Ant supercolony spans 100 kilometres across Melbourne

11 August 2004

A giant supercolony of Argentine Ants stretching across the Greater City of Melbourne has been discovered by Ms Elissa Suhr from the School of Biological Sciences at Monash University.

Ms Suhr said the alien ants, which are listed as one of the world's 100 worst invaders may pose a serious threat to Melbourne's biodiversity.

Despite looking like a harmless household pest, the Argentine ant has the potential to displace native plants and animals.

Ms Suhr said change in genetic structure may have allowed the ants to multiply.

"In Argentina, their native homeland, ant colonies span tens of metres, are genetically diverse and highly aggressive towards one another. So, population numbers never explode and they are no threat to other plants and animals," said Ms Suhr.

"In Melbourne their genetic make-up and behaviour is really different. Here, Argentine ants no longer fight and have formed a supercolony extending at least 100 kilometres across the city".

The Argentine ant was first discovered in Victoria in 1939 and since then they have colonized every state.

But Australia isn't the only country to be affected by the outbreak.

By hitchhiking in international trade, the ants have spread to all Mediterranean ecosystems around the world and had huge impacts in other countries. For example, in California they have displaced native ants, decreased the diversity of other native insects, affected the dispersal of seeds and even decreased lizard numbers.

Ms Suhr hopes her findings will lead to a better understanding of the ants and ways to control their spread.

For further information or to arrange an interview contact Ingrid Sanders in Media Communications on +61 3 9905 9201. Elissa Suhr is available for interviews today (Wednesday) afternoon and Monday afternoons. Photographs are also available.