Queensland Fruit Fly Outlook – January 2026

This information has been commissioned by the Goulburn Murray Valley Area Wide Management Fruit Fly Program and is funded by the Victorian Government. Use of this material in its complete and original format, acknowledging its source, is permitted, however unauthorised alterations to the text or content is not permitted.

Summary

Weather forecasts for the GMV suggest that Qff buildup may be reduced due to warmer maximum temperatures than usual in January 2026. Rainfall is likely to be no more than average so this, too, will further limit Qff survival. Rainfall and associated increases in humidity is forecast for late January. If this occurs, then surviving Qff will mate and infest existing ripening and ripe fruit. Removal of fruit (or the whole plant if it is not wanted) now is an important measure in reducing future fruit fly problems.

Trapping data collection, although in its early stages due to the commencement of a new trapping grid, shows that Qff is building up in some areas of the GMV especially in the towns of Numurkah, Yarrawonga and Strathmerton with slightly less pressure in Cobram, Koonoomoo, and in and around Shepparton.

Elevated Qff populations have also been found in peri-urban and rural locations meaning that extra vigilance must be exercised in these areas to prevent the translocation of Qff into nearby commercial crops.

Population reduction can be further achieved by increasing fruit fly management that commenced in spring. Continued active management is necessary to avoid population build up in late summer and autumn when most of the GMV’s crop ripen.

New trapping grid

A new Queensland fruit fly (Qff) trapping grid was installed throughout the Goulburn Murray Valley (GMV) around 19 December 2025 (Fig. 1). Trap inspectors deployed 249 new Lynfield traps charged with the Qff attractant, cue-lure, and the toxicant, malathion across 39 towns in 13 postcode areas. The area covered spreads from Cooma in the southwest to Koonoomoo in the northwest, across to Yarrawonga and through Tungamah and down to Shepparton, Toolamba and Mooroopna.

Traps were placed in rural (141 traps), peri-urban (56 traps) and urban (52 traps) locations.

Traps will be monitored for the presence of Qff adults periodically and monthly reports will be compiled showing trends in Qff population buildup and decline.

As of 5 January 2026, traps in the trapping grid were inspected from 1 to 4 times.

Results

Traps were inspected between 19 December 2025 and 5 January 2026 – i.e. a period of about 3 weeks.

A total of 434 adult Qff was trapped from a maximum of 249 traps. However, 172 of these traps (i.e. about 69% of available traps) did not trap any Qff (Fig. 2). This implies that, currently, Qff is not widely spread across the GMV. It is concentrated in a relatively few locations.

Fig. 1. New Queensland fruit fly trapping grid deployed during December 2025 in the Goulburn Murray Valley

Trends

It is too early to describe trends over time in Qff trapping rates given the short period the new trapping grid has been in place. However, it is likely that adult Qff that survived the winter have mated and laid eggs in feral and otherwise untended fruit in late spring, leaving a potentially large population of immature life stages of Qff – eggs, larvae and pupae. These will have matured to adult Qff flies by now and will have mated and laid more eggs during December and January in untended fruit – most likely in home gardens and backyards.

Towns

Some towns have already shown high numbers of trapped Qff while others are still minimal. Table 1 shows that Qff populations are relatively high in Numurkah, Strathmerton and Yarrawonga with 2 or more Qff per trap over the three week period from 19 December 2025 to 5 January 2026.

Table 1. GMV towns ranked in descending order of Qff prevalence (data from traps (n=249) monitored from 19 Dec 2025 to 5 January 2026).

Hot spots

Twenty traps captured more than 6 Qff over the same period. The locations of these 20 traps are considered to be Qff hotspots (Table 2).

NOTE – Definition of a Qff Hotspot: Under current Qff populations, this early in the Qff season for the GMV, a trap site where more than 2 Qff are trapped per week is considered a Qff hotspot

Table 2. Hotspot towns (In alphabetical order)

Table 2 shows that by mid-January 2026 some towns had larger Qff populations than others. This is reflected by the volume and type of Qff host plants in each location as well as the level of fruit fly management being employed there.

People living in all areas, especially those listed in Table 2, should be vigilant in checking traps and for fruit infestation especially in locations with more than 2 Qff trapped per week.

Tip: make sure your traps are charged with new lures and are not damaged. Otherwise replace. Also make sure that the traps are clear of foliage and branches and out of the sun in the hottest part of the day.

Tip: Make a habit of checking any nearby fruit for sting marks and/or infestation with maggots – even if the fruit is a roadside feral plant. If there are signs of infestation remove the fruit or the entire plant if you can.

Land use type

Urban trap sites are the main source for higher populations of Qff when compared to peri-urban and rural location (Fig. 3). As urban fruit ripens and drops, is harvested or is eaten by birds Qff will migrate from urban areas into peri-urban sites and then into commercial crops. This is currently occurring in the GMV as evidenced by the high Qff population pressure in peri-urban trap sites.

Peri-urban crops are now at higher risk of infestation. This means that nearby commercial horticulture is at an elevated risk of future infestation.

Table 3 shows that there are three towns some of whose peri-urbans trapping sites should elevated Qff presence. People managing gardens and orchards close to these areas should exercise Qff monitoring and control. These areas act as conduits to nearby commercial horticulture.

Table 3. Towns where peri-urban locations have significant Qff presence.

Unusually high levels of Qff have also emerged in some rural locations (Table 4). These should be of high concern to growers in these areas. Growers should have implemented regular Qff monitoring and control.

Table 4. Towns where rural locations have significant Qff presence.

Tip: Urban gardeners should feel a responsibility to reduce Qff populations in their yards not only to produce good quality fruit in their own gardens but also to reduce the influx of Qff into other areas – especially commercial orchards.

Forecast

In the GMV, fruit fly numbers generally increase in severity from late November and peak in December with a second peak in the autumn. Qff builds up very rapidly in urban and peri-urban sites with a mixture of high amounts of untended fruit, garden irrigation and evergreen refuges while rural sites remain quite low as there is still not much ripe fruit around. Rural sites with high Qff numbers at this time are likely to have persistent Qff populations surviving in untended home gardens and untended non-commercial fruit trees on the block.

Tip: Even if your commercial crop is well-managed with respect to Qff you must ensure that all other fruiting plants in and near your orchard are well-managed (or removed), too. Qff will move from the old apricot tree in the fowl yard into the next ripening crop nearby.

As urban crops decline with harvest and bird predation in the summer Qff populations also decrease while peri-urban and rural increase. This reflects the movement of Qff from urban, through peri-urban and into rural areas from mid-summer to autumn. This occurs due to the “pull” of large volumes of commercial crops ripening in rural areas at this time.

It is expected that similar trends will occur during 2025/26. The size of the peaks and their timing will depend on weather and fruit fly management measures implemented during the spring and early summer.

Weather

Bureau of Meteorology  http://www.bom.gov.au/climate/outlooks/#/overview/summary/ – accessed 8 January 2026:

The long-range forecast for January to March shows:

• Rainfall is likely to be below average for parts of Australia’s south and north-west; a weak or mixed signal for rainfall elsewhere, meaning roughly equal chances of a wetter or drier 3 months.
• Daytime temperatures are likely to be above average across Australia.
• Overnight temperatures are very likely be above average across most of Australia.

Forecast weather conditions for Shepparton for January 2026 (https://www.visualcrossing.com/weather/weather-data-services – accessed 8 January 2026) indicate likely high temperatures, low humidity and very little rainfall (Figs 4 & 5) at least up to about 21 January. This could be detrimental to the survival capability of adult Qff as well as immature life stages – especially if infested fruit fall to the ground and are subsequently exposed to the sun. At these temperatures eggs and larvae will die. Eggs and larvae in fruit in the shade and on the tree may survive.

Many adult Qff, however, being quite resilient will move to cooler, more humid locations in bushy evergreen foliage if they can – often during the cooler late afternoon. Low humidities, however, will reduce their ability to fly long distances.

This suggests that Qff populations may be impacted adversely during the early summer. Vigorous area-wide management programs will enhance Qff control significantly if set in place.

Surviving adult and immature Qff will welcome rainfall, lower temperatures and higher relative humidity in late January. This cohort of Qff will serve as the inoculum for the next wave of Qff-based problems leading into autumn when much of the GMV’s commercial horticulture ripens.

The Bureau of Meteorology forecasts (Figs 6, 7 & 8), for the GMV, higher than average maximum temperatures (60% to 65% chance of being higher than the average of 27°C to 33°C) and higher than average minimum temperatures (60% to 65% chance of being higher than the average of 12°C to 18°C) for February 2026. Rainfall is likely to be average (1mm to 10mm for February).

NOTE re unfavourable weather conditions: Under these conditions a high percentage of adult Qff find refuge until more favourable conditions return. However, a high proportion of immature stages (eggs and larvae and, to a lesser extent, pupae) are killed off by hot, dry weather. Unless controlled by consistent farm and community management the adult Qff in refuge can then feed a late summer/early autumn Qff population explosion – which coincides with the bulk of commercial crop ripening.

Fig. 4. Actual and forecast temperatures for Shepparton for January 2026 (https://www.visualcrossing.com/weather/weather-data-services – accessed 8 January 2026).

Fig. 5. Actual and forecast relative humidity and rainfall for Shepparton for January 2026 (https://www.visualcrossing.com/weather/weather-data-services – accessed 8 January 2026).

Fig. 6. Chance of above median rainfall for February 2026

Fig. 7. Chance of above median maximum daily temperature for Feb 2026

Fig. 8. Chance of above median minimum daily temperature for Feb 2026