qld.gov.au
Department of Primary Industries

Fruit fly is the biggest single risk to Australia’s horticultural growth and export.

Fruit fly infestation can affect productivity and disrupt access to both domestic and international markets. Many international markets require evidence that horticultural products are free of fruit flies and have received agreed phytosanitary treatments to ensure they are free of pests and disease.

Fruit fly is spreading into regions where it was previously absent, creating a growing risk to Australia’s horticulture industry.

In response, our Market Access team is conducting research into fruit fly disinfestation and phytosanitary treatment. We’re conducting research across a wide range of temperate, sub-tropical and tropical fruit and vegetables to help growers access new export markets and maintain their trade with existing markets.

The outputs from this research will benefit industry through:

  • new international trade pathways
  • expansion of existing international trade pathways
  • regulatory cohesion internationally
  • access to alternative phytosanitary treatments for domestic trade
  • a better understanding of fruit flies in Australia and around the world.

Using irradiation before export

Fruit and vegetable exports are increasingly important for Queensland’s farmers. But importers want produce that is guaranteed to be free of pests and disease.

Irradiation is one of the best methods of phytosanitary (pest and disease) treatment currently available. It’s a chemical-free treatment that leaves no harmful residue on the produce and doesn’t release anything that could be harmful to the environment.

Until recently, Food Standards Australia New Zealand (FSANZ) had approved irradiation for use on 26 different commodities.

On 22 July 2021, FSANZ introduced a new provision that allows irradiation for phytosanitary purposes on all fresh fruit and vegetables grown in Australia and New Zealand. The new provision was based on an application from our Market Access Team, using data collected through our research.

Australian quarantine laws mean that food grown in an area with known pests must be treated before it can be sent to another quarantine region—either domestically or internationally. Most fresh produce sold in Australia and New Zealand is grown and eaten within the same quarantine region, so no treatment is needed. But exports usually require phytosanitary treatment, and that’s where irradiation comes in.

International standards that specify dose rates are already in place for irradiation treatments. For example, the standard treatment for fruit flies is 150 Grey (Gy), while a generic treatment of 400 Gy is approved for all insect pests (except a small number of Lepidoptera).

The new FSANZ approval provides an alternative phytosanitary treatment option for growers in Australia and New Zealand. It enables growers to choose the treatment that best suits their crop and business model.

Using irradiation pathways also provides insurance against pest incursions. For example, the recent detection of pests such as serpentine leaf miner initially resulted in state-based market access restrictions. Because generic irradiation approvals were in place and FSANZ approval granted, these markets reopened. Read the FSANZ Approval Report (PDF, 306.83 KB).

Predicting and preventing fruit flies in Australia

Fruit fly presents the biggest single risk to Australia’s horticultural industry. Fruit fly infestation affects productivity and can create a regulatory barrier to trade.

A major fruit fly project—The Phenology, demography and distribution of Australia’s fruit flies—was designed to provide current, comprehensive scientific and technical information about fruit flies across Australia. The project finished in late 2022, and its outputs underpinned fruit fly regulation and management, guided in-field management, and supported domestic and international trade protocols.

The project focused on 3 broad issues:

  • the seasonal cycles that affect fruit fly activity (phenology)
  • fruit fly reproductive patterns and population changes (demography)
  • fruit fly locations (distribution).

The project improved our understanding of the fruit fly in order to develop predictive models in the future to help with long-term planning and industry sustainability.

Most previous fruit fly research in Australia has been conducted in constant temperature conditions, which limits its real-world application. However, in this project, we conducted experiments over a range of temperatures (for day-degree temperature models) and on different host species, focusing across all life stages of key Australian pest fruit fly species.

The data collected in our research have improved the phenological day-degree models used to predict fluctuations in fruit fly populations. For example, improved models will be used to better guide pest management—including calculating when fruit fly infestations will start and calculating reinstatement dates after outbreaks.

For more information about our research:

Securing nectarine and peach exports to China

Since 2016, Australian nectarines and peaches have been sold in China. This market was secured through a market access protocol based on research conducted by the Market Access team. The new trade pathway was announced on 20 May 2016 by the former Australian Government Department of Agriculture, Water and the Environment.

This new market access protocol allows for air freight export to China of both nectarines and peaches.

Annual export of nectarines and peaches to China is currently estimated at $37.7 million, roughly half of which is exported using the air-freight pathway based on data generated by the team.

Under the protocol, nectarines and peaches exported to China by air freight are fumigated with low-dose methyl bromide. Low concentrations of fumigant are applied over a long treatment time, without compromising fruit quality. The low concentration of methyl bromide also addresses environmental concerns. This provides quarantine disinfestation treatment against Bactrocera tryoni, the Queensland fruit fly.

This protocol was based on 3 large-scale trials conducted in Queensland between 2013 and 2016. The research examined the 4 immature life stages of the Queensland fruit fly (eggs plus first, second and third instar larvae) in both nectarines and peaches. Research met international quarantine standards—testing against more than 30,000 individuals of the pest species, with no survival. This equates to an efficacy of less than 99.99% mortality at the 95% confidence level. Our research met these requirements.

The market access protocol for exporting nectarines and peaches to China was the first international protocol using low-dose methyl bromide—pioneered by the Market Access team, then negotiated by the Australian Government Department of Agriculture, Fisheries and Forestry.

Read more about the protocol and the research that informed:

Understanding fruit flies around the world

Fruit fly isn’t just a problem in Australia. Throughout the Asia Pacific region, the fruit fly causes extensive crop damage. We have worked with partners in Indonesia and the Philippines to understand more about fruit fly control.

A recent project used an area-wide management systems approach (AWM) to control fruit flies in areas as small as 25 hectares. Management activities included male fly annihilation, protein baiting and sanitation. The research began in 2018, in Indonesia, and was completed in 2024. Within only 6 months, fruit fly populations and fruit infestation in the treated zones were negligible.

Since 2019, losses from fruit flies have reduced markedly in participating farms—from almost 70%, to less than 0.2%. The research has brought benefits to smallholders and larger mango farmers across the Asia Pacific region. In addition, reducing these fruit fly populations reduces the risk of exotic fruit flies entering Australia. That’s a win for us.

The technology needed for AWM is available to Indonesian farmers, but a plan for either importing or locally producing the protein bait is needed to secure long-term adoption. The technology may also be viable for other commodities in the Asia Pacific region, based on the production and supply of protein bait.

A comprehensive manual was produced that presented key concepts, principles, steps and techniques, to help growers, extension officers, researchers and communities in tropical and subtropical regions to manage fruit fly infestation.

More information

Last updated: 30 Jul 2025