ARS Grasshopper Publications

An Overview of Grasshopper Management Research
at USDA-ARS Northern Plains Agricultural Research Laboratory

GRASSHOPPER ECOLOGY & MANAGEMENT

Rationale: Grasshoppers play an important role in North American grassland ecosystems, serving as food for wildlife and contributing to nutrient cycling. However, periodic grasshopper outbreaks on rangeland can result in competition with other herbivores for vegetation and lead to grasshopper dispersal into crops. Of the 400 species of grasshoppers in the Western United States, fewer than 2 dozen are capable of causing significant economic damage to crops and forage. In the past, pesticide application has been the main tool used to combat grasshopper outbreaks on rangeland. Due to increased environmental concerns and economic costs associated with pesticide use, we are currently investigating ecologically-based approaches to grasshopper management. Very little research has examined preventative strategies that reduce the likelihood or intensity of grasshopper outbreaks. Developing ways to prevent grasshopper outbreaks requires that we understand the ecological interactions underlying these outbreaks and can manipulate them accordingly. Certain types of grazing or habitat management may create unfavorable habitats for grasshoppers or spur increases in naturally occurring grasshopper diseases and predators. In addition, microbial products may provide environmentally-benign management options when warranted.

 

Contributing Scientists: David Branson, Stefan Jaronski & Greg Sword

 

Goal:

• To understand the ecological processes underlying grasshopper outbreaks.

• To develop sustainable and affordable grasshopper management that incorporates ecological processes to reduce grasshopper outbreaks, while improving or maintaining the condition of rangeland.

• To evaluate new microbial controls and new technologies for existing microbial agents to manage grasshopper outbreaks.

 

For more information, visit the pages of the contributing scientists listed above.

MORMON CRICKET ECOLOGY

Rationale:  Outbreaks of the Mormon cricket, Anabrus simplex (Orthoptera; Tettigoniidae), once again threaten large parts of the western US. Mormon cricket outbreaks originate on rangeland and can lead to the formation of huge migratory bands that move into and damage crop systems. At NPARL scientists are working as part of an international collaborative effort to examine Mormon cricket migratory behavior as a means to ultimately predict migratory band movement patterns. Predictive models of migratory band movement will help to fine-tune existing management practices, thereby reducing the cost, manpower, and undesirable non-target effects associated with chemical control operations. This work also serves as an important component of a broader research endeavor to understand the generality of behavioral mechanisms underlying collective movement in other animal groups such as migratory locusts.

Mormon cricket movement is being investigated at three different spatial scales using a combination of laboratory and field experiments. The results of multiple analyses conducted across spatial scales will be integrated to generate models of group movement patterns at the landscape scale. Laboratory analyses are being conducted using a computer-based video tracking system to quantify individual movement behaviors and their interactions with other insects. Intermediate scale analyses are planned using a related video analysis technique to simultaneously quantify the movement and social interactions of hundreds of individuals simultaneously as they march in naturally-occurring bands. At the landscape scale, radiotelemetry is being employed to track the long distance movements of individual Mormon crickets as they travel in within bands. Movement data from the field are then correlated with local topographic and weather variables to identify environmental cues that affect the direction, distance and speed of migratory band movement. These results, in conjunction with knowledge of the behavioral mechanisms underlying band formation and movement, will be used to develop models of band movement.
 

Contributing Scientists: Greg Sword
 

Collaborators: Pat Lorch (University of North Carolina, Chapel Hill), Darryl Gwynne (University of Toronto at Mississauga), Stephen Simpson (University of Oxford), Iain Couzin (University of Oxford/Princeton) and David Sumpter (University of Oxford).

Goals:

• To determine if Mormon crickets expresses locust-like density-dependent phase polyphenism.
• To understand the environmental cues that mediate Mormon cricket migratory band formation and movement patterns.
• To develop predictive models of Mormon cricket migratory band movement.

Rangeland Insect Laboratory Publications, 1918 to 1996

Complete bibliography of research publications produced by the USDA-ARS Rangeland Insect Laboratory in Bozeman Montana. The Rangeland Insect Laboratory was located at Bozeman, MT, for over 65 years and was incorporated into the Northern Plains Agricultural Research Lab in Sidney, MT in 1996. Copies of individual articles can be requested by contacting USDA-ARS Northern Plains Agricultural Research Lab, Grasshopper Reprint Requests, 1500 N. Central Ave., Sidney, MT 59270.

USDA-ARS Grasshopper Publications, 1996 to Present