May is the time for post harvest hygiene

During the first two weeks of April 2019, a total of 389 flies were trapped in the 375 traps deployed in the Goulburn Murray Valley (GMV) giving an average of 1.03 flies per trap per week (FTW). There were 253 flies (1.00 FTW) found in rural trap sites (252 sites) and 136 flies (1.08 FTW) in urban sites (125 sites). Normally, trap capture rates are higher in urban areas than in rural areas. However, as forecast last month, rural rates are catching up with urban rates as more and more fruit become attractive to Queensland Fruit Fly (QFF) in rural areas. Rural trapping rates are now on the increase as QFF move from urban areas, where fruit fly host material is now relatively limited into rural sites where a large volume of fruit fly host material is currently ripening. Urban FTW peak, usually, in late September and then again over an extended period from mid-December to late January. Rural FTW, on the other hand, tend to peak over the period from mid-March to early May.

Queensland Fruit Fly hot spots

If your commercial orchard is close to the following urban areas which are, at present, registering high QFF populations, you should be ready to commence QFF control programs (if you haven’t already done so).

• Ardmona
• Cobram
• Echuca
• Grahamvale
• Kyabram
• Merrigum

If QFF populations follow the same patterns as in 2017 and 2018, QFF start to become a problem in rural areas from mid to late-January. This did not occur in 2019, possibly due to a significantly hot and dry summer. However, with the advent of cooler days during early autumn the number of fruit flies are now increasing in rural areas and decreasing in urban areas. This is the normal pattern but delayed a few weeks due to the adverse impacts of the weather. Also, this means that the hot, dry summer and community-based area wide programs have, in fact, killed out a large proportion of the QFF population.

It is highly recommended to commence a bait-application program and ensure that your traps are fresh (following label instructions). Place them in suitable locations to intercept QFF coming into your orchard.

The GMV Fruit Fly Project can also assist with the free removal of unmanaged residential fruit trees and unmanaged orchards. Please contact the GMV Regional Fruit Fly Office by phoning (03) 5871 9222 or emailing gmvfruitfly@moira.vic.gov.au