Study shows pesticides make some ants more aggressive

Oct 23, 2013

(Phys.org) —Research carried out at Victoria University of Wellington shows that exposure to some commonly used pesticides makes an invasive ant species more aggressive and more likely to survive conflict with a native ant species.

At the same time, the native species becomes less aggressive after being exposed to the pesticide.

Led by PhD student Rafael Barbieri, Professor Phil Lester and Associate Professor Ken Ryan from Victoria University's School of Biological Science, the research is the first in the world to demonstrate the impact that neonicotinoid can have on dynamics in insect communities and invasion success.

Neonicotinoids are the world's most widely deployed insecticides and have been associated with the decline of honey bees and other pollinators. The chemical is often soaked into seeds and spreads throughout the plant as it grows, affecting insects that eat it. The European Commission recently imposed restrictions on the use of neonicotinoid pesticides for two years.

The study examined the invasive Argentine ant, which is widely established in New Zealand, and the native Southern ant. The two species have similar habitat and food preferences.

"The Argentine ant is already known as an extremely aggressive invader, all around the world," says Professor Lester. "Here you have the Ghengis Khan of the ant world becoming even more aggressive after exposure to these pesticides.

"The success of such is often linked to their highly aggressive behaviour and to their ability to displace native communities and manipulate food sources."

Mr Barbieri says the level of increased aggression displayed by the Argentine ants as they faced off over food supply with their native competitors was significant.

"The native ant was clearly less able to hold its own when it was contaminated by sub-lethal amounts of the pesticide."

"In habitats where the local species has previously been exposed to neonicotinodis, invading Argentine ants are likely to have significantly higher chances of monopolising and higher survival rates."

Overall, say the researchers, their results provide evidence that sub-lethal exposure to these pesticides can have a major effect on the dynamics of ant communities.

The Victoria University research was today published in the international journal Proceedings of the Royal Society B.

Explore further: 100,000 bird samples online

More information: A neurotoxic pesticide changes the outcome of aggressive interactions between native and invasive ants, rspb.royalsocietypublishing.or… .1098/rspb.2013.2157

Related Stories

Invasive tawny crazy ant found in Georgia

Sep 18, 2013

The tawny crazy ant has made its way into Georgia for the first time. University of Georgia Extension agent James Morgan in Dougherty County discovered the ant—which originates in South America—on Aug. ...

Angry wasps deal to their competitors

Mar 30, 2011

(PhysOrg.com) -- Scientists at Victoria University have identified a surprising and previously unknown behaviour in the animal world by studying interactions between native ants and invasive wasps in South Island beech forests.

Recommended for you

A molecular compass for bird navigation

6 hours ago

Each year, the Arctic Tern travels over 40,000 miles, migrating nearly from pole to pole and back again. Other birds make similar (though shorter) journeys in search of warmer climes. How do these birds manage ...

100,000 bird samples online

7 hours ago

The Natural History Museum (NHM) in Oslo has a bird collection of international size. It is now available online.

New genetic technologies offer hope for white rhino

9 hours ago

With support from the Seaver Institute, geneticists at San Diego Zoo Institute for Conservation Research are taking the initial steps in an effort to use cryopreserved cells to bring back the northern white rhino from the ...

Cats put sight over smell in finding food

Feb 26, 2015

Cats may prefer to use their eyes rather than follow their nose when it comes to finding the location of food, according to new research by leading animal behaviourists.

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.