Exotic Ants Threaten Aboriginal Communities

"Exotic ants are some of the world's worst invaders," says CSIRO ecologist, Dr Ben Hoffmann.

The three worst species affecting the Tiwi Islands include the African big-headed ant (Pheidole megacephala), the Ginger ant (Solenopsis geminata), and the Singapore ant (Monomorium destructor).

"It's amazing how quickly these species have taken over Tiwi communities, almost the entire community of Pirlangimpi on Melville Island is one huge supercolony of African big headed ants," says Dr Hoffmann.

Dr Hoffmann said the community of Nguiu on Bathurst Island has spent more than $70,000 in the past 12 months fixing electrical problems due to the Singapore ant.

"I have never seen an infestation of Singapore ants like this before, the magnitude of damage is really overwhelming", he says.

Ginger ants are notorious for their painful sting, which can cause allergic reactions in people. Dr Hoffmann says Milikapiti was the worst affected community with more than 260 colonies found so far.

"Many houses were totally surrounded by ginger ants, preventing people from using their yards", he says.

Another serious pest, the Yellow Crazy ant (Anoplolepis gracilipes), has invaded north-east Arnhem Land in the Northern Territory and has the capacity to spread right across the north to Broome.

Dr Hoffmann says pest ants, particularly the African Big-headed ant and the Yellow Crazy ant, can form huge colonies, totally displacing native animals and seriously disrupting ecological processes.

"They are a major threat to the environment and are also a serious pest of agriculture as they cause outbreaks of sap-sucking insects, which harm plants."

Tiwi Land Council Board member, Cyril Kalippa says it was most likely that the pest ants came to the Tiwi Islands from Darwin in goods such as pot plants and building materials.

"These pest ants have been spread throughout the world by people and they are now getting a strong hold in our communities. We want to keep the country as it is. The way it was before these ants came. So we would like to eradicate them as soon as possible", he says.

A Northern Land Council spokesperson says the threat of exotic pest ants should not be underestimated.

"Pest ants have the capacity to spread to all Aboriginal communities throughout the Top End. We have an opportunity now to do something about them while their distribution is limited. It will cost money but if we act quickly it will be far more cost efficient than if we wait 10 years".

The Northern Land Council, the Tiwi Land Council and CSIRO are currently developing a proposal for controlling pest ants on Aboriginal Land across northern Australia.