AHDB-funded student Emily Forbes is undertaking PhD research on Utilising the patchy distribution of slugs to optimise targeting of control; improved sustainability through precision application.

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 it 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, alternative methods of targeting are being investigated to reduce the amounts of pesticide required to efficiently control slugs. It is widely recognised that the grey field slug has a patchy distribution in arable crops, this combined with currently available technology which allows precision application could provide the answer.

Emily uses RFID tags injected into individual slugs to track their movements and uses this data to devise mathematical models to help understand patch formation. So far, she has found that slugs appear to have a ‘home range’, returning to the same places for foraging and shelter. They also rely on the slime trails of other slugs to navigate. Interestingly however, the position of these slug patches does not seem to match the areas of crop damage.

It is hoped that these findings will lead to new ways to target control measures at slug patches and therefore reduce the amount of pellets required for protection of the crop.

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”.