Case study 1 – Targeted control of slugs

AHDB-funded PhD student Emily Forbes is looking at the patchy distribution of slugs and the potential to target control with precision techniques.

The grey field slug (Deroceras reticultaum) is the most economically important slug species for the UK agricultural industry. It has been estimated that without effective controls, slugs could cost the industry in the region of £100 million per year.

With increasing pressure to reduce pesticide use, and the removal of methiocarb from the market and the pending ban of outdoor uses of metaldehyde, alternative methods to target slugs are required.

Applying slug pellets evenly across a field may become a thing of the past, if the patchy distribution of the pest can be better understood. AHDB-funded PhD student Emily Forbes has been working for the last three years to map the presence of slugs in commercial fields. The research uses innovative tagging technology, where a harmless device (about the size of a grain of rice) is attached to slugs to detect where they congregate and how and when they move about the field (even when they are under the ground). Emily looks at the patterns and influence of environmental factors (eg soil moisture, organic matter, pH and soil type) to develop approaches for precision treatment. The work could reduce the amount of control product required and increase the economic viability of non-metaldehyde options.

Mike Casswell, Sycamore Farm

Slugs are an issue for us as we have fields on the farm that have a heavy clay content where obtaining firm fine seedbeds can be a challenge. We also grow oilseed rape which unfortunately provides a good environment for slugs to proliferate. A concern for me is the loss of actives such as Methiocarb and the seed dressing Deter. I consider Emily’s research vital if we are to continue to grow crops that are vulnerable to slug pressure. We must learn ways of obtaining improved cultural control, understand better their habits and utilise new technology to provide more targeted applications”.