Ongoing research into Queensland fruit fly control
Researchers are taking a multidisciplinary approach to address the management of Queensland Fruit Fly (QFF).
This page is an overview of QFF research conducted by Agriculture Victoria.
Improved traps targeting female flies
Fruit fly traps contain attractant odours that lure adult flies into a trap and then kill them using an insecticidal bait. Commercially available fruit fly traps either contain the synthetic odour “cue-lure”, which strongly attracts adult male QFF, or they contain a protein-based attractant (usually based on yeast) that attracts both sexes, but predominantly virgin (unmated) adult female flies. New lures have now been developed that are based on fruit-odours and target mated female QFF, which directly damage fruits by “stinging” fruits to lay their eggs.
Agriculture Victoria’s new female fruit fly lure
Agriculture Victoria’s research scientists at AgriBio have developed a novel female QFF attractant based on a mixture of odours produced by ripening fruits and microbes (yeasts) involved in fruit fermentation. The new lure is placed inside a sticky trap that is a fruit mimic (see picture) and has shown considerable promise in field trials, attracting significantly more mated female flies than protein-based attractants and another commercial “fruit odour” lure.
Mass trapping fruit fly in table grapes
A recent project has been exploring the development of a mass trapping strategy for QFF in table grape vineyards. The project trialled Agriculture Victoria’s newly developed “mated female” fruit fly trap (see above) and looked at possible scenarios and strategies for mass trapping, including placing traps throughout the whole block, around the perimeter, and / or in host trees and refuge sites. Results showed that perimeter trapping might be the most cost-effective system for table grapes, but also revealed QFF preferences for different grape varieties, and problems with using the current fruit-mimic trap design (a sticky trap) in and around Mildura where there are frequent dust storms.
Parasitoids for biological control of QFF
Biocontrol – the use of natural enemies (often called “beneficial insects”) to manage pest populations – is a crucial component of integrated pest management (IPM) and area-wide management strategies to control insect pests. However, for the Australian pest fruit flies, surprisingly little work has been carried out to explore the potential for biocontrol in fruit fly management. The Agriculture Victoria research team has been exploring the use of parasitic wasps, or parasitoids, as biocontrol agents against QFF. The aim is to try and establish these key predators, which only attack fruit flies, in the state. Two fruit fly parasitoid species were collected from Queensland and Northern NSW and mass cultured at Agriculture Victoria’s Tatura SmartFarm. 95,000 parasitoids have been released across Victoria, predominantly in rural towns and cities where fruit flies can be problematic to manage. The research has shown encouraging signs that the parasitoids will establish and help control fruit fly populations, but further work is required to see whether these key predators can survive the chilly Victorian winters and hot dry summers.
Biopesticides against QFF
Biopesticides are natural pesticides based on microorganisms or their products. This new generation of environmentally friendly IPM tools can be targeted and highly effective at controlling a wide range of insect pests. Agriculture Victoria have been investigating the use of insect killing (entomopathogenic) fungi (EPF) as prospective biopesticide agents for Queensland fruit fly, in particular at targeting the larval stages that bury into the soil to pupate. The research has involved isolating naturally occurring EPF from the soil and screening these against different life stages of the fly. A number of highly effective species and strains of EPF have been identified in the lab studies, and the research is now testing these in conditions that are more similar to the field.
Rapid insect diagnostics
Agriculture Victoria Research have been developing and evaluating new molecular technologies for improving fruit fly diagnostics.
A technique known as metabarcoding has been developed that enables simultaneous identification of multiple fruit fly species in a single batch. Metabarcoding identifies insects using DNA sequences and is suitable for processing large trap samples of fruit flies. This will help with fruit fly surveillance, particularly in northern Australia where a high diversity of species and many thousands of insects may be caught in traps each week.
Agriculture Victoria Research have also developed metabarcoding technology as a surveillance tool for Spotted-wing Drosophila (SWD), a high priority exotic fruit fly pest that attacks ripening fruits, particularly berries. Current SWD traps catch large numbers of non-pest drosophila fruit fly species, which must then be individually visually examined to ensure they are not SWD. Research has focused on developing metabarcoding for rapid identification of insects in “bulk” trap samples, paving the way for new cost-effective surveillance programs for this and other highly destructive pests.
Further development has also been underway of a new portable technology that can accurately identify fruit fly species. The technology is called LAMP (loop mediated isothermal amplification) and can be used to quickly identify fruit fly eggs, larvae, and adults. Agriculture Victoria researchers have extended the range of LAMP tests available for identifying fruit flies, which can now identify major fruit fly pests including QFF and Medfly, high priority exotic pests such as SWD and the oriental fruit fly,as well as the lesser endemic pest (e.g. Jarvis’ fruit fly), and non-pest fruit fly species (such as Island fly).
New genomic tools
Agriculture Victoria Research have started exploring the use of genomics for understanding genetic relationships between fruit fly pest populations, beginning with QFF. These approaches show potential for ‘tracking and tracing’ invasive flies at the critical early stages after an outbreak is detected, providing valuable information on their population size, movement, and introduction pathway. Future research, studying other fruit fly genomes, will assist with developing new diagnostic tools and reveal the genetic mechanisms invasive species use to establish in new regions and fruit hosts, opening the door for new approaches to attract and exterminate these destructive pests.
Sterile insect releases in Cobram
Staff at Agriculture Victoria’s Tatura SmartFarm have been involved in a national project that is developing Sterile Insect Technique as a tool for fruit fly management. Sterile QFF produced in a factory in South Australia were transported in the pupal stage to the SmartFarm where they were reared to mature (sterile) adult stage in a specially designed facility, before aerial release over a study area in and around the regional town of Cobram.