018. In sheer numbers, that’s roughly 700 million fewer birds in just 50 years.
The disappearance in Alberta has been stark. In the 1990s Johnson would routinely spot vast numbers of a dozen species of birds as he conducted insect surveys. “Now, you go to the same sites, and it’s just like the dead zone,” he says. “So, where are they?” But the disappearance of birds—like the let-up in chemical spraying—hasn’t helped grasshoppers either.
All of this matters, Johnson says, because counterintuitive as it may seem, as goes the grasshopper, so goes the prairie. One study, for example, shows that grasshoppers make up more than 85 per cent of the diet of nestling chestnut-collared longspurs. Another found that for sharp-tailed grouse, a key indicator of the health of the prairies, grasshoppers are a diet staple. Endangered burrowing owls rely on grasshoppers, and so do prairie owls of all sorts. Grasshoppers “hold up the food web,” Johnson says. “Without them, massive loss would happen.”
Psoloessa delicatula, Brown-spotted range grasshoppers, overwinter in soil and grass as miniature hoppers, emerging in early spring just in time for baby birds to feast on them.
Grasshoppers are marvels of evolution. Every continent except Antarctica has them, and each one features the good-hopper/bad-hopper morality play. The 600 or so species that inhabit North America likely evolved in Mexico or in the mountains of Nevada and Arizona during the last Ice Age. Then, propelled by powerful back legs and leathery forewings, they walked, jumped and flew northward as ice sheets retreated.
They’ve developed a suite of quirky survival skills, Johnson says. Most of them lay eggs an inch or so under the ground toward the end of the summer, producing a single new generation a year. The embryo grows inside the egg for a while and then puts the brakes on, going into hibernation during the coldest parts of winter. They survive because they’ve mastered the trick of making what amounts to antifreeze in their blood. Once the weather warms up, the embryo finishes growing and pops out of the egg.
But others take a different tack. Some, like the brown-spotted and velvet-striped grasshoppers, hatch before the cold weather and spend the winter in bits of soil and grass as miniature hoppers, emerging in early spring, just in time for baby birds to feast on them.
“And even after being aware of this for decades, I have absolutely no idea why they’re not dead,” Johnson says. “I mean, I can see living a day or two at minus 10, with the wicked cold and wind and drying conditions. But all winter? It’s like a miracle.”
These different life cycles have evolved so that if one species of grasshopper gets into trouble, another can take its place in the food chain. This diversity is evolution’s prime mechanism for building resilience, rather than stability, in an ecosystem. But the reasons why one population thrives while another fades away remain mysterious.
“I go out every weekend in the summer and just make sure I’m familiar with what’s happening with all the species,” Johnson says. “Which ones are up this year, which ones are out, which ones are late, which ones just completely disappear. And even after 30 years of chasing them around and trying to keep tabs on them, I don’t know why.”
For millennia, the triggers for grasshopper swarms were equally opaque. But ever since humans began farming, we’ve been all too aware of the havoc the swarms could bring. Tales of locusts infuse ancient Egyptian, Chinese, Hebrew, Roman and Greek texts. “Due to the extent of their devastation and the spectacular nature of their migratory swarms, locusts have left an indelible mark since ancient times in the minds, beliefs, literature and arts of many cultures all over the world,” write locust specialists Michel Lecoq and Arianne Cease in February 2022 in the journal Agronomy. Both the Bible and the Qur’an cite locusts as one of the ancient plagues of Egypt, a divine retribution for sin. China alone has been recording locust outbreaks for 3,000 years, logging more than 800 separate events. In North America, six voracious swarms of the notorious and now extinct Rocky Mountain grasshopper, each lasting at least two years, struck the Great Plains between 1818 and 1875 alone, shaping tales of the settlers forevermore.
More recently, the X-Men comic book franchise introduced the villain The Locust. This evildoer creates a swarm of giant locusts with an ionizing “magno-ray” to devour crops. “Feed well, my pretties,” he coos. “Feed well! Now only I, your leader, am present to hear your song of mounting menace! But soon the world shall know the meaning of that sound… and live in terror of it!”
Some farmers have told me, ‘Wow. Now I get it. We should conserve some grasshoppers and just not bother spraying.
But magno-rays aside, where does a swarm come from? In 1921 the Russian entomologist Boris Petrovitch Uvarov finally decoded the mystery. It turns out that about 25 of the planet’s 6,700 grasshopper species can alter themselves from benign, shy insects into the terrifying swarms of locusts that devastate crops—but only under pressure from very dense grasshopper populations. The drier and more abandoned an area, the better for incubating swarmers.
These hoppers change colour, size, shape and even brain size, essentially shapeshifting into eating machines. The process is called gregarization, meaning that they transform into what’s known as their “gregarious” phase, the opposite of their “solitarious” phase, and then band together into dense, marauding mobs of insects.
The behaviour of some species can shift within mere hours. They move fast, too: hordes can migrate hundreds of kilometres in one night, eating everything they come across. That includes the leaves off trees and handles off shovels.
On the grasslands, the attacks have spawned generations of ingenious eradication campaigns, including bounty systems, grasshopper “armies,” burning, beating, drowning, plowing eggs into the soil, crushing them with horse-drawn “hopperdozers,” dynamite, flamethrowers and poisons of all kinds. A popular formulation in the 1930s was sawdust, bran and arsenic.
Today, chemical insecticides are still the go-to to control pest grasshoppers. But these poisons are shorter-lasting now, far more targeted and more regulated, to prevent persistent damage to the landscape.
As well, in an attempt to prevent outbreaks, nations now monitor desertified areas to find out whether they’re becoming cradles for locusts. Some countries have established early-warning systems that trigger immediate insecticide programs. Arizona State University has set up the Global Locust Initiative to make sure knowledge about outbreaks remains accessible across the world. That’s especially important now, because climate disruption is likely to reverse any recent progress in controlling outbreaks, making the events more frequent, more severe and more apt to strike in new locations, according to the Agronomy article.
Alberta maintains a pest-grasshopper population map and forecast, plus a late-August count of adult grasshoppers capable of laying eggs, conducted by agricultural fieldmen—professionals with applied agricultural or environmental science backgrounds. The Bruner’s spur-throat grasshopper, for example, could be shaping up to be a problem this summer in the Peace River region, and crop-pest grasshoppers have been on the rise in the warm, dry south and eastern borders over the past two years, carrying risks of an outbreak.
A mountain bluebird bringing food to its babies. One study shows that grasshoppers make up more than 85 per cent of the diet of nestling chestnut-collared longspurs.
Modern safeguards aside, the old evil-grasshopper battle stories remain tenacious. And, in Alberta at least, they’re taking hold once more. Despite many types of grasshopper appearing to be in decline, hotter weather is encouraging still other local species to multiply.
“I would say that in the last six months, more than at any time in 10 years, the news services and the people I bump into, they’re all just grasshopper, grasshopper, grasshopper,” Johnson says. “It’s back on their radar, and it wasn’t for a long time.”
It’s his cue to remind people that a grasshopper is not necessarily a blight. It could even be a blessing. To that end, he’s put together illustrated guides explaining the differences between good and bad.
Johnson’s basic message? If the grasshopper sings, or if it flies before June, or if it has brightly coloured or black hind wings that you can see as it flies, it’s not a crop-eater—meaning farmers shouldn’t spray.
Pest species, on the other hand, hatch in late May and early June. They are brown or black and always have little wing buds rather than large wings that fold back. One of the big hungry ones with a fondness for grasses, cereals, pulses, canola and safflower is the two-striped grasshopper, with its characteristic twin lines of spots running along the back.
Johnson also posts grasshopper ID photos prolifically on social media. “I throw them on to try to get people that follow me interested,” he says. “And some farmers have said, ‘Wow. Now I get it. You know, this is really interesting. We should conserve some and just not bother spraying.’ It’s much better than it used to be.”
As for Acorn, he marvels at how grasshoppers manage to continue to play a key role in the grasslands ecosystem. They sing the soundtrack of the prairies, he says. What you hear on a warm summer evening in Alberta is mainly stridulating grasshoppers, rubbing a small, roughened surface on their hind legs against the front wings. Some make soft, lisping sounds in the grasses, while still others emit sharp calls across the wind, nestled up at the side of warm cliffs.
To him, it’s a lesson in being humble. In honouring the unexpected. And in being careful how we treat this tremendously complex world we find ourselves inhabiting.
Alanna Mitchell is a journalist, author and playwright fascinated by how science, art and society intersect.
____________________________________________
