No further sign of red imported fire ants

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No more active red imported fire ants have been found in WA to date.
Camera IconNo more active red imported fire ants have been found in WA to date. Credit: United States Department of Agriculture

A four-month hunt for more invasive South American red imported fire ants in WA has come up empty-handed but surveillance will continue until the end of next year.

State Government officers went into overdrive when six imported fire ant nests were found and destroyed at two adjoining tenanted properties at Fremantle Port in November.

It was the first time the pests had been detected in WA and sparked major concern one of the world’s worst pests would gain a foothold in WA.

The invasive ant species’ bite can be lethal and the pest sets up super colonies preying on invertebrates and vertebrates through their venomous sting, and by swarming bigger prey.

If introduced to WA, the ants could make outdoor areas unusable and cause structural damage to irrigation and electrical equipment.

Authorities have been surveying the port and nearby surroundings for any further signs of the pest since November, through the “first round” of surveillance of the eradication program.

The red imported fire ant quarantine zone in Fremantle.
Camera IconThe red imported fire ant quarantine zone in Fremantle. Credit: DPIRD/DPIRD

The first round has now ended, but five more rounds of surveillance and baiting will continue until the end of 2021.

DPIRD plant biosecurity manager John Van Schagen said the next rounds would require continued support from the Fremantle public and businesses.

“There have been no further detections of this exotic pest outside of the initial detection site at two adjoining tenanted properties at Fremantle Ports,” he said.

“The Fremantle community has been incredibly supportive and co-operative with our surveillance, baiting and quarantine activities but we don’t want that to end. “We need to keep up surveillance for at least two years to be sure we have eradicated the RIFA incursion.

“We ask the community to remain alert for any signs of unusual ants and report them to the department as soon as possible.”

The first round included surveying the outdoor areas of nearly 600 residential properties and more than 200 non-residential premises within 2km of the Fremantle Port, baiting within a 500mm radius around the two premises the ants were found, and collecting 2000 ant samples.

A quarantine area with restrictions on moving items that could transport the ants — including potted plants, hay, soil, shipping containers, and manure — is still in place around a 2km radius from the detection point.

A sniffer dog from Queensland, with the ability to detect a single ant from 30m away and half a metre underground, also joined the hunt.

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