Innovative methods of controlling fruit flies – and limiting the damage they can do the soft fruit industry – have been identified by a major EU-funded project.

Coordinated by Fera (formerly the Food and Environment Research Agency) the DROPSA project was set up to develop effective, integrated solutions to the control of pests and diseases.

Based near York, UK, Fera is a private and public sector joint venture which works with the private sector, UK government departments and other public bodies, plus governments in other countries and international organisations, to innovate and develop translational science that will protect and enhance food, plant and environmental quality.

As part of this recently completed four-year project, a consortium led by Fera’s Dr Neil Audsley investigated a variety of means of managing the fruit fly, Drosophila suzukii, commonly known as spotted winged Drosophila (SWD) . This is an invasive pest which poses a significant threat to the global soft fruit industry and can cause major damage to fruits such as strawberries and cherries. It has not been possible to eradicate or contain this pest and control with conventional pesticides is difficult because it infests ripening fruit during the pre-harvest period when pesticides cannot be applied.

SWD can also survive at low temperatures (-5°C) and it has a very large host range. The fly attacks both horticultural crops, such as soft fruits, and wild fruits – which are present in woodland and hedgerows. These wild areas can’t be indiscriminately sprayed with pesticide, which means that an area control strategy – such as biological control – is required.

Fera’s research identified biological control agents and novel methods which disrupt fly physiology and behaviour, as a means of combatting the threat from SWD. Using laboratory trials, Fera also identified the most effective synthetic insecticides in controlling SWD, which were then evaluated in field trials in Italy by other partners.
Through its work on the DROPSA project, Fera targeted key components neuropeptide hormones and their associated G-protein coupled receptors, which are responsible for regulating essential fly physiology and behaviour, such as reproduction and development. Disrupting the normal function of these hormones and receptors will result in an inappropriate physiological response and ultimately death. This approach may be developed to specifically target the Drosophila suzukii fruit fly without killing non-target beneficial species such as bees.

Fera identified that Entomopathogenic fungi could infect and kill adult flies, reducing fruit fly populations. Although not 100% effective, used in combination with other control options, this could provide a useful tool in an integrated pest management strategy. In addition, the use of Entomopathogenic fungi is a more environmentally beneficial control method than that offered by synthetic pesticides.

Fera is also investigating the potential of using parasitic wasps to attack SWD.

Dr Neil Audsley, project co-ordinator for DROPSA at Fera said: “The success of the DROPSA project is an example of how Fera is applying internationally recognised scientific expertise in order to tackle industry challenges.

“It’s vital that we develop new, innovative solutions which can tackle the threat of pests such as SWD and ensure food security now and in the future. It is estimated that fruit losses from pests and pathogens accounts for over €10 billion in revenue and three million tonnes of produce to the EU fruit industry.

“The DROPSA project has armed us with four years of in-depth research and specialist expertise. This can help the soft fruit industry enhance its integrated pest management (IPM) strategies, take on the challenge of emerging pests and minimise the economic damage that can be caused by invasive species.”

The DROPSA project saw Fera and 25 partners across Europe, North America, Asia and New Zealand examine potential chemical, biological, cultural, integrated and novel pest and disease control strategies.

In addition to focusing on SWD, the DROPSA project investigated methods of control of pathogens including Pseudomonas syringae pv. actinidiae, Xanthomonas fragariae and Xanthomonas arboricola pv. pruni which are also a major threat to fruit production. The DROPSA project identified and evaluated biological control agents (BCAs), resulting in two potential candidates (Lactobacillus plantarum and Bacillus amylioliquefaciens) that are being developed as novel microbial pesticides. The project also identified a novel antimicrobial peptide, which is biodegradable with very low toxicity, which was effective at controlling kiwifruit, peach and strawberry pathogen infections.

The DROPSA project provided recommendations to the soft fruit industry to improve current practices and has evaluated both chemical and non-chemical methods of managing pests and pathogens, such as the used of nets to protect fruit from flies, pruning diseased plants and removing and destroying fruit after harvest.

Fera employs 300 scientists at the National Agri-food Innovation Campus near York, UK. It is helping to turn scientific excellence into economic impact across the food industry by bringing its experience to a range of high potential EU research and innovation projects, focusing on Crop Health, Next Generation Diagnostics, Food Integrity and Sustainable Agri-food Systems.

Its work on EU-funded projects such as DROPSA is underpinned by extensive facilities and more than 100 years of heritage in world class science, and demonstrates its ability to effectively collaborate on a national and international basis with the private sector, government departments, international organisations and other public bodies.

For more information on the DROPSA project, visit

Pictured: Pests such as SWD can have a major impact on soft fruit production