The USDA reports that there are nearly 400 grasshopper species that inhabit the Western United States, but only about 12 are considered pests. But those that are deemed pests, along with their close cousins the Mormon cricket, do significant damage to rangeland and crops in the Central and Western United States every year.
“The biggest biomass consumers in the country are not cattle, are not bison. They are grasshoppers,” says Helmuth Rogg, an entomologist and agricultural scientist who works for the Oregon Department of Agriculture. “They eat and eat from the day they get born until the day they die. That’s all they do.”
Grasshoppers lay eggs in the fall and begin hatching by summer. They particularly like to eat hay and grasses — such as alfalfa — which many ranchers grow to feed their cattle.
In addition to grazing down rangeland forage, which also wipes out feed for wild antelope, grasshoppers eat the leaves off of fruit trees and bed down in the dry areas ringing crops, where they decimate grain by eating slowly inward. The pests are also capable of traveling for miles and do so in large bands that can quickly consume an entire area, before moving on to the next.
Grasshoppers and Mormon crickets consume $1.7 billion of forage annually in the US, according to the USDA. However, analysis by the American Farm Bureau points out that literature on current economic impacts of grasshoppers on agriculture is limited, so the real costs are likely higher. Still, Farm Bureau points out that this level of harm is detrimental to farms already operating on razor thin margins. It is also a burden on the crop insurance system.
The USDA every year releases a “Grasshopper Hazard Forecast” based on prior-year adult grasshopper densities. The most recent, released in October 2023, predicted that much of Central and Eastern Montana would see a large density of grasshoppers this year. That forecast may not bear out, however, thanks to some well-timed rainfall that may have caught the grasshoppers right at hatching time in late May and June, according to local experts. Fingers crossed that the luck holds. Montana pastures for the last three summers have been repeatedly devastated by grasshoppers, forcing ranchers to either buy expensive feed or sell off cattle.
Controlling grasshoppers is another challenge altogether. Because they molt (shed skins as they grow), they are only susceptible to targeted insecticides when young and between molts. Once they are adults, the only chemicals that work against them tend to also be harmful to other insects and the environment.
One way farmers and ranchers can help themselves is by taking advantage of the “Rangeland Grasshopper and Mormon Cricket Suppression Program.” Administered by the USDA’s Animal and Plant Health Inspection Service (APHIS), the program offers treatments for federal, state, and private rangelands through a cost-share model within APHIS.
According to AFBF, between 2019 and 2023 APHIS protected over 3.33 million acres across eight Western states, with 2.8 million acres treated for grasshopper control and 482,000 acres treated for Mormon crickets. This corresponded to $5.68 million in program treatment expenditures.
AFBF says it’s important to note that APHIS is unable to conduct suppression programs for grasshoppers and Mormon crickets on private croplands. However, they do perform rangeland suppression treatments in areas where federally managed rangeland is directly adjacent to private croplands. Learn more about the program HERE.