Voracious Grasshoppers Threaten Western Rangeland and Crops

Daniel Munch

Economist

When learning U.S. history, narratives of vast swarms of locusts ravaging millions of acres of farmland are often recounted. Not all grasshoppers are locusts, and the swarms aren't quite as big as they were in the 1800s, but grasshoppers and Mormon crickets remain a persistent risk to agriculture in the West, inflicting significant damage to rangeland used for grazing and crops.

Almost 400 native species of grasshoppers inhabit the Western United States, though only a small fraction (about 12 species) are considered pests. Grasshoppers compete with cattle and other herbivores (including wildlife like deer and elk) for forage and are more likely to become a threat in areas with less than 30 inches of rainfall annually. They can consume up to 50% of their body weight each day in forage (while cattle consume 1.5-2.5% of their body weight). Put differently, just 30 pounds of grasshoppers will eat as much as a 600-pound steer raised for beef in a day. Grasshoppers are an even bigger menace to crop farmers and ranchers on public and private lands when drought conditions are added to the mix.

Grasshopper and cricket outbreaks not only result in the physical destruction of forage and crops but also contribute to soil erosion and degradation, disrupt rangeland nutrient cycles and impede rangeland water filtration, which can have lasting impacts on rangeland ecosystems. Western landowners face heightened risks from grasshoppers due to the substantial amount of federally owned land in the region. Pest infestations on federal lands reduce the quantity and quality of forage available for those with public lands grazing leases. In the absence of grasshopper and cricket management on federal lands, insects can migrate onto private lands, undermining the effectiveness of common private pest management efforts. This movement from public to private lands complicates the control of these pests.

Continued coordination and efforts among the federal government, states and private landowners is essential to safeguarding the livelihoods of farmers and ranchers against these small but hungry pests.

Literature on current economic impacts of grasshoppers on agriculture is limited. Generally, monetary losses either fall under the value of crops or rangeland consumed by insects that could no longer be sold on the market or consumed by livestock to produce meat or wool and the cost to treat populations that have reached pest-concern levels. Some of the best available data comes from county agricultural commissioner disaster reports in California that indicate more than $52 million in losses in a single county in one year.

A recent Market Intel analysis only scratches the surface in terms of describing these economic damages due to the limited data available and isolated surveying. Efforts to manage and mitigate grasshopper populations, led by USDA's Animal and Plant Health Inspection Service through the Rangeland Grasshopper and Mormon Cricket Suppression Program, involve sophisticated monitoring and targeted treatments. Continued coordination and efforts among the federal government, states and private landowners is essential to safeguarding the livelihoods of farmers and ranchers against these small but hungry pests.

Daniel Munch is an economist at the American Farm Bureau Federation.