*EASTBIO* Slug viruses for biocontrol: diversity, host range, and metagenomic discovery

Slugs (and to a lesser extent, snails) are a perennial problem in crops across the arable and horticultural sector. Crops such as oilseed rape (up to 59% of the UK cropping area) and wheat (up to 22%) are significantly affected by pests such as the grey field slug (Deroceras reticulatum). The AHDB estimates that untreated, slug damage would cause losses in oilseed rape of £18M pa, £25.5M in wheat, and £53M in potatoes. Even with molluscicides, the loss to slugs in vegetables is estimated to be upwards of £8M a year. Approaches for slug management have not progressed appreciably since the introduction of molluscicide pellets several decades ago. However, these are now being revoked (methiocarb in 2015), or are under threat (due to metaldehyde contamination of drinking water catchments). Consequently, novel approaches for integrated slug management are required to safeguard metaldehyde for future use, and to utilise other available options. A biological control method that is suitable for integrated pest management is therefore highly desirable.

Viruses have been successfully used to control insect pests such as moths. However, they have not been explored or advocated for the control of molluscs. In part, this may reflect the general lack of basic research in mollusc virology, pathology, and immunity – at least as compared with insects.

However, advances in virus discovery are revolutionising our understanding of the viral diversity of molluscs, and provide an exciting opportunity to reassess viruses as a potential agent for mollusc control and to better understand their antiviral immune system. This proposal will use metagenomic sequencing to identify viruses naturally infecting wild gastropods, and characterise the diversity and distribution of viruses across pest and non-pest species in the UK.

In parallel, we will attempt to isolate at least one virus by gradient centrifugation, and characterise its pathology. In combination, the approaches will (i) characterise the virus community of the pest and non-pest gastropod community, and (ii) attempt to isolate viruses for future experimental work and/or development as biocontrol agents.

This project would suit anyone with an interest and background in virology and or virus diversity.