Quick facts about the eradication program

• Fire ants were first discovered at Wacol and at Fisherman Islands in February 2001.  It is thought that they were here at least ten years prior to this.  Fortunately, the DPI&F is confident that they caught these nasty creatures before the ants had caused irrevocable damage or spread too far for eradication.
  
  
• The DPI&F has achieved significant success in the battle to eradicate these ants, with over 65,000 nests found in 2001 down to less than 200 nests in the 2006/2007 financial year.  Of those most recent nests, monogyne or single queen nests are in the majority. Once discovered and analysed, nests are totally destroyed.
  
  
• The community support of the NFAEP remains high with members of the general public continuing to ring in reports or send ant samples for identification.
  
  
• Operations have finished in some 50 000 hectares; that is, following multiple treatment and surveillance passes, there is no evidence of fire ants in those areas.
  
  
• Treatment and surveillance activities continue in some suburbs with all formerly and currently treated areas declared Restricted Areas where movement controls are in force.

Treatment

Fire ant treatment consists of distributing a granular corn based bait, multiple times across the treatment zone.  Efficient methods of distribution allow areas to be covered quickly and cost effectively.  The worker ants are attracted to the bait, carrying it into the nest and feeding it to the queen, larvae and other workers.

The treatment only affects insects and does not harm people, animals or the environment.  A person or animal would need to eat at least his or her own body weight of bait within 24 hours for any likelihood of sickness.  The chemicals used break down quickly in sunlight. The bait contains less than one per cent active chemical.

Only very small quantities of bait (1/2 teaspoon or 83 grams per square metre) are used. This works out at 200 grams for a 1000 square metre suburban block.

The baits used to treat Fire Ants consist of crushed corn saturated in soy bean oil.  Two types of chemicals are used with the corn base:

• Methoprene
• Pyriproxyfen

These chemicals are insect growth regulators (IGRs).  They do not kill the ants but sterilise the queen and stop the larvae from developing into mature ants.  The worker ants are not replaced and the colony dies out.

The baits destroy about 80 percent of nests each time so several applications are needed - two to four times each year during the warmer months of September to May. The ants do not forage much in the cooler months (when the soil temperature reaches less than 20°C) so it is not effective to distribute baits over winter.

The bait is broadcast across designated treatment areas by field staff using hand operated spreaders, on All Terrain Vehicles or aerially from helicopters. Broadcast bait treatment is particularly effective because: it allows the chemical to be taken into nest to feed to the queen with minimal disturbance of the nest; picks up nests we cannot see; and is quick to cover areas.

Surveillance

Following at least two years of treatment, properties continue to be checked to ensure fire ants have been eradicated. A program of targeted surveillance surrounding treatment areas has also been conducted.  Surveillance is carried out by field officers who visually check every square metre of ground, forming emu parades over large properties. Officers carry long sticks and may tap pot plants or prod piles of earth to aid their visual search. FACC staff do not enter dwellings to conduct surveillance, needing access only to outside areas.

This formal surveillance is an integral part of the program but also essential to success is the surveillance carried out by members of the public checking their residences, business places and public spaces. A specialised team follows up on any suspicious ant activity which is reported by members of the general public.  Local government authorities assist by regularly checking parks and community areas. All reports of suspect ants are taken seriously and followed up by FACC.

Containment

To prevent fire ants being spread to new areas through the transport of materials containing nests or fertile queens, the DPI&F has implemented movement controls for high risk materials such as soil, pot plants and mulch. Residents and businesses operating inside the declared Restricted Areas must adhere to the movement regulations. Businesses that deal with these high risk materials within these zones must also have Approved Risk Management Plans.