Featured Research

from universities, journals, and other organizations

Clues about grasshopper population explosions

Date:
February 27, 2011
Source:
University of Notre Dame
Summary:
Biologists are examining what can limit grasshopper populations and the role played by grasshoppers in prairie ecosystems.

Grasshopper. Grasshoppers and Mormon crickets cause an estimated $1.5 billion (2005 U.S. dollars) in damage to grazing lands in the American West.
Credit: iStockphoto/Christian Uhrig

Literature and films have left us with vivid images of the grasshopper plagues that devastated the Great Plains in the 1870s. Although commonly referred to as grasshoppers, the infestations were actually by Rocky Mountain locusts.

Related Articles


The Rocky Mountain locust became extinct in 1902, but their cousins, grasshoppers and Mormon crickets, today still cause an estimated $1.5 billion (2005 U.S. dollars) in damage to grazing lands in the American West. A long-running research project directed by University of Notre Dame biologist Gary Belovsky, who also is director of the Notre Dame Environmental Research Center (UNDERC), is examining what limits grasshopper populations and the role played by grasshoppers in prairie ecosystems.

Belovsky first started studying grasshopper populations in 1978 at the National Bison Range, now a location for one of UNDERC's national undergraduate programs. Following the last major Western grasshopper outbreak in 1985, the U.S. Department of Agriculture's Animal and Plant Health Inspection Service (UDSA-APHIS) asked Belovsky to help study the grasshopper's feeding preferences and population dynamics in western Montana.

Belovsky's research demonstrates that no single factor leads to a grasshopper outbreak, but, rather, multiple interacting factors are necessary. This requires sound understanding of how food and predators influence these native insects in combination with varying climate.

One of his key discoveries is that grasshoppers have a major impact on plants by changing the way nitrogen cycles in grasslands. Where grasshoppers speed up the process of nitrogen recycling by selectively feeding on plants that take longer to decompose, plant production increases. However, if they selectively feed on plants that decompose quickly, nitrogen becomes less available to the soil and plant production decreases.

Belovsky's findings helped change the way USDA/APHIS carries out its mandate to control grasshoppers on federal rangeland. Previously, the agency sprayed large swaths of land with insecticides, including areas where grasshoppers were actually befitting plant growth by speeding up nitrogen recycling. USDA/APHIS now relies on more restricted spraying, focusing on those areas where grasshoppers are damaging plants.

Belovsky also used National Science Foundation funding to develop mathematical models to help predict significant spikes in grasshopper populations based on the number of grasshopper eggs. If egg numbers are low in the spring, grasshopper predators like birds and spiders can usually keep the populations under control. However, when eggs in the spring are especially numerous, more grasshoppers hatch and predators are unable to keep the populations under control, which can signal significant problems for rangeland ecosystems. However, if grasshoppers are very abundant, the young grasshoppers may actually compete for the rarer highly nutritious food plants and starve to death before they can grow up and cause damage to the range.

Belovsky's research is now the longest running experimental study at a site examining what controls grasshopper numbers and, as such, Belovsky continues to acquire an unusually detailed and rich database of scientific information about Western rangelands. Additionally, UNDERC undergraduates, including a number of Native Americans, learn about this striking ecosystem and some participate in the research.

His research has the potential to make grasshopper plagues, like the Rocky Mountain locust, but a memory.


Story Source:

The above story is based on materials provided by University of Notre Dame. Note: Materials may be edited for content and length.


Cite This Page:

University of Notre Dame. "Clues about grasshopper population explosions." ScienceDaily. ScienceDaily, 27 February 2011. <www.sciencedaily.com/releases/2011/02/110225142832.htm>.
University of Notre Dame. (2011, February 27). Clues about grasshopper population explosions. ScienceDaily. Retrieved November 28, 2014 from www.sciencedaily.com/releases/2011/02/110225142832.htm
University of Notre Dame. "Clues about grasshopper population explosions." ScienceDaily. www.sciencedaily.com/releases/2011/02/110225142832.htm (accessed November 28, 2014).

Share This


More From ScienceDaily



More Plants & Animals News

Friday, November 28, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Research on Bats Could Help Develop Drugs Against Ebola

Research on Bats Could Help Develop Drugs Against Ebola

AFP (Nov. 28, 2014) In Africa's only biosafety level 4 laboratory, scientists have been carrying out experiments on bats to understand how virus like Ebola are being transmitted, and how some of them resist to it. Duration: 01:18 Video provided by AFP
Powered by NewsLook.com
New Dinosaur Species Found in Museum Collection

New Dinosaur Species Found in Museum Collection

Reuters - Innovations Video Online (Nov. 27, 2014) A British palaeontologist has discovered a new species of dinosaur while studying fossils in a Canadian museum. Pentaceratops aquilonius was related to Triceratops and lived at the end of the Cretaceous Period, around 75 million years ago. Jim Drury has more. Video provided by Reuters
Powered by NewsLook.com
Tryptophan Isn't Making You Sleepy On Thanksgiving

Tryptophan Isn't Making You Sleepy On Thanksgiving

Newsy (Nov. 27, 2014) Tryptophan, a chemical found naturally in turkey meat, gets blamed for sleepiness after Thanksgiving meals. But science points to other culprits. Video provided by Newsy
Powered by NewsLook.com
Classic Hollywood Memorabilia Goes Under the Hammer

Classic Hollywood Memorabilia Goes Under the Hammer

Reuters - Entertainment Video Online (Nov. 26, 2014) The iconic piano from "Casablanca" and the Cowardly Lion suit from "The Wizard of Oz" fetch millions at auction. Sara Hemrajani reports. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins