Featured Research

from universities, journals, and other organizations

Corn Borer Damage Can Be Halved By Releasing Army Of Wasps Early And Just Once, Says Cornell Research Report

Date:
November 20, 2000
Source:
Cornell University
Summary:
In a war against the European corn borer, a major pest of sweet corn, Cornell University scientists have found that an army of tiny wasps, released just once and early in the season, can reduce damage to ears of corn by half.

ITHACA, N.Y. -- In a war against the European corn borer, a major pest of sweet corn, Cornell University scientists have found that an army of tiny wasps, released just once and early in the season, can reduce damage to ears of corn by half.

For sweet corn producers in New York and several other Northeastern and Midwestern states this is "potentially big news," says Michael Hoffmann, Cornell associate professor of entomology and director of the university's New York State Integrated Pest Management program. In field tests in which wasps were released, Hoffmann says, 6 percent of ears on average were damaged, compared with 12 percent in fields in which wasps were not released.

Details of the test are described in "Biological Control of European Corn Borer with Inoculative Releases of Trichogramma ostriniae ," authored by Hoffmann; Mark Wright, Cornell research associate in entomology; Thomas Kuhar, Cornell postdoctoral researcher in entomology; and Sylvie Chenus, entomology technician. The article will be submitted to the Journal of Biological Control .

The European corn borer attacks field and sweet corn, costing American farmers about $1 billion annually in damage and control expenses. The pest first arrived in the United States in the 1920s.

Cornell scientists have found that by releasing an army of tiny, beneficial T. ostriniae wasps early enough in the sweet corn growing season, the borers can be greatly suppressed without additional wasp releases or insecticide applications. However, the grower can spray insecticide again if necessary, and a portion of the wasps will survive and continue to help control the borers.

Typically, these wasps are released throughout the summer growing season in large numbers. But the new research shows that this is unnecessary. The scientists found that only one early release was needed -- when the sweet corn is knee-high. And growers do not need many wasps -- about 30,000 per acre. The total cost, including packaging and placement in the field, is less than a single application of insecticide. The Cornell scientists conducted their field research in Tompkins, Tioga, Cayuga and Broome counties in New York.

As late-stage larvae, borers overwinter in corn stalks. By late spring, the larvae pupate and become adults -- corn borer moths -- and begin laying eggs. Within a few days the eggs become larvae and begin attacking the corn. The corn borer can tunnel through the stalk and destroy the plant's vascular system. When the wasps are introduced to the cornfield, the tiny females insert their eggs into corn borer eggs, effectively killing off the borer embryo. In time, two or more wasps emerge from each borer egg. As another cycle of wasps emerges, the female wasps seek out yet more borer eggs and repeat the process.

"The developing borer is killed and does not have a chance to damage the corn," says Hoffmann. "The wasp is strictly an egg parasitoid and it searches for more corn borer eggs. We found 50 percent less damage to sweet corn fields where the wasps were released compared to the control fields."

In upstate New York, the beneficial wasps do not overwinter and growers have to inoculate their fields every season. "We were hoping they would overwinter and become permanent residents in corn fields," says Hoffmann. "We wanted them to become a permanent member of a complex of natural enemies that suppress the corn borer. Maybe further south they will overwinter and become established."

Research into this problem has been conducted since 1992. Prior to 1998, funding came from the New York State Integrated Pest Management program. Since 1998 the Pest Management Alternative program of the U.S. Department of Agriculture (Cooperative State Research, Education and Extension Service) has provided a three-year, $155,000 grant.


Story Source:

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


Cite This Page:

Cornell University. "Corn Borer Damage Can Be Halved By Releasing Army Of Wasps Early And Just Once, Says Cornell Research Report." ScienceDaily. ScienceDaily, 20 November 2000. <www.sciencedaily.com/releases/2000/11/001120075050.htm>.
Cornell University. (2000, November 20). Corn Borer Damage Can Be Halved By Releasing Army Of Wasps Early And Just Once, Says Cornell Research Report. ScienceDaily. Retrieved September 30, 2014 from www.sciencedaily.com/releases/2000/11/001120075050.htm
Cornell University. "Corn Borer Damage Can Be Halved By Releasing Army Of Wasps Early And Just Once, Says Cornell Research Report." ScienceDaily. www.sciencedaily.com/releases/2000/11/001120075050.htm (accessed September 30, 2014).

Share This



More Plants & Animals News

Tuesday, September 30, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

California University Designs Sustainable Winery

California University Designs Sustainable Winery

Reuters - US Online Video (Sep. 27, 2014) Amid California's worst drought in decades, scientists at UC Davis design a sustainable winery that includes a water recycling system. Vanessa Johnston reports. Video provided by Reuters
Powered by NewsLook.com
Argentina Worries Over Decline of Soybean Prices

Argentina Worries Over Decline of Soybean Prices

AFP (Sep. 27, 2014) The drop in price of soy on the international market is a cause for concern in Argentina, as soybean exports are a major source of income for Latin America's third largest economy. Duration: 01:10 Video provided by AFP
Powered by NewsLook.com
Mama Bear, Cubs Hang out in California Backyard

Mama Bear, Cubs Hang out in California Backyard

Reuters - US Online Video (Sep. 27, 2014) A mama bear and her two cubs climb trees, wrestle and take naps in the backyard of a Monrovia, California home. Vanessa Johnston reports. Video provided by Reuters
Powered by NewsLook.com
'Crazy' Climate Forces Colombian Farmers to Adapt

'Crazy' Climate Forces Colombian Farmers to Adapt

AFP (Sep. 26, 2014) Once upon a time, farming was a blissfully low-tech business on Colombia's northern plains. Duration: 02:05 Video provided by AFP
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