Qfly Bayswater Industry Update #8 January 2024
Incident update
DPIRD detected a single male Qfly in a trap located at Welshpool in late December 2023. Eight additional traps were placed around the positive trap and all properties within a 200m radius of the positive trap were investigated with no more flies detected.
This single detection does not constitute an outbreak and will not change the current Quarantine Area Notice, but it will delay the re-instatement of area freedom to around the 12 March 2024.
Under the national fruit fly management protocol, reinstatement of area freedom is dependent on the absence of Qfly in the Quarantine Area for one generation plus 28 days or 12 weeks after the last wild fruit fly or larvae is detected (whichever is longer).
Pilot systems approach for host fruit from a Qfly export assurance zone update
DPIRD has been collaborating with industry to pilot an auditable, on-farm certification assurance procedure to facilitate intrastate movement of host product during a Qfly outbreak. This pilot is now underway with over 40 Swan Valley grape producers currently participating.
Currently, growers in a Qfly Export Assurance Area have three options to move their host fruits: Cold treatment, Methyl Bromide treatment and for Hass Avocado growers – hard green condition. The ‘Systems Approach’ for Host Fruit from a Queensland Fruit Fly Export Assurance Zone in Western Australia (CA-EAZ) pilot provides businesses with an alternative option to post-harvest treatment to continue to trade within Western Australia.
The CA-EAZ systems approach consists of multiple mitigations used in combination to manage Qfly risk. These are: fruit fly trapping, fruit fly bait spraying, crop monitoring, field hygiene and postharvest inspection. These are then audited against the operational procedure. The CA-EAZ also requires participating businesses to allow third party weekly trap inspections and fortnightly crop inspections.
This is the first time the CA-EAZ has been implemented in Western Australia. DPIRD is providing third-party trap inspection and crop monitoring services in addition to audit services.
Trap inspections began in October 2023 and crop monitoring began in December 2023 as fruit achieved critical ripeness stages. Since starting, the DPIRD inspection teams have completed 939 trap inspections and the crop inspection team have completed 12,316 random spot inspections over 579 property visits and estimate they have inspected more than 250,000 bunches of grapes on vines.
As of 12 January 2024, no Qfly have been detected in any of the 400 samples that have been submitted for testing, since the beginning of the program.
DPIRD has also begun to investigate how the systems approach can be adapted for other commercial host plants.
Seasonal pest alert
DPIRD staff and growers have observed higher than usual numbers of Mediterranean fruit fly (Medfly), in the Swan Valley this season. The likely cause of this is unharvested and untreated fruit dropped on the ground, due to movement restrictions under the Qfly Quarantine Area Notice.
Medfly activity is dependent on temperature with fly activity and numbers are greatest during warmer months. One life cycle takes 28-34 days to complete in summer and 60-115 days in winter.
As the temperature rises in spring, increased numbers of adults emerge from the ground and flies become active. If control is not started at this time, Medfly populations will grow and cause problems later in the season.