A NSW Government website

Oriental fruit fly

Changes in oriental fruit fly climate suitability are likely to create challenges for the horticultural industries.

Oriental fruit fly in NSWQueensland fruit fly is found in the eastern half of NSW: primary industries in this area would also be threatened by oriental fruit fly. There is a Fruit Fly Exclusion Zone in the south-west of the state, extending into Victoria and South Australia.

The exotic pest oriental fruit fly (Bactrocera dorsalis) is one of the most destructive horticultural pests in the world, with a reported host range of over 400 types of fruits and vegetables. Fruit flies cause damage by laying their eggs in the flesh of fruit and vegetables, which the resulting larvae consume. This damages the interior of the produce and may cause it to fall to the ground. Oriental fruit fly is one of very few fruit fly species that will infect some immature fruit. The key oriental fruit fly life stages include egg, larvae, pupae and adult.

There is not currently an established population of oriental fruit fly in Australia, but it is found on Christmas Island. The map shows the endemic distribution of Queensland fruit flies across western (yellow) and eastern (brown) regions in NSW. Locations affected by Queensland fruit fly act as proxies for the area of concern for Oriental fruit fly. Locations indicate trapping sites for fruit fly surveillance.

Oriental fruit fly is also established in Papua New Guinea, and there is potential for it to be accidentally introduced into Australia via infested produce, soil or sand. The Australian Government collaborates with state and territory governments to operate the National Exotic Fruit Fly in Torres Strait Eradication Program, aimed at protecting Australia from exotic fruit fly incursions. An incursion in Queensland in the late 1990s was successfully eradicated, but at a cost to industry of $100 million and taking four years. It has been estimated that if oriental fruit fly becomes established in Australia, the cost to the produce industry would be $2.1 billion annually.

The current range of Queensland fruit fly in NSW and locations of interest for that pest are used as proxies for areas of interest for an incursion of oriental fruit fly into NSW because both pests threaten the same horticultural industries.

What is the NSW DPIRD Climate Vulnerability Assessment? ⏷

Climate change is altering the biosecurity risks for many agricultural commodities across NSW. Primary producers need evidence-based information about the changing climate, and the risks and opportunities it may bring.

The NSW DPIRD Climate Vulnerability Assessments are enhancing the resilience of our primary industries by providing information and data to help the sector better plan for, and respond to, climate change. They have assessed climate change impacts for extensive livestock, broadacre and irrigated cropping, marine fisheries, forestry, horticulture and viticulture, and important biosecurity risks associated with these industries to inform sound planning, risk management and adaptation decisions.

Learn more about the Climate Vulnerability Assessment.

How we assessed climate suitability ⏷

Climate projections were sourced from Climate Change in Australia’s ‘Application Ready Data’. This dataset is comprised of projections from an ensemble of 8 global climate models, each presenting a plausible future climate. Low confidence in the projected changes due to differences between the models is noted in the text. Care should be taken when interpreting these results.

The Climate Vulnerability Assessment is intended to highlight potential industry- or regional-level changes. Intermediate and high emissions scenarios were used in the assessments (RCP4.5 and RCP8.5), but these are not the only future scenarios possible. The inclusion of climate variables important to the commodities production was based on published research, expert knowledge and data quality and availability.

Climate suitability was assessed on a monthly timescale, with the reported climate suitability representing the average for a given month over all years in the dataset. This reflects the pattern of life stages for oriental fruit fly and the need to determine which months are likely to pose the greatest risk to host commodities.

Learn more in the Climate Vulnerability Assessment Project Framework.

Climate impacts: expected challenges for primary industries

Regions where oriental fruit fly could survive (if they were present) are likely to maintain or increase their climate suitability to high or very high suitability by 2050 under both emissions scenarios.

Changes to overall monthly climate suitability affect oriental fruit fly in NSW in different ways:

  • April to November – there are likely to be minimal to moderate increases in climate suitability in the eastern and western regions. The increases are likely to be greatest under the high emissions scenario (moderate to high confidence).
  • December to February – there are likely to be minimal to moderate decreases in climate suitability in eastern and western regions. The decreases are likely to be greatest under the high emissions scenario (low to high confidence).
  • March – there are likely to be minimal increases in climate suitability in only the eastern region. The increase is likely to be greatest under the high emissions scenario (moderate to high confidence).

Should an incursion occur by 2050, the NSW climate is unlikely to restrict year-round survival of oriental fruit fly. Milder winters with higher minimum and mean temperatures may allow survival of oriental fruit fly through the colder months in warm, protected areas. This persistence through winter may increase the risk of an incursion transitioning to an endemic population in NSW.

The effects of an oriental fruit fly incursion on horticultural industries in NSW will depend on:

  • the future distribution of those industries,
  • changes in production timings, and
  • the overlap between susceptible life stages of commodities and the reproductive stages of the oriental fruit fly lifecycle.

Due to the large number of potential hosts, industries will need to consider broad reaching oriental fruit fly education programs to raise awareness of the risks and management strategies.

Where can I find the climate suitability maps?

Maps of historical and future climate suitability for commodities were produced to demonstrate where in the state a commodity is likely to thrive or else be limited by future climatic conditions. The maps are not provided on these webpages but can be found in the Climate Vulnerability Assessment Summary Report  (PDF, 41425.92 KB).

Oriental fruit fly Factsheet

(PDF, 362.26 KB)

Summary Report

(PDF, 41425.92 KB)

Related Climate Vulnerability Assessments

Contact us

For more information please email: vulnerability.assessment@dpi.nsw.gov.au