‘A scourge of the Earth’: grasshopper swarms overwhelm US west | Bugs

TThey arrive in swarms, so close that it appears as if the earth is moving. They cover roads and fields, pelt ATV drivers, and constantly gobble up grain and grass to the ruin of farmers and ranchers.

A huge population of locusts is multiplying in the humid American West, where a deep drought has created ideal conditions for locust eggs to hatch and survive into adulthood.

“I can only describe locusts in words,” said Richard Nicholson, a ranchers in Fort Klamath, a small community in southern Oregon who once remembered how gangs of locusts eat 1,000 acres a day and cover the ground like snow. The insects cause countless headaches for farmers and ranchers, compete with cattle for hard-to-find wild fodder, and cost tens of thousands of dollars in crop losses and costs. “You are a scourge of the earth… you are only destroying the land, destroying the crops. You’re just a bad, bad predator. “

Although productive, the locusts are not invaders. They are native to and have lived in western countries for millions of years, their populations usually in check. They hatch as tiny versions of adults, such that small ones about 50 can fit on a quarter-size coin. In average years, most die before they become the winged adults now buzzing in the rural sky. They and their eggs are vulnerable to pathogens, brutal winters, and starvation at a young age. But locust populations began to rise in the spring of 2020, thanks to warmer and drier winters that favored survival, along with some lucky rains that drive grass that feeds young locust populations.

Oregon and Montana have been hit hardest by the voracious eaters, particularly on the arid eastern flanks of both states. Thirteen other states are also facing locust damage, according to hazard maps from the US Department of Agriculture’s Animal and Phytosanitary Inspection Service. The program helps contain grasshoppers on pastureland and also targets a close cousin, the Mormon cricket. The 17 states under this pest patrol have a combined agricultural value of $ 8.7 billion, according to the latest estimates. Last year the program spent more than $ 5 million on the repression and is currently included in more.

Locusts in the Swan Lake area. Photo: Courtesy of Helmuth Rogg

“The country’s largest biomass consumer is not cattle, or bison. They’re locusts, ”said Helmuth Rogg, an entomologist and agronomist who works for the Oregon Department of Agriculture. “They eat and eat from the day they are born until they die. That’s all they do. “

“They basically ate all of the feed,” said John O’Keeffe, a ranchers whose ranch in eastern Oregon was besieged by locusts a year ago. The ranch was recently treated with insecticide to prevent further threats. O’Keeffe estimates that locusts cost him $ 50,000 in lost forage, plus the price of hay to feed the cattle once the pasture forage was gone.

Agricultural losses from locusts are often reported in the hundreds of thousands of dollars, according to Rogg. Not only do grasshoppers eat pasture forage, which also destroys forage for wild antelopes, but they also eat the leaves of fruit trees and nestle in the arid areas that ring crops, where they decimate crops by slowly eating inward. They are able to fly for miles, travel in ribbons to consume one area, and then move on to the next.

They eat and eat from the day they are born until they die. That’s all they doHelmuth Rogg

But controlling locusts can be a challenge. Because they molt like snakes and shed their skin as they grow, they are only susceptible to the most targeted insecticide, Dimilin, at a young age and between moults. That window of time is small in places like Oregon, where grasshoppers tend to hatch early and mature quickly, in part because the climate crisis is speeding up the time they hatch. Once discovered, adults are too old to suppress them except with chemicals that harm other insects. This means that ranchers and farmers who detect an infestation are often unlucky by the next year. This is already the case in Oregon, where the locusts are entering adulthood. Not so in Montana, where officials have made most of the insecticide applications.

Based on initial data, like the locust population, the campaign of repression will be the first or second largest in 35 years. Left alone, the locust population would eventually shrink. Their population outbreaks are usually cyclical and controlled after the predator populations catch up with them to tame them. In addition to the pathogens that claim them, parasites and fungi also attack grasshoppers, while beetles, moths, lizards and birds form the basis of food with their eggs. Their popularity as a prey base makes them the key to ecological balance most of the time. That is, until the density of population turns them into pests.

“They’re a nice beetle, like a pack, but if they walk through a field they’ll wipe out everything there,” said Tylor Lorenz, a sixth generation rancher near the Oregon-California border. “The damage they do when they come into the harvest is just terrible.”