22 - 24 September 2009

Quantitative data was obtained over two seasons (2007-2009) to assess whether a dynamic and strategic trapping approach provides an equal or higher level of statistical confidence as the current static and passive grid to prove area freedom from the Queensland fruit fly (QFF), Bactrocera tryoni (Froggatt) and Mediterranean fruit fly (MFF), Ceratitis capitata (Wiedemann). The benefits of a more efficient monitoring system are reduced costs for trap deployment and eradication and lower environmental impacts. Data was collected (fly numbers and host phenology) weekly through the year but fortnightly in winter in Western Australia (WA), New South Wales (NSW), South Australia (SA) and Victoria. Besides field research in WA and NSW, data was mined from historical outbreaks in area free zones of NSW, SA and Victoria.

In Western Australia, MFF traps were deployed (in towns and on farms) in four geographical locations at 48 sites (2007-08) and 59 sites (2008-09). A 200 metre zone around each site was mapped and fruit phenology recorded at each trap check. The sites were chosen based on previously known population densities Donnybrook (>2/flies/trap/week); Manjimup (<2/flies/trap/week); Pemberton (0/flies/trap/week); and in Kununurra area free zone (0/flies/trap/week). A higher percentage of MFF were invariably captured in dynamic versus static traps.

In NSW (2007-08), QFF traps were deployed and host phenology recorded in three towns Cootamundra (30 sites), Junee (30 sites) and Gundagai (30 sites). In the 2008-09 season, the town Ganmain (24 sites) located near a zero QFF area replaced Gundagai. In the 2007-08 season, there were higher QFF numbers in January to early March. In Cootamundra dynamic traps had more fruit flies than static traps. At other sites there was no difference. From late March - June fly numbers differed between sites with Cootamundra < Junee < Gundagai. In May static traps caught more flies than dynamic traps in Junee. Cootamundra had higher catches in dynamic traps compared with static traps for pome fruit. There were no differences in Gundagai. In 2008-09, QFF numbers were particularly high from mid-February until mid-April in Cootamundra and from mid-January until mid-March in Junee. In Ganmain, densities were low and flies were only trapped for eight weeks. In all towns except Junee, more QFF were trapped in dynamic as opposed to static traps.

QFF data was mined in the risk reduction zone (RRZ) in the Riverina from 2003-2008 from the NSW Department of Industry and Investment (DII) Pestmon database giving a total of 486 record sets in citrus, pomefruit, stone fruit, and other trees. To stratify regional effects the trapping areas included fourteen towns in inland NSW.

In SA, data mining of QFF outbreaks was done to record surrounding properties for infested fruit within a radius of 200m of each outbreak site. These data were combined with data extracted from overhead imagery for 10 QFF detection sites to compare areas where detections resulted in outbreaks with areas where detections did not result in an outbreak.

In Victoria, QFF trapping data extracted from the Victorian fruit fly database ‘Flybase’ was combined with the results of seasonal fruit tree phenology and geographical information (water courses/bodies) for more detailed analysis.