Auto-dissemination of entomopathogenic fungi for sustainable control of spotted wing drosophila, an invasive pest threatening the future prosperity of the UK horticulture industry

"The UK fruit industry is under continual pressure from introduction of non-native pests and diseases. Spotted wing drosophila (SWD), _Drosophila suzukii_, was first detected in the UK in 2013 and populations have increased year-on-year since then. The pest lays eggs in fruit before ripening and the larvae destroy the fruit from the inside, so the damage is only detectable after harvest. Fruits attacked in the UK include raspberry, strawberry, blueberry, blackberry, cherry and grapes and 25-100% of strawberry and cherry crops were lost during 2016\. The value of UK horticulture production is £400 m pa, and an estimated £20-30 m pa is currently spent on controlling the pest. Equivalent losses and costs are experienced in the US and other European countries where SWD has established. Best practice approaches include rigorous removal and destruction of waste fruit and use of insect mesh barriers. These are costly and growers still revert to routine pesticide applications to prevent economic damage. This strategy is not sustainable. Consumers increasingly demand produce free of insecticide residues and it is vital to prevent emergence of insecticide resistance in the pest. Furthermore, the need to use chemical insecticides against SWD is compromising the impressive programmes of integrated pest management that growers have developed against other pests and diseases.

This research project will provide the basis for development of new products for control of SWD in a sustainable manner, compatible with integrated pest management. The product will use novel lures to attract the flies to a device which infects them with a new strain of fungus which is highly pathogenic to the flies but not to other organisms. The infected flies are released and the fungus can be passed on to other flies before killing the infected individuals, thus greatly enhancing the impact of the initial infection in a way not possible with other products.

The commercial partners are the leading UK producer of biorational pest control agents and the UK's foremost berry and stone fruit production and marketing group. The academic partners are two research institutes with long experience in research on insect attractants and management of SWD. This will ensure timely delivery of research outputs which are suitable for commercial production and acceptable to growers. The research will provide the basis for development of at least three new products with worldwide market potential and their use will increase productivity and profitability of the UK horticulture industry."