Featured Research

from universities, journals, and other organizations

Aphids Make 'Chemical Weapons' To Fight Off Killer Ladybirds

Date:
July 12, 2007
Source:
Imperial College London
Summary:
Cabbage aphids have developed an internal chemical defence system which enables them to disable attacking predators by setting off a mustard oil "bomb," says new research.

When an aphid is attacked by a predator chemicals in its blood are mixed with an enzyme in its muscles to produce deadly mustard oil which repels the predator.
Credit: Image courtesy of Imperial College London

Cabbage aphids have developed an internal chemical defence system which enables them to disable attacking predators by setting off a mustard oil 'bomb', says new research.

Related Articles


The study shows for the first time how aphids use a chemical found in the plants they eat to emit a deadly burst of mustard oil when they're attacked by a predator, for example a ladybird. This mustard oil kills, injures or repels the ladybird, which then saves the colony of aphids from attack, although the individual aphid involved usually dies in the process.

When the aphids feed on cabbages, they consume chemicals called glucosinolates which are found in the nutrient transport vessels of the plant. Once eaten, these chemicals are then stored in the aphids' blood. Mimicking the plants themselves, the aphids also produce an enzyme called myrosinase, which is stored in the muscles of their head and thorax. In the event of a predator attack this enzyme in the muscles comes into contact with the glucosinolates in the blood, catalysing a violent chemical reaction which releases mustard oil.

The research team from the UK and Norway confirmed their findings by controlling the diet of different groups of aphids. They found that those insects eating a diet rich in glucosinolates had a high success rate in fending off predators, whereas those without glucosinolates in their diet did not. Scientists already knew that aphids absorbed these chemicals from their food, but this study published Proceedings of the Royal Society B is the first of its kind to prove that they form the basis of a chemical defence system.

The scientists also found that the extent to which glucosinolates are stored up by the aphids from birth into adulthood depends on whether or not they develop wings. Those aphids that grow wings see a rapid decline in the amount of glucosinolates they store from the time wing buds start to develop.

Dr Glen Powell from Imperial College London's Division of Biology, one of the paper's authors, explains: "Our study seems to show that aphids that develop wings cease to store this chemical in their blood as they mature, as they don't need the 'mustard oil bomb' to defend themselves from predators when they can just fly away. This is a great example of the way in which a species provides an ingenious method of protecting itself, whatever the circumstances."

Dr Powell adds: "In the wild, aphids live in clonal colonies, with often many hundreds of individuals crowded together on a plant, and using this poisonous mustard oil defence provides wingless individuals with a powerful means of dispelling a predator which poses a risk to the entire colony. Unfortunately the nature of the mechanism -- with the chemical stored in the insect's blood and the catalyst stored in its muscles -- means that in most cases the individual aphid responsible for seeing-off the ladybird predator dies in the process of protecting the colony."

Authors and reference: 'The cabbage aphid: a walking mustard oil bomb,' Proceedings of the Royal Society B: Biological Sciences, Wednesday 11 July 2007.

Eleanna Kazana (1), Tom W. Pope (1), Laurienne Tibbles (1), Matthew Bridges (1), John A. Pickett (2), Atle M. Bones (3), Glen Powell (1) and John T Rossiter (1).

(1) Division of Biology, Faculty of Natural Sciences, Imperial College London, Wye Campus, Ashford, Kent TN25 5AH.

(2) Biological Chemistry Division, Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ.

(3) Department of Biology, Norwegian University of Science and Technology, 7491 Trondheim, Norway.


Story Source:

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


Cite This Page:

Imperial College London. "Aphids Make 'Chemical Weapons' To Fight Off Killer Ladybirds." ScienceDaily. ScienceDaily, 12 July 2007. <www.sciencedaily.com/releases/2007/07/070711105844.htm>.
Imperial College London. (2007, July 12). Aphids Make 'Chemical Weapons' To Fight Off Killer Ladybirds. ScienceDaily. Retrieved October 24, 2014 from www.sciencedaily.com/releases/2007/07/070711105844.htm
Imperial College London. "Aphids Make 'Chemical Weapons' To Fight Off Killer Ladybirds." ScienceDaily. www.sciencedaily.com/releases/2007/07/070711105844.htm (accessed October 24, 2014).

Share This



More Plants & Animals News

Friday, October 24, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Deep Sea 'mushroom' Could Be Early Branch on Tree of Life

Deep Sea 'mushroom' Could Be Early Branch on Tree of Life

Reuters - Innovations Video Online (Oct. 24, 2014) Miniature deep sea animals discovered off the Australian coast almost three decades ago are puzzling scientists, who say the organisms have proved impossible to categorise. Academics at the Natural History of Denmark have appealed to the world scientific community for help, saying that further information on Dendrogramma enigmatica and Dendrogramma discoides could answer key evolutionary questions. Jim Drury has more. Video provided by Reuters
Powered by NewsLook.com
Black Bear Cub Goes Sunday Shopping

Black Bear Cub Goes Sunday Shopping

Reuters - Light News Video Online (Oct. 23, 2014) Price check on honey? Bear cub startles Oregon drugstore shoppers. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Dances With Wolves in China's Wild West

Dances With Wolves in China's Wild West

AFP (Oct. 23, 2014) One man is on a mission to boost the population of wolves in China's violence-wracked far west. The animal - symbol of the Uighur minority there - is under threat with a massive human resettlement program in the region. Duration: 00:41 Video provided by AFP
Powered by NewsLook.com
Breakfast Debate: To Eat Or Not To Eat?

Breakfast Debate: To Eat Or Not To Eat?

Newsy (Oct. 23, 2014) Conflicting studies published in the same week re-ignited the debate over whether we should be eating breakfast. Video provided by Newsy
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