The discovery of one of the world's most invasive ant species on the doorstep to the Daintree Rainforest could spell disaster for the World Heritage-listed site and its endemic plants and animals.
Electric ants, native to Central and South America, were first discovered in Cairns in 2006.
James Cook University invasive ant researcher Lori Lach said they ranked third-worst in the world in terms of environmental impact and first in terms of socio-economic impact.
"[That ranking] is splitting hairs between red imported fire ants, yellow crazy ants and electric ants — they're all really damaging to the environment," she said.
"What puts electric ants ahead on the socio-economic impact is what we see across the Pacific, where people have had to abandon their houses."
Dr Lach said what electric ants lacked in size — they only grow to about 1.5 millimetres in length — they made up for with their painful sting.
'We don't want this to spread'
The Daintree Rainforest is home to several vulnerable animal species, including the southern cassowary, Bennet's and Lumholtz tree kangaroos and the spotted-tailed quoll.
Prior to March 2022 electric ants had not been found north of the Daintree River, the demarcation line between the rainforest and sprawling populations to its south.
The species was detected at the Cow Bay Waste Transfer Facility, hundreds of metres from the World Heritage area boundary.
The discovery has prompted the Douglas Shire Council to temporarily restrict what residents can dump at the site.
The dump is no longer accepting large household items stored at ground level, like barbecues and white goods, but is still taking green and household waste.
"We don't want to spread this, so we are trying to minimise it," Douglas Shire Mayor Michael Kerr said.
"The biggest concern for us is that if things are sitting on the ground, that's where the ants can get into it — they can start nesting and then, when we remove those items from the transfer station to take them somewhere else, we're going to spreading them to other areas."
Untouched forest unaffected
Biosecurity Queensland's Gary Morton, the principal project officer for the National Electric Ant Eradication Program (NEAEP), said officers had discovered the suspected original infestation on a residential property north of the Daintree River.
They believe ants from that site spread to the dump at Cow Bay.
"The good thing for us with electric ants is that they don't fly and they don't move very far on their own," Mr Morton said.
"Experiments that we've done, and also in worldwide literature, show that they move anywhere from zero to 25 metres in a year on their own, so they're not big spreaders.
The NEAEP will soon ask Daintree residents to book their properties in for free checks to determine whether the ants have spread beyond the dump.
"For the untouched rainforest, we're confident that they're not in there, because they would need to be moved in there by us," Mr Morton said.
"For what is essentially the edge of the rainforest, it's about talking to the public and getting them involved."
A defenceless ecosystem
Dr Lach said the ants could cause havoc if they had a chance to establish themselves in the rainforest.
"Evidence we see from other areas around the world is that when electric ants get into forests they really change the composition of the arthropods and other insects in the forest," she said.
"The ecosystem isn't used to ants like that so it hasn't evolved any kinds of defences against it.
"That actually starts to affect the functioning of the rainforest, so we see decreased nutrient cycling and that can, over time, cascade to the point we see changes in other parts of the forest — trees, birds, butterflies and so on."
Mr Morton said the NEAEP had experience eradicating electric ants from similarly dense rainforest areas in Far North Queensland.
