Protecting U.S. Rangeland From Grasshoppers and Mormon Crickets 

Rangelands in the Western United States are valuable 

agricultural resources for livestock production and provide 

essential wildlife ecosystems. Grasshoppers and Mormon 

crickets are native insects found in rangelands; however,

their populations periodically reach outbreak levels and 

cause economic and ecological losses to rangeland forage 

necessary for feeding livestock and wildlife, especially 

during periods of drought. Nearly 400 grasshopper species 

inhabit the Western United States, but only a small 

number of them (12 species, in particular) are considered 

pests, with varying numbers and combinations of species 

found in each rangeland ecosystem. The Mormon cricket 

(Anabrus simplex) is the only katydid species known to 

reach outbreak-level populations in the United States. 

When outbreaks of these pests threaten rangeland 

forage, you can request help from the U.S. Department 

of Agriculture (USDA) to suppress their populations.

Grasshoppers and Mormon Crickets

Grasshoppers and Mormon crickets belong to the insect 

order Orthoptera. Rangeland grasshoppers are grounddwelling insects with powerful hind legs that enable them 

to escape from threats by leaping vigorously. Most 

species also have wings that allow them to fly relatively 

long distances. They are sometimes referred to as “shorthorned” grasshoppers to distinguish them from katydids 

with much longer antennae (such as Mormon crickets, 

which are flightless, shield-backed katydids). Although 

they do not fly, Mormon crickets walk or jump in large 

groups made up of millions or billions of individual insects 

and can migrate great distances. 

Both grasshoppers and Mormon crickets damage grasses 

and other vegetation by consuming plant stems and 

leaves, harming plant growth and seed production. This 

reduces valuable livestock forage and can lead to other 

environmental effects, including soil erosion and 

degradation, disruption of rangeland nutrient cycles, 

interference with rangeland water filtration, and 

potentially irreversible changes in the rangeland 

ecosystem. In addition, some populations that develop 

on rangelands can invade adjacent cropland where the 

value of traditional crop plants is often much higher than 

that of rangeland grasses. 

USDA Rangeland Grasshopper and Mormon 

Cricket Suppression Program 

Through the Rangeland Grasshopper and Mormon Cricket 

Suppression Program, USDA’s Animal and Plant Health 

Inspection Service (APHIS) surveys rangeland grasshopper 

and Mormon cricket populations in 17 Western States: 

Arizona, California, Colorado, Idaho, Kansas, Montana, 

Nebraska, Nevada, New Mexico, North Dakota, 

Oklahoma, Oregon, South Dakota, Texas, Utah, 

Washington, and Wyoming. We also provide technical 

assistance to landowners and managers, deliver public 

outreach programs, and may work with landowners and 

managers to suppress grasshopper populations when 

direct intervention is needed. 

Adult male grasshopper (Melanopus sanguinipes); this species is considered to be Mormon cricket (Anabrus simplex) 

one of the most damaging rangeland grasshoppers. 
USDA is an equal opportunity provider, employer, and lender. APHIS 81-35-033 | Issued August 2021

APHIS only treats grasshoppers or Mormon crickets upon 

written request of the landowner and after assessing

several factors to determine if treatment will be effective.

These factors include, but are not limited to, grasshopper 

and Mormon cricket densities per square yard, the pest 

species and its life stage, treatment timing and options, 

and other ecological considerations. Landowners may 

also start cooperative local programs and request our 

assistance when surveys show the potential for large 

grasshopper or Mormon cricket populations.

Cost Sharing for Suppression Treatments

Federal agencies own or manage approximately 

43 percent of U.S. rangeland. The principal managers 

of these rangelands include the U.S. Department of the 

Interior’s Bureau of Land Management, the Bureau of 

Indian Affairs or individual Tribes, and USDA’s Forest 

Service. Federal rangelands eligible for cooperative 

grasshopper or Mormon cricket suppression treatments 

from APHIS include areas with: widespread outbreaks 

in progress; developing or incipient populations of 

grasshoppers or Mormon crickets, that, if treated, 

would prevent wider outbreaks; and Federal or Trust 

land borders that, if treated, would prevent economically 

threatening populations of grasshoppers and Mormon 

crickets from moving to adjacent private agricultural lands.

When funding is available, APHIS shares the costs of 

providing suppression treatments on rangelands, per

Section 7717 of the Plant Protection Act. On Federal and 

Tribal Trust rangelands, we pay 100 percent of treatment 

costs. On State lands, we provide 50 percent of the 

treatments costs and the State provides the remaining 

funds. On private lands, we cover 33 percent of the 

treatment costs, with the State and/or private landowner 

responsible for the remainder. Cost shares are only 

available if APHIS conducts the treatments. 

APHIS does not have the authority to conduct 

grasshopper suppression treatments on private 

croplands. However, we conduct rangeland suppression 

treatments in areas where federally managed rangeland 

is immediately adjacent to private croplands. This 

protects rangeland forage and prevents grasshoppers 

and Mormon crickets from moving into adjacent crops. 

In these circumstances, APHIS only treats the adjacent 

rangeland, and the crop owner is responsible for treating 

their croplands, if desired. If small amounts of croplands 

(typically less than 10 percent of the treatment area) are 

interspersed in a rangeland treatment area, we might 

treat the entire area to maintain the continuity of the 

treatments. The insecticide, however, must be labeled 

for use on that crop. In such cases, the private landowner 

would pay 100 percent of the cost for treatments 

conducted on their cropland.

Treatment Options 

In 2019, APHIS updated the Rangeland Grasshopper and 

Mormon Cricket Suppression Program Final 

Environmental Impact Statement (EIS). The EIS evaluates

three options for suppressing grasshopper and Mormon 

cricket populations in Western States. This document is 

available on the APHIS website at www.aphis.usda.gov

(search for “grasshopper EIS”). 

APHIS’ preferred suppression option is using reduced 

agent area treatments (RAATs). This option treats less 

land area overall and uses insecticides at lower rates and 

volumes. RAATs alternate between treating and skipping 

(untreated) swaths of rangeland. Skipped swaths often 

total 50 percent or more of a given area. In this scenario, 

the insecticide suppresses grasshopper or Mormon cricket 

populations in the treated swaths while conserving their 

predators and parasites, as well as other nontarget 

arthropods, in the skipped swaths. 

We have the option to use four insecticides in our

grasshopper program: carbaryl, diflubenzuron, malathion, 

and chlorantraniliprole. A suppression treatment consists 

of a single application in a given year of one of these 

insecticides. Each insecticide is registered for use and 

labeled by the U.S. Environmental Protection Agency 

(EPA) for sufficient management of rangeland 

grasshoppers. The insecticide APHIS chooses depends 

on several factors, including outbreak density, species, 

population age, climate, weather, forage conditions, 

economics, and environmental risks.

Each insecticide is very effective and safe for people, 

animals, and the environment when properly applied. 

We conduct and post public environmental assessments 

in each State before taking any actions. We follow all 

insecticide label directions, along with conditions outlined 

in the EIS, the environmental assessments, program 

guidelines, and the treatment request letter.

More Information

Learn more about APHIS’ Rangeland Grasshopper and 

Mormon Cricket Suppression Program on our website 

or contact your State Plant Health Director

(www.aphis.usda.gov/planthealth/sphd).