History of spread

Early distribution and origin — QFF is native to eastern Australia, historically centred on tropical and subtropical Queensland and nearby coastal zones.

• 20th century inland and southward expansion — throughout the 1900s QFF expanded from its Queensland strongholds into adjacent parts of New South Wales and into southern temperate regions during favourable years, driven by the movement of infested produce and expanding suitable habitat.

• Establishment in Victoria and intermittent incursions elsewhere — by late 20th and early 21st centuries, QFF had seasonal or established populations in parts of Victoria and occasional detections in South Australia and the Northern Territory; climatic suitability and local outbreak events have allowed persistence in new pockets and seasonal incursions into previously low‑risk areas

• Recent range shifts and modelling evidence — contemporary surveillance and climate‑vulnerability modelling show increasing climate suitability further south and inland in Australia, raising the risk of more frequent outbreaks and longer activity seasons in regions that were previously marginal for QFF.

• Research and management responses — national research programs and state biosecurity agencies have focused on improved phenology models, area‑wide management, surveillance and export phytosanitary protocols to manage spread and reduce market impacts.

Economic impact

The economic impact of Queensland Fruit Fly (QFF) causes direct production losses and reduced marketability that amount to millions of dollars each year for Australian growers and supply chains, where outbreaks increase surveillance, control and compliance costs for governments and producer groups, and can threaten export market access with additional economic consequences:

• Crop losses from fruit rendered unsaleable.

• On‑farm control costs (baiting, insecticides, monitoring).

• Area‑wide management and eradication expenditures (surveillance, quarantine, SIT trials).

• Market access and compliance costs when outbreaks constrain exports or require extra phytosanitary measures

Behaviour

Life cycle and development: Adults emerge from pupae in soil and live as flying, feeding insects; development passes egg → larva (maggot) → pupa → adult, with the soil pupal stage commonly lasting about 10 days under warm conditions and lengthening in cooler weather.

Seasonal activity and phenology: QFF activity is seasonal: adults become active in late winter–spring as temperatures rise, populations build through late spring and summer when hosts are abundant, activity declines in autumn, and many flies overwinter as adults in sheltered sites or as pupae in soil or fallen fruit during mild winters.

Reproduction and fecundity: Females sting fruit to lay eggs and can lay large numbers of eggs (dozens to about 100 per day under favourable conditions), producing successive generations that cause rapid population increases when hosts and temperatures permit

Dispersal and movement: Short‑ to moderate‑distance dispersal occurs by adult flight between host trees, orchards and gardens; long‑distance spread is driven by human movement of infested fruit and produce, enabling jumps beyond natural flight range and seeding new outbreaks.

Host use and feeding behavior: Adults feed on sugars from ripening fruit, nectar and plant exudates, while larvae feed inside fruit, causing internal damage that often leaves external fruit appearance deceptively normal; QFF attacks a wide range of fruit and fruiting vegetables and shifts hosts as different crops come into season.

Behavioural traits relevant to control: QFF are attracted to protein and cue‑lure baits used in monitoring and suppression; females respond to protein baits for feeding and oviposition cues, making baiting, trapping and exclusion (netting, fruit bagging) effective parts of integrated control when applied consistently and early in the season.

Diet

Their diet includes 100+ fruits and many vegetables. Home gardeners list

Blackberry infestations, abandoned/unmanaged fruit trees and movement of infected produce are a high-risk breeding cycle source

Queensland fruit fly adults feed on sugary resources for energy and on protein sources to mature eggs, while larvae feed inside host fruit on the fruit pulp and juices.

• Sugars and carbohydrates: adults feed on nectar, honeydew, sap and surface sugars on ripening fruit to fuel flight and daily activity.

• Protein and nitrogen: adults, especially females, seek protein sources (decaying matter, bacterial films on fruit and leaves, protein baits) to develop eggs and increase fecundity.

Adults will take small droplets of protein or sugar from foliage and trunks where baits are applied, making bait sprays effective because flies forage on leaves and tree trunks.

Reproduction Lifecycle

A Queensland fruit fly (QFF) life cycle takes about 4 weeks in favourable conditions (warm temperatures and high rainfall and humidity), but longer in cool, dry weather (Figure 2). The adult population reduces in winter, with some inactive adults surviving by sheltering (over-wintering) in protected areas.

1. Adult female flies lay eggs in batches of up to 12 by stinging ripening fruit. Eggs hatch in 2–3 days

2. Larvae begin feeding on the fruit. The larvae (maggots) are fully grown in about 10 days and emerge by ‘flicking’ from the fruit to pupate in the soil.

3. Pupation lasts about 10–20 days

4. QFF is a very small fly approx. 7-9mm. The adult fly emerging to feed on water, protein and sugars. Female flies mate once, while male flies can mate many times. If a female has fed on protein, she begins laying eggs 7–20 days after emerging from the soil. A single QFF can lay up to 2,000 larvae in her lifecycle.  Adult flies can live from weeks in the summer, up to months over winter.