Featured Research

from universities, journals, and other organizations

'Fearless' aphids ignore warnings, get eaten by ladybugs

Date:
August 9, 2010
Source:
Cornell University
Summary:
'Fearless' aphids -- which become accustomed to ignoring genetically engineered chemical alarms in plants and alarms sent by fellow aphids -- become easy prey for ladybugs. That's good news for farmers, according to researchers.

An aphid that is attacked by a ladybug releases an alarm pheromone that causes nearby aphids to flee from danger.
Credit: Georg Jander

If your building has 10 false fire alarms one morning, it is human nature to ignore it when it goes off for the 11th time.

Related Articles


Similarly, when aphids are raised on plants genetically engineered to emit a compound that warns surrounding aphids of a predator, they become accustomed to the chemical and no longer respond to it -- even when a predator is present, according to Cornell and Boyce Thompson Institute (BTI) researchers reporting Aug. 3 in an online edition of the Proceedings of the National Academy of Sciences.

Under normal circumstances, when a ladybug captures and bites into an aphid, the victim releases an alarm pheromone called beta-farnesene, which prompts nearby aphids to walk away or drop off the plant. Researchers are interested in protecting plants from aphids through genetically engineered crops that produce beta-farnesene or through traditional breeding methods that cross crops with plants -- such as some wild and cultivated potatoes and peppermint -- that naturally produce the pheromone.

The findings have implications for controlling aphids in crops, which could be engineered to make aphids unresponsive to warnings of ladybugs and other predators, making them easy prey.

But, as this study shows, "simply engineering plants to produce beta-farnesene will not make them resistant," said Georg Jander, an associate scientist at BTI on Cornell's Ithaca campus and a senior author of the paper with Robert Raguso, a Cornell professor of neurobiology and behavior. "When we put ladybugs into the mix, the aphids that are habituated to alarm pheromone get eaten more by ladybugs," Jander added.

In the study, aphids reared continuously on genetically engineered Arabidopsis thaliana plants that produced beta-farnesene became habituated to the pheromone within three generations and no longer responded to the compound, even though they still produced it. The habituated aphids did produce more progeny, perhaps because they expended less energy on running away and could focus on feeding more when compared with normal aphids, said Jander. Still, normal aphids had a higher survival rate in the presence of predators and would likely outcompete the habituated aphids in a natural setting.

The study also revealed that 15 percent of the genes in normal aphids displayed altered gene expression within 30 minutes of exposure to beta-farnesene, but "aphids that have been growing on alarm pheromone plants don't show this altered gene expression response," said Jander.

The results reveal a systemic response to the pheromone. "Being afraid is not just about running away, it changes the physiology of the aphid," said Jander. "But these gene expression changes don't happen with the habituated aphids, so somehow the signaling pathway is altered."

Co-authors included Martin de Vos, a former BTI postdoctoral researcher; Wing Yin Cheng '10, both members of Jander's lab; and Holly Summers, a graduate student in Raguso's lab.

The study was funded by the National Science Foundation and the U.S. Department of Agriculture.


Story Source:

The above story is based on materials provided by Cornell University. The original article was written by Krishna Ramanujan. Note: Materials may be edited for content and length.


Journal Reference:

  1. M. de Vos, W. Y. Cheng, H. E. Summers, R. A. Raguso, G. Jander. Alarm pheromone habituation in Myzus persicae has fitness consequences and causes extensive gene expression changes. Proceedings of the National Academy of Sciences, 2010; DOI: 10.1073/pnas.1001539107

Cite This Page:

Cornell University. "'Fearless' aphids ignore warnings, get eaten by ladybugs." ScienceDaily. ScienceDaily, 9 August 2010. <www.sciencedaily.com/releases/2010/08/100806125510.htm>.
Cornell University. (2010, August 9). 'Fearless' aphids ignore warnings, get eaten by ladybugs. ScienceDaily. Retrieved November 26, 2014 from www.sciencedaily.com/releases/2010/08/100806125510.htm
Cornell University. "'Fearless' aphids ignore warnings, get eaten by ladybugs." ScienceDaily. www.sciencedaily.com/releases/2010/08/100806125510.htm (accessed November 26, 2014).

Share This


More From ScienceDaily



More Plants & Animals News

Wednesday, November 26, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

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
Pet Dogs to Be Used in Anti-Ageing Trial

Pet Dogs to Be Used in Anti-Ageing Trial

Reuters - Innovations Video Online (Nov. 26, 2014) Researchers in the United States are preparing to discover whether a drug commonly used in human organ transplants can extend the lifespan and health quality of pet dogs. Video provided by Reuters
Powered by NewsLook.com
From Popcorn To Vending Snacks: FDA Ups Calorie Count Rules

From Popcorn To Vending Snacks: FDA Ups Calorie Count Rules

Newsy (Nov. 25, 2014) The US FDA is announcing new calorie rules on Tuesday that will require everywhere from theaters to vending machines to include calorie counts. Video provided by Newsy
Powered by NewsLook.com
Feast Your Eyes: Lamb Chop Sent Into Space from UK

Feast Your Eyes: Lamb Chop Sent Into Space from UK

Reuters - Light News Video Online (Nov. 25, 2014) Take a stab at this -- stunt video shows a lamb chop's journey from an east London restaurant over 30 kilometers into space. Rough Cut (no reporter narration). 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