36 million sterile flies released across Perth’s western suburbs as part of war against Queensland fruit fly

Millions of sterile flies are being released across Perth’s most exclusive suburbs as the State Government closes in on an outbreak of one of the world’s worst pests. The Queensland fruit fly, which was first detected in Perth in March, could destroy the livelihoods of local fruit growers and cost WA nearly $40 million a year if it becomes established here. It could also end WA’s access to international markets for some types of fruit such as avocados to Japan and strawberries to Thailand. About 36 million sterile flies will be released across affected areas from today to disrupt the breeding cycle of the remaining pests. The sterile male flies will mate with the female fruit flies, leading to infertile eggs and no future hatching of larvae. The release follows a major program by the Department of Primary Industries and Regional Development since March, covering more than 2000ha and 13,600 premises across western suburbs including Nedlands, Dalkeith, Claremont, Peppermint Grove and Shenton Park. Fruit was stripped from trees and a major surveillance program began. On average, 236 department staff have worked on the program each day, costing about $10 million. Agriculture Minister Alannah MacTiernan said more than 120,000 property inspections had been completed, 250,000 host plants identified and close to 20,000 baiting and trapping devices deployed. The effort was paying off, she said. No fruit flies had been detected since August, and no larvae since September. “Releasing sterile flies, while the Qfly population is very low, allows us to mop up any remaining wild Qfly in the outbreak area,” Ms MacTiernan said. “Keeping this pest out allows WA growers to continue to access important export markets, and we can have beautiful fruit at home.” The same technique was used successfully to eradicate Queensland fruit fly from an area covering about 800sqm in Perth in 1990. The sterile flies are dyed with a fluorescent powder which glows under UV light for easy identification.