Protecting U.S. Rangeland from 

Grasshoppers and Mormon Crickets 

Rangeland in the Western United States is a valuable 

agricultural resource for livestock production and 

provides an important habitat for wildlife. Grasshoppers 

and Mormon crickets (referred to collectively as 

grasshoppers) are natural components of this 

ecosystem. However, their populations can reach 

outbreak levels and cause serious economic and 

ecological losses to rangeland forage, especially during 

periods of drought.

When a grasshopper outbreak threatens rangeland 

forage, Federal land management agencies, Native 

American tribes, State agriculture departments, 

county and local governments, private groups, and/

or individuals can request assistance from the U.S. 

Department of Agriculture’s (USDA) Animal and 

Plant Health Inspection Service (APHIS) to suppress 

rangeland grasshopper populations. 

Grasshoppers and Mormon 

Crickets

Grasshoppers and Mormon crickets are closely related 

insects that belong to the order Orthoptera. Nearly 

400 grasshopper species inhabit the Western United 

States, but only a small percentage are considered 

pest species. Anywhere from one to many grasshopper 

species can be found in a particular rangeland 

ecosystem, and economic damage usually occurs when 

pest grasshopper species increase in number. 

Grasshoppers are typically ground-dwelling insects 

with powerful hind legs that enable them to escape 

from threats by leaping vigorously. They are sometimes 

referred to as short-horned grasshoppers to distinguish 

them from katydids (bush crickets), which have much 

longer antennae. Mormon crickets (Anabrus simplex) 

are flightless, shield-backed katydids. Although they do 

not fly, Mormon crickets are highly mobile and capable 

of migrating great distances. They move in wide bands 

by walking or jumping, and may devour much of the 

forage in their path. 

Both insects damage grasses and other vegetation 

by consuming plant stems and leaves. Their feeding 

causes direct damage to plants’ growth and seed 

production. This reduces valuable livestock forage and 

can lead to other 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 crop plants is much higher than that of 

rangeland grasses. 

APHIS’ Grasshopper Program

APHIS surveys rangeland grasshopper 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. In addition, 

APHIS provides technical assistance on grasshopper 

management to landowners and managers, delivers 

public outreach and education programs, and may 

work with Federal and State agencies, tribes, and 

landowners to suppress grasshopper populations when 

direct intervention is necessary. 

APHIS treats grasshoppers only upon request 

and after determining that treatment is warranted. 

When a Federal land management agency, Native 

American tribe, State agriculture department, county 

or local government, private group, or individual with 

jurisdiction over the land makes a written request 

for grasshopper treatment, APHIS visits the site and 

assesses various factors to determine whether action 

is necessary. These factors include, but are not limited 

to, grasshopper densities per yard, the pest species 

and its biological stage, treatment timing and options, 

and other ecological considerations. County, State, and 

Federal officials, tribes, and/or rancher groups may also 

initiate cooperative local programs and request APHIS 

assistance when surveys show the potential for large 

grasshopper populations.

Cost Sharing for Grasshopper 

Suppression Treatments

Federal agencies own or manage approximately 

43 percent of U.S. rangeland. 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 are among the principal managers of the 

ANIMAL AND PLANT HEALTH INSPECTION SERVICE JULY 2016

PLANT PROTECTION AND QUARANTINE 
rangeland. Federal rangeland eligible for cooperative 

grasshopper suppression treatments from APHIS 

includes: areas with widespread outbreaks; areas with 

developing or incipient populations of grasshoppers, 

that, if treated, would prevent a wider spread of 

outbreaks; and Federal or Trust land borders that, if 

treated, would prevent the movement of economically 

threatening populations of grasshoppers to adjacent 

private agricultural lands. 

APHIS shares the costs of providing grasshopper 

suppression treatments on Federal, State, and private 

rangeland as directed by the Plant Protection Act. On 

Federal and tribal Trust lands, APHIS pays 

100 percent of the treatment cost. On State lands, 

APHIS provides 50 percent of the funds for treatment 

and control. On private rangelands, APHIS provides 

33 percent of the funding, with the State and/

or private landowner responsible for paying the 

remainder of the treatment cost. This cost share is 

only available if APHIS conducts the suppression 

treatments. 

APHIS does not have the authority to conduct 

grasshopper suppression programs on private 

crop lands. However, APHIS conducts rangeland 

treatments in areas where federally administered 

rangeland is immediately adjacent to crops. This not 

only protects the rangeland forage, but also prevents 

grasshoppers from moving into the adjacent crops. 

In these situations, APHIS does not treat the crop 

land, only the adjacent rangeland; the crop owner is 

responsible for any crop land treatments that may be 

needed. In addition, if small amounts of croplands 

(typically less than 10 percent of the treatment area) 

are interspersed in a rangeland treatment block, 

APHIS could treat the entire block in order to maintain 

the continuity of the spray program. 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 crop land. 

Treatment Options

In 2002, APHIS completed the Rangeland 

Grasshopper and Mormon Cricket Suppression 

Program Final Environmental Impact Statement (EIS). 

The EIS considered three alternatives for managing 

grasshopper/Mormon cricket populations. The 

alternatives were: no APHIS control action; insecticide 

applications at conventional rates and complete 

area coverage; and reduced agent area treatments 

(RAATs), an approach that treats less land area and 

uses insecticides at lower rates. The RAAT strategy 

relies on an insecticide’s ability to suppress 

grasshoppers within treated swaths—and the natural 

movement of grasshoppers into the treated swath as 

they forage—while conserving grasshopper predators 

and parasites in alternating untreated areas. 

APHIS uses three insecticides in its grasshopper 

program: carbaryl, diflubenzuron, and malathion. 

Treatment consists of a single application of only 

one of these three. Each insecticide is currently 

registered for use and labeled by the U.S. 

Environmental Protection Agency for control of 

rangeland grasshoppers. The insecticide APHIS 

chooses depends on a number of factors, including: 

infestation size; grasshopper species; population 

age; climate; weather; forage condition; economics; 

and environmental risks. Each insecticide is very 

effective and safe when properly used under the 

right conditions. In addition, APHIS conducts 

environmental assessments in each State before 

any actions occur. APHIS follows all insecticide label 

directions, along with conditions outlined in the EIS, 

the environmental assessment, grasshopper program 

guidelines, and the original treatment request letter. 

Additional Information

For additional information on APHIS’ grasshopper 

program, please visit the APHIS Web site at http://

www.aphis.usda.gov/plant-health/grasshopper, or 

contact your State Plant Health Director (SPHD). 

You can find contact information for your SPHD 

on APHIS’ Web site at http://www.aphis.usda.gov/

planthealth/sphd.

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opportunity provider, 

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