Favourable conditions for fruit fly

The 2020/21 fruit season has been a particularly bad year for Queensland fruit fly. Despite the positive efforts of communities in keeping fruit fly numbers down within the Goulburn Murray Valley, the impacts of favourable weather conditions have resulted in the survival and spread of fruit fly. There is no doubt the situation would have been worse without the work of these communities and continued vigilance is more important than ever.

Favourable weather conditions are due to the La Niña weather pattern present in South Eastern Australia since March 2020. La Niña is still present but weakening and is expected to be neutral by mid-autumn.

Autumn control essential

More fruit fly on the landscape means any fruit that is around will be infested. Seemingly insignificant fruit such as the odd roadside feral peach, or a bank of prickly pears, will be heavily attacked and become the source of large new populations.

It is essential to clean up and destroy as many fruit fly host fruit as possible. Community members are asked to be on the lookout for feral fruiting plants, untended fruit in abandoned orchards, vacant ground, creek banks, roadsides and rental properties, as well as front, side and back yards. Even small numbers of fruiting plants will be targeted by Queensland fruit fly under La Niña weather conditions and must be controlled.

Fruit fly activity

Cobram urban and Cobram rural are showing low numbers now, when in previous years they registered higher numbers. It is likely that the sterile insect technique pilot trial, now in its second year in Cobram, has had a significant beneficial impact.

Other locations are proving much more difficult to reduce fruit fly. These are referred to as ‘hot spots’ and have been identified and are being targeted as a result of the Goulburn Murray Valley Area-Wide Management strategy. The main Queensland fruit fly hot spots on the regional trapping grid include:

  • Merrigum
  • Nagambie
  • Katamatite
  • Katunga
  • Numurkah
  • Euroa
  • Ardmona