Reducing Grasshopper Outbreaks Through Habitat Manipulation Tactics

Grasshoppers contribute significantly to grassland function, but periodically exhibit both local and large-scale outbreaks resulting in large scale chemical control. There are many reasons to believe that approaches to grasshopper management that aim to reduce or prevent outbreaks are possible. These habitat manipulation tactics maintain existing ecological feedbacks responsible for sustaining populations at economically nonthreatening levels. Sustainable strategies to minimize the likelihood and extent of grasshopper outbreaks while limiting the need for chemical intervention are a rational and attainable goal for managing grasslands as renewable resources.

Sustainable Management of Insect Herbivores in Grassland Ecosystems: New Perspectives in Grasshopper Control (pdf)

 Livestock Grazing and Grasshopper Outbreaks: Management Options to Reduce Grasshopper Outbreaks

Suppression of Grasshoppers in the Great Plains Through Grazing Management  
An article describing 6-year study showing that twice-over rotational grazing mitigated a grasshopper outbreak. Grasshoppers averaged 3.3X higher under season-long grazing than under rotational grazing over the 6-year study. Local outbreaks under season-long grazing in 1997 and 1998, did not occur under rotational grazing. The study illustrates that preventative grasshopper management through grazing management may be practical in the northern Great Plains.

IPM Handbook:

• The Importance of Grazing Strategies to Grasshopper Management: An Introduction
• Grazing Effects on Grasshopper Populations in Southern Idaho
• Beneficial Changes of Rangeland Through Proper Grazing
• Grasshopper Habitat Manipulation

David Branson's homepage at USDA-ARS-NPARL describes research being conducted on the use of grazing management to reduce grasshopper outbreaks.

 Chemical Control Methods (RAATs)

Reduced Area and Agent Treatments (RAATs) to control grasshopper infestations
A chemical control method where the rate of insecticide is reduced, and untreated swaths are alternated with treated swaths. RAATs reduces costs by more than 50 percent while maintaining effectiveness and reducing environmental impact. RAATs techniques have been developed for both aerial and ATV ground- based applications using diflubenzuron (Dimilin 2L), carbaryl (Sevin XLR) and  malathion (Fyfanon).

• Aerial Reduced Area and Agent Treatment Strategies
• Ground-Applied Reduced Area and Agent Treatment Strategies

 Practical Grasshopper Management and IPM  Information for Western U.S. States and Canadian Provinces

Included are links to numerous resources, informational guides and management publications from state Cooperative Extension Services, universities and departments of agriculture on the management of grasshoppers affecting both crops and rangeland. Includes information on controlling grasshoppers in cropland, rangeland, and yards and gardens.

Environmental Side Effects of Grasshopper Control: Nontarget Effects and Ecotoxicology Information

Grasshopper chemical control sprays blanket the rangeland habitat and expose nontarget animal life to the chemicals. Though the insecticide spray programs reduce grasshopper densities in the short term, effects on nontarget species and rangeland ecology need to be evaluated. Investigations described in this section examine the complex ecological impacts of grasshopper control on nontarget life.

 Grasshopper and Mormon Cricket Control Programs on Western U.S. Rangelands (USDA-APHIS-PPQ)

Rangeland Grasshopper and Mormon Cricket Suppression Program,  Final Environmental Impact Statement--2002 (pdf)

Record of Decision, Rangeland Grasshopper and Mormon Cricket Suppression Program, Final Environmental Impact Statement--2002 (pdf)

Grasshopper Guidebook Provisional (January 2008)

Grasshopper Ecology: Nontechnical Information for Managers

Understanding the ecological processes and events that produce outbreaks is necessary for pest managers to be able to forecast outbreak events and design better management strategies. The information in this section describes relationships between grasshoppers and vegetation, grasshopper outbreaks and weather patterns, habitat manipulation to reduce grasshopper outbreaks, population regulation in grasshoppers and grasshopper outbreaks. This section summarizes ecological insights relevant to integrated pest management (IPM) activities on rangeland.

 Grasshopper Management Research Information and Publications from USDA-ARS Northern Plains Agricultural Research Laboratory (NPARL)

The goals of USDA-ARS grasshopper research are to understand the ecological processes underlying grasshopper outbreaks, and to develop sustainable and affordable grasshopper management that incorporates ecological processes to reduce grasshopper outbreaks while improving or maintaining the condition of rangeland.

 Integrated Pest Management and Chemical Control Research Reports

North Dakota Integrated Pest Management Demonstration Project
A project conducted to compare IPM and standard chemical control programs, determine the effectiveness of early sampling to detect grasshopper infestations, examine long-term grasshopper responses to treatments, and evaluate control techniques with lower non-target impacts.

3-Year South Dakota RAATs Demonstration Project
A study conducted from 1997 to 1999 to demonstrate on a large scale, the utility of reduced area and agent treatments (RAATs) for reducing costs to manage damaging populations of grasshoppers.

Impacts of Rangeland Grasshopper Insecticide Treatments on Biological Control Agents (Apthona) of Leafy Spurge, Euphorbia esula L in Western North Dakota. By R. Nelson Foster et al. (PDF, 1.6 MB)
Established populations of introduced Aphthona spp. on leafy spurge may be in jeopardy on western rangelands where populations of grasshoppers require insecticide treatments. Laboratory and field evaluations were conducted to determine the impacts of 8 grasshopper control treatments on two biocontrol agents.

Cultural Control Methods for Farmers

Grasshopper Management Guide (Alberta) (PDF)
Includes information on grasshopper cultural control methods to protect cropland and the effects of weather and natural enemies on grasshopper outbreaks.

Grasshopper Management - Pest Management Technical Note
From ATTRA--National Sustainable Agriculture Information Service. Outlines non-chemical strategies available for management of grasshoppers in crop systems.

 Sampling Grasshoppers: How to determine if they are an economic problem

Assessing Rangeland Grasshopper Populations (IPM Handbook)
Land managers need accurate methods for assessment of rangeland grasshopper populations to make appropriate management decisions. This chapter explores techniques and issues related to sampling and surveying rangeland grasshoppers.

Grasshopper Survey Section of Pfadt's Field Guide

Seasonal Occurrence of Common Western North Dakota Grasshoppers (IPM Handbook)

How to Scout for Pest and Non Pest Grasshoppers in the Canadian Prairies (PDF) by Dan L. Johnson from the 2004 issue of Grainmagazine, Diseases, Insects & Weeds 32-33.
Not all grasshoppers are pests, and it helps to distinguish them to reduce insecticide use. Includes descriptions of the main non-pest species that you might encounter while scouting in the spring for the more devastating kind.

Please check the “What’s New” section of this web site for updates on new research and management information.