The Department of Primary Industries and Regional Development (DPIRD) has been responding to a Queensland fruit fly (Qfly) outbreak within the Perth metropolitan area since March 2020.
significant number of male Qfly were detected in the Perth suburb of Dalkeith through DPIRD’s permanent Qfly trapping grid. DPIRD responded quickly with the installation of supplementary lure trapping, which detected more male Qfly in nearby Claremont and Nedlands.
DPIRD immediately instigated an radication program aligned with the Code of Practice for Management of Queensland Fruit Fly. This included establishing a Quarantine Area over all of Dalkeith and parts of Claremont and Nedlands, and undertaking surveillance and baiting activities within the Outbreak Zone (200m from Qfly detections).
DPIRD Chief Plant Biosecurity Officer Sonya Broughton said DPIRD was well placed to respond to the incursions, having achieved eradication of Qfly from WA on seven separate occasions since 1989.
“Qfly is the most important economic pest of Australia’s horticultural industries, attacking both fruit and some fruiting vegetables. Freedom from Qfly allows WA to meet national and international requirements for market access of host produce,” Dr Broughton said.
“If eradication is not successful, WA will lose access to those markets which recognise that WA is free from Qfly, including avocados to Japan and strawberries to Thailand.”
Dr Broughton said at the very minimum the export protocols which are currently all based on east-west distribution in Australia (no Qfly in the west, no Mediterranean fruit fly in the east) would need to be renegotiated. This would be a lengthy process that would impact on current market access and protocols currently under negotiation’.
“The price competitiveness of WA produce would also be weakened as produce imported from interstate would no longer require treatment for Qfly, and WA produce would still be subject to treatment for Medfly on produce shipped interstate.”
Dr Broughton said in the early stages of the program Qfly detections were increasing every day, which indicated a breeding population, but early baiting of street trees had an immediate effect by reducing detection numbers.
“However, the eradication program was presented with an early challenge to contact approximately 2700 properties in the Outbreak Zone without door knocking, due to the CVOID-19 Pandemic,” she said.
“Contact with residents is essential to arranging access to all properties within the Outbreak Zone to identify host plants and conduct larvae searches in Qfly host fruit*, and to commence the application of spots of bait (using Naturalure®) on Qfly host trees, and shade trees when no hosts are present.”
Standard Operating Procedures were developed based on national and health government advice to allow door knocking to commence, due to a poor response to contact cards being left in mailboxes.
DPIRD also introduced a community awareness campaign to encourage residents to make contact about property access, as well as compliance with the Quarantine Area restrictions on moving and disposing of Qfly host fruit*.
As of 13 May 2020, the Outbreak Zone is approximately 339 hectares and the Quarantine Area approximately 1,160 hectares.
Dr Broughton said there was a still a lot of work ahead, with Qfly continuing to be caught every day, although numbers are now lower compared to the beginning of the campaign.
“We are still facing the challenges of resident concerns about social distancing, and also reluctance to throw away Qfly host fruit*, particularly if residents are opting to rely on their garden produce to reduce supermarket visits,” Dr Broughton said.
“These concerns have been a priority since the start of the eradication program, and we have therefore put effort into creating an eradication program that can cater for everyone’s needs — the health and safety of both residents and DPIRD personnel, while at the same maximising the success of DPIRD’s activities in once again eradicating Qfly from WA.”
This has meant developing new strategies not used in previous eradication programs, including providing residents with the option to have all their Qfly host fruit* removed, regardless of ripeness, as an alternative to weekly property visits to conduct baiting activities.
Ordinarily, under the Quarantine Area regulations, residents are only required to regularly remove ripening fruit — unripe fruit can be left on trees and plants.
Properties opting for no visits will also be required to host a Bio trap for eight weeks, which attracts and kills both male and female Qfly.
Dr Broughton said it was encouraging that the majority of residents were supporting the eradication effort and cooperating with field personnel.
The program has also received great support from local government, industry and businesses.
“There are additional activities that are also playing an important role in preventing spread and further breeding, to ensure eradication.“This includes regular inspections of extra Qfly supplementary lure traps installed near the Canning Vale Markets (dating from previous Qfly responses), where imported and exported produce transition as part of the supply chain.
“Additionally, all DPIRD Qfly permanent lure traps in the Suspension Zone (15km radius from Qfly detection points in Dalkeith) are being inspected once per week, and mass trapping has been introduced for hotspot areas in the Outbreak Zone to suppress fly numbers.
Mass trapping is a supplementary measure involving the placement of 50 Bio lure traps per hectare.
Dr Broughton said another challenge to the program has been green waste verge collections, with branches laden with fruit being left out for collection, and some being inadvertently transported out of the Quarantine Area.
“To address this, we have delivered information to all residents advising that green waste must be stripped of fruit, and additional Qfly lure traps have been installed at sites that are the end points for green waste collected in the Outbreak Zone. This means that any spread of Qfly to these sites should be detected.”
Dr Broughton said it was important to note there have been no Qfly detections in any commercial fruit or vegetable production areas within WA, and therefore to date no impact on interstate market access.
Area Freedom for Qfly has been suspended within the 15km Suspension Area, meaning commercial Qfly host fruit* grown within this area cannot be exported from the area without treatment or other approved protocol.
However, WA’s Area Freedom from Qfly remains in place for the remainder of WA.
MORE INFORMATION ► Visit agric.wa.gov.au/qflyupdate for more information on the eradication program, a map of the Quarantine Area and Outbreak Zone, and the Quarantine Area Notice.
*Fruit meaning any host of Qfly, including some fruiting vegetables, as listed in the Quarantine Area Notice