Earth Protect Blog

BILLINGS, MONT. » A punishing drought in the West is drying up waterways, sparking wildfires and leaving farmers scrambling for water. Next up: a plague of voracious grasshoppers.

Federal agriculture officials are launching what could become their largest grasshopper-killing campaign since the 1980s amid an outbreak of the drought-loving insects that cattle ranchers fear will strip bare public and private rangelands.

In central Montana’s Phillips County, more than 50 miles from the nearest town, Frank Wiederrick said large numbers of grasshoppers started showing up on prairie surrounding his ranch in recent days. They’re beginning to denude trees around his house.

“They’re everywhere,” Wiederrick said. “Drought and grasshoppers go together and they are cleaning us out.”

To blunt the grasshoppers’ economic damage, the U.S. Department of Agriculture this week began aerial spraying of the pesticide diflubenzuron to kill grasshopper nymphs before they develop into adults. Approximately 3,000 square miles in Montana are expected to be sprayed, twice the size of Rhode Island.

Agriculture officials had seen this year’s infestation coming, after a 2020 survey found dense concentrations of adult grasshoppers across about 55,000 square miles in the West. A 2021 grasshopper “hazard map” shows densities of at least 15 insects per square yard in large areas of Montana, Wyoming and Oregon and portions of Idaho, Arizona, Colorado and Nebraska.

Left unaddressed, federal officials said the agricultural damage could become so severe it could drive up beef and crop prices.

The program’s scale has alarmed environmentalists who say widespread spraying will kill numerous insects, including spiders and other grasshopper predators as well as struggling species such as monarch butterflies. They’re also concerned the pesticides could ruin nearby organic farms.

Government officials say they will spray pesticides in low concentrations and spray a strip of rangeland, then skip the next strip. The intent is to kill grasshoppers passing between strips while sparing other insects that don’t move as far. — The Associated Press BBB

Grasshoppers thrive in warm, dry weather, and populations were up last year, setting the stage for an even bigger outbreak in 2021. U.S. Department of Agriculture's Animal and Plant Health Inspection Service via The Associated Press