'Riding the slime wave' might not be the most enticing of subjects, but Dr Jenna Ross, has certainly made it a bit more consumable following the publication of her Nuffield Farming scholarship report of that title.

Dr Ross was sponsored by the Royal Highland and Agricultural Society of Scotland (RHASS) and the Agricultural and Horticultural Development Board (AHDB) Cereals and Oilseeds as part of her scholarship.

Here we have a few of her key findings from her visits to Australia, Belgium, Brazil, Canada, Japan, Kenya, New Zealand, Norway, United Kingdom, South Africa and Spain ...


Slugs are one of the top agricultural and horticultural pests in the UK and current methods for control rely on molluscicide pellets containing either metaldehyde or iron (ferric) phosphate.

But in December, 2018, Defra made the decision to ban the outdoor use of metaldehyde due to its impact on birds

and small mammals, but in July, 2019, the High Court overturned the ban, ruling that the decision-making process by former Defra secretary, Michael Gove, was unlawful.

With such uncertainty over the future of metaldehyde, there is now a greater reliance on alternatives, such as ferric phosphate, biorationals, biologicals, physical barriers and agronomic/cultural practices.

In addition, there are also concerns over biological invasions, especially relating to the Spanish slug, arion vulgaris, which is a major agricultural pest across Europe.

This project aimed to collate global information on slugs and their various control options in order to enhance farming methods. Objectives were to characterise key slug species in the UK; identify potential slug invasions and their impact on biosecurity; determine direct and indirect economic risks of slugs; review slug monitoring systems; evaluate slug control options; determine the future of malacology; and to investigate novel commercial applications for slugs.

My conclusions include the fact the more than 50% of slug species are exotic in the UK, so it is imperative that biosecurity protocols are developed to prevent further mollusc invasions.

Also, slugs have a direct economic impact on crop damage, as well as an indirect impact on human and animal health, rejection of exported crops and soil health (through slug control strategies).

There is a drive to incorporate technology into slug monitoring systems, though with uncertainty over metaldehyde, ferric phosphate may be the only ‘chemical’

control option available in the future, as many of the current nematode bio-molluscicides are not feasible in broadacre crops due to cost, the volume of water required, storage and shelf life.

Agronomic and cultural practices are playing an increasing role in controlling slugs, and so farmers should consider a slug IPM strategy pyramid, that should be tailor-made to each

field. However, the study of malacology appears to be in difficulty, with no clear succession plan in place, and limited funding available to share and develop ideas.

Perhaps we are missing an opportunity and we should be farming slugs instead, targeting slugs and their bi-products towards the food, cosmetic and pharmaceutical industries?

Recommendations for National Strategic Action:

• Conduct a systematic survey to better understand the slug fauna of the UK.

• Implement biosecurity protocols to prevent future biological invasions of exotic slugs into the UK.

• Employ an eradication protocol for the Spanish slug, A vulgaris.

• Make changes to regulatory system to speed up registration process for new molluscicides.

Industry and research:

• Calculate the monetary value of direct and indirect impact of slugs.

• Develop real-time mobile monitoring and treatment systems for slugs.

• Investment into the development of new and current chemical, biorational, physical barriers and biological control methods.

• Develop a system to deliver a slug IPM strategy pyramid that is tailored to each field.

• Scientists should work alongside farmer groups to translate scientific findings into practical outputs.

• Investigate opportunities for farming slugs for the food, cosmetic and pharmaceutical industries.