Effects of Livestock Grazing on Grasshopper Abundance on a Native Rangeland in Montana

K. M. O'Neill¹, B. E. Olson², R. Wallander¹, M. G. Rolston² and C. E. Seibert³

Abstract
Livestock grazing can affect habitat quality for grasshoppers through effects on food and oviposition site availability, microclimate, and other factors. Because of this, some authors have suggested that grazing programs can be used to help manage pest grasshopper populations.

In a 6-yr study, we controlled access of cattle to replicated experimental plots on an Agropyron spicatum/Poa sandbergii pasture to create consistent year-to-year differences in postgrazing plant cover, with resultant affects on microclimate. After sampling grasshoppers multiple times after grazing treatments each summer, we found evidence of between-treatment differences in grasshopper abundance for the entire assemblage during 4 of the 6 yr.

Some species, including Melanoplus sanguinipes (perhaps the worse rangeland grasshopper pest in the western United States), tended to be more abundant on ungrazed plots, whereas Melanoplus gladstoni often had greater densities on heavily-grazed plots. The effect of grazing on grasshopper densities in this study was lower in magnitude and less consistent among years than in a study we conducted simultaneously at a nearby site where the vegetation was dominated by the exotic species crested wheatgrass (Agropyron cristatum).

Our results generally support proposals that grazing could be used to reduce pest grasshopper densities, although the effectiveness of a particular grazing scheme may vary among sites, years, and grasshopper and vegetation assemblages.

Source
Environmental Entomology (2010) 39: 775-786

Author Locations and Affiliations
(1) Department of Land Resources and Environmental Sciences, Montana State University, Bozeman, MT 59717
(2) Department of Animal and Range Sciences, Montana State University, Bozeman, MT 59717
(3) Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT 59717

Posted June 2010


	Organic Sci. Cluster	About Us	Top 10	Français
	British Columbia	Alberta	Saskatchewan	Manitoba
	Ontario	Québec	Atlantic	Donate
Research Extension Courses Consumers -------------------------- Virtual Tours Student & Job Opportunities News Articles Standards -------------------------- Market Information Events Issues Animal Welfare Strategic Plans -------------------------- Links Award-winners Site Map	Effects of Livestock Grazing on Grasshopper Abundance on a Native Rangeland in Montana K. M. O'Neill¹, B. E. Olson², R. Wallander¹, M. G. Rolston² and C. E. Seibert³ *Abstract* Livestock grazing can affect habitat quality for grasshoppers through effects on food and oviposition site availability, microclimate, and other factors. Because of this, some authors have suggested that grazing programs can be used to help manage pest grasshopper populations. In a 6-yr study, we controlled access of cattle to replicated experimental plots on an Agropyron spicatum/Poa sandbergii pasture to create consistent year-to-year differences in postgrazing plant cover, with resultant affects on microclimate. After sampling grasshoppers multiple times after grazing treatments each summer, we found evidence of between-treatment differences in grasshopper abundance for the entire assemblage during 4 of the 6 yr. Some species, including Melanoplus sanguinipes (perhaps the worse rangeland grasshopper pest in the western United States), tended to be more abundant on ungrazed plots, whereas Melanoplus gladstoni often had greater densities on heavily-grazed plots. The effect of grazing on grasshopper densities in this study was lower in magnitude and less consistent among years than in a study we conducted simultaneously at a nearby site where the vegetation was dominated by the exotic species crested wheatgrass (Agropyron cristatum). Our results generally support proposals that grazing could be used to reduce pest grasshopper densities, although the effectiveness of a particular grazing scheme may vary among sites, years, and grasshopper and vegetation assemblages. *Source* Environmental Entomology (2010) 39: 775-786 *Author Locations and Affiliations* (1) Department of Land Resources and Environmental Sciences, Montana State University, Bozeman, MT 59717 (2) Department of Animal and Range Sciences, Montana State University, Bozeman, MT 59717 (3) Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT 59717 Posted June 2010
Top

Effects of Livestock Grazing on Grasshopper Abundance on a Native Rangeland in Montana

Top