A slug expert in Norwich is urging people to stay vigilant against the invasion of the Spanish slug – dubbed the 'giant killer slug' – and to help with on-going research.

Eastern Daily Press: Dr Ian Bedford, head of entomology at the John Innes centre, with the juvenile Spanish 'killer' slugs which have appeared in gardens in the warmer weather. Picture: Denise BradleyDr Ian Bedford, head of entomology at the John Innes centre, with the juvenile Spanish 'killer' slugs which have appeared in gardens in the warmer weather. Picture: Denise Bradley (Image: Copyright: Archant 2013)

Known as the arion vulgaris, these types of slugs hit headlines across the country in 2012 after being discovered by scientists in the city and have made a comeback following warnings earlier this year. Ian Bedford, head of entomology at the John Innes Centre, based near the Norfolk and Norwich University Hospital, first found the slugs here in East Anglia in 2012 and sent them to a colleague in Aberdeen to be identified.

He and others were finding thousands of the species in their gardens, prompting the creation of the website www.slugwatch.co.uk for people to report sightings and get help.

'Feedback from the website has seen that a lot of people are telling us that they have found one or two in their gardens,' Dr Bedford said.

'But what we are looking for now is people letting us know if they are picking up hundreds of Spanish slugs, so that we can make a note of their postcode.'

The slugs started to re-emerge in April last year, but a cold snap killed them off, stopping them from any further breeding.

However, this year's weather has been much better for them, with Dr Bedford warning they could return in numbers similar to 2012.

Dr Bedford, who lives in Norwich, is having to dispose of between 30 and 40 and day.

'We have people around Norwich reporting collecting between 3,000 to 4,000 a month.'

The slugs, which can grow up to 15cm long and lay between 200 and 400 eggs, feast on dead animals – as well as meat, plants and dog excrement – and can eat up to 20 slug pellets before they start to die.

Dr Bedford and other scientists at the John Innes Centre are waiting to hear if they have secured grants to carry out more research into the species.

What to do with the slugs if you find one

It can sometimes be difficult to confirm a Spanish slug but one thing Dr Bedford and his team do not advise is cutting the slugs in half, as is commonly done.

'If there are pets or children around they could ingest bacteria from inside the slugs if you cut them in half,' he said.

'The best way to get rid of them is to collect them, using gloves or a piece of wood, and put them in a bucket of water. Add a bit of detergent and that will be enough to make them sink to the bottom. Then dispose of them by digging a deep hole in the garden, but make sure you disinfect or bleach the bucket afterwards.'

As part of on-going research, Dr Bedford is urging the public to help the team to understand the extent of this 'invasion of the Spanish Slugs' and participate in Slug Watch by surveying the slugs in gardens, school grounds and the general area and to report any observations to them via the webpage.

Photos can also be uploaded there.

Anyone with a large number of slugs in their garden should visit www.slugwatch.co.uk to report their findings or ring the John Innes Centre on 01603 450000.

• Have you found something unusual in your garden or have the Spanish slugs affected your crops? • Email reporter donna-louise.bishop@archant.co.uk, ring 01603 693892 or follow @donnaloubishop on Twitter.