Outbreaks and Detections

We respond to fruit fly detections and outbreaks to protect South Australia. Below is our process.

Detections

Fruit flies can be detected in trapping sites around Australia, and by members of the public reporting larvae in fruit to us through the 24 hour Fruit Fly hotline: 1300 666 010.

There are trapping sites in:

  • metropolitan Adelaide
  • the northern Adelaide Plains
  • the Adelaide Hills
  • the Riverland
  • Port Augusta
  • Ceduna
  • Pt Lincoln

We use additional traps in the area if fruit flies are detected. We also check fruit trees for fruit fly larvae if detections are made.

Below are the conditions required for an outbreak to be declared.

Outbreaks

A Queensland fruit fly (Q-fly) outbreak is declared when any of the following occurs:

  • 5 male or non-pregnant female flies are trapped within 1 km within a rolling 2 week period
  • 1 pregnant female is detected
  • 1 or more larva are detected in locally grown fruit.

A Mediterranean fruit fly (Med-fly) outbreak is declared when any of the following occurs:

  • 3 male or non-pregnant female flies are trapped within 1 km within a rolling 2 week period
  • 1 pregnant female is detected
  • 1 or more larvae are detected in locally grown fruit.

In the event of an outbreak we:

  • define a quarantine area of 1.5 km radius from which host fruit cannot be removed
  • ensure no host fruit or vegetables, other than preserved or cooked is removed from properties in the area
  • establish a suspension zone of up to 15 km within which host fruit is treated prior to removal
  • destroy all fruit on infested trees in the  eradication area
  • undertake bait spotting
  • release sterile fruit flies
  • continue to apply bait spotting for at least 2 weeks.

Bait spotting

We use bait spotting to destroy fruit flies in an outbreak.

Spots of organic fruit fly bait are applied onto plants once or twice a week for several weeks. The baits attract and kill the fruit flies.

The bait is made with Naturalure™ fruit fly bait concentrate diluted with water. Naturalure™ has been certified as organic by Biological Farmers of Australia.

Hygiene

We visit properties within 1.5km of the outbreak centre and remove, treat and dispose of fallen host fruit and vegetables

Sterile insect technology

Sterile insect technology (SIT) is a method where sterile male flies are released to mate with any remaining wild female fruit flies.

We release sterile fruit flies during some responses into the quarantine area after completing bait spotting. The decision to release sterile flies is made in consultation with entomologists and based on factors such as the time of year at which detections are made and the number of flies discovered.

1,000,000 sterile flies are released per square kilometre once or twice a week for up to 12 weeks. The sterile flies mate with females who then lay infertile eggs. That prevents the fruit flies from replicating and spreading.

The sterile flies are produced at the Sterile Insect Facility in Port Augusta.

Contacts

Biosecurity SA Fruit Fly Program
Email: PIRSA.planthealth@sa.gov.au
Phone 24 hours: (08) 8207 7820

Fruit Fly Hotline: 1300 666 010

Page Last Reviewed: 06 Oct 2017
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