QUEENSLAND FRUIT FLY GROWER UPDATE

Weather favourable for fruit fly

The weather outlook for September is likely to see fruit fly that survived winter emerge f rom refuges in greater numbers. Favourable weather conditions are expected to result in fruit fly active and on the move earlier than usual.

Queensland fruit fly (Qfly) populations were higher than normal in the autumn of 2021 which saw more adults than usual enter the winter of 2021 and f ind warm refuges across the landscape. September forecasts of higher temperatures and higher minimum temperatures, suggests that surviving Qfly will be able to leave their refuges in spring and infest fruit found on trees or the ground in September. It is important to pick up or harvest and destroy all unwanted fruit at this time of year.

Spring hot spots

Historical data from the Goulburn Murray Valley fruit fly trapping grid has been examined to identify locations with activity that saw three or more Qfly trapped per week in August and September over the past four years. Past activity is an important trigger for increased monitoring and control. The following locations recorded f ruit fly activity in August and September through the regional trapping grid in recent years and so extra vigilance is required in these areas:

• Euroa • Katamatite

• Kyabram • Merrigum

• Mooroopna • Numurkah

• Shepparton • Tatura

• Strathmerton • Tongala

• Yarrawonga

Fruit fly activity

Qfly mate at sunset, provided temperatures at dusk are above about 16˚C. The temperature at sunset has been 16˚C in some areas in August which means new mating may have occurred. Extra vigilance is recommended in the areas of Shepparton and Tatura as temperatures at dusk were higher in these locations.

Fruit fly traps

Traps are an ideal way of determining whether or not Qfly is present in your orchard or near the house. It is recommended that traps are deployed all year round. Traps should be moved out of deciduous orchards in winter to areas where it is warmer and there are evergreen plants, as this is where Qfly will take refuge over winter. Femalebiased traps should also be placed in evergreen plants (e.g. lemon tree) that are situated near the house, packing shed or other relatively warm positions.

Fruit fly baits

Baits are the best method for controlling fruit flies before their populations get too big to handle through baits alone. Once Qfly is detected in traps, bait applications should commence as per label instructions.