Keeping WA free from browsing ant
Surveillance activity for the exotic browsing ant is underway at targeted premises across Western Australia in areas considered at risk.
Browsing ant, Lepisiota frauenfeldi, is an exotic ant species not yet established in Australia that would likely become a significant horticultural, environmental and domestic pest if it were to establish.
With Western Australia’s horticultural industries production valued at more than $1.1 billion per year and employing more than 5600 workers, it is important that exotic species like browsing ant that could threaten our horticultural sector are quickly eradicated to prevent establishment.
Since July, the Department of Primary Industries and Regional Development’s (DPIRD) surveillance team, made up of Lilli-Mai Rebel, Rob Coupar, Lachlan Petersen and Vaniek Paille, has surveyed 125 properties across the state looking for any evidence of browsing ant.
Sites are considered ‘at risk’ and chosen for surveillance if they have been associated with or are in close proximity to known infested sites, or if they regularly receive overseas freight or cargo such as shipping and airfreight containers, pallets, plant nursery stock or green waste.
Browsing ant has not been discovered at any of the at risk properties surveyed to date.
What is browsing ant?
Browsing ants are a slender, shiny, dark brown ant about 3–4mm in length. They have long antennae and long legs, and run about in a crazy or haphazard manner when disturbed. They do not have a strong 'ant smell' when crushed.
They can gather in large numbers in trees and bushes, eventually killing the plants they live on.
Browsing ant in Australia
Browsing ant was first found in Australia at Perth Airport in 2013. The size and spread of this infestation indicated it had been in place at least five years.
With high volumes of freight and cargo moving from the airport, it was considered highly likely browsing ant could have been accidentally transported to other areas in WA and indeed browsing ants have since been found at three other sites linked to Perth Airport.
Browsing ant has been eradicated from these sites, but surveillance continues to determine if there has been further spread.
There were browsing ant discoveries in Darwin in 2015 and Brisbane in 2019 where they are under eradication.
WA’s browsing ant response
DPIRD’s browsing ant response team is undertaking a two-year, state-wide surveillance and response program. Eradication can only be declared if there has been no evidence of surviving colonies after two years of surveillance.
Program milestones include the surveillance of at least 500 different sites over the two years, treatment of any browsing ants discovered, and two ‘Ant Blitzes’, which will form the passive surveillance component of the program and involve the community submitting reports or specimens.
Treating and eradicating browsing ants
To treat browsing ant, granular baits containing an insect growth regulator designed to sterilise the queens, customised to attract browsing ants, are broadcast across the infested area, followed by a spray treatment two weeks later.
Specially trained browsing ant detector dogs are used during post-treatment surveillance to help determine if the ant has been successfully eradicated.
The dogs can cover substantially more ground in a shorter time than humans searching for ants, and can sniff out a single browsing ant from several metres away.
Report browsing ant
If you suspect you have browsing ants at your property or workplace please report it via the MyPestGuide reporter app (mypestguide.agric.wa.gov.au) or contact the Pest and Disease Information Service on (08) 9368 3080 or padis@dpird.wa.gov.au.