Invasive ‘killer slug’ found outside Norwich

Spanish slugs. Pic by Dr Ian Bedford

Spanish slugs. Pic by Dr Ian Bedford


A voracious “killer slug” found in a back garden outside Norwich could be the first UK invader from a species which has attacked crops and devoured dead mammals in mainland Europe.

The Spanish slug, which earned its “killer” nickname from its aggressive and cannibalistic tendencies, has been identified in this country for the first time after being spotted by scientist Dr Ian Bedford, head of entomology at the John Innes Centre (JIC) in Colney.

Dr Bedford’s role at the internationally-renowned plant science and microbiology centre meant he was alert to the appearance of potential crop pests, and resolved to find out what species had destroyed the garden vegetables at his Cringleford home.

His suspicions were confirmed by Aberdeen University, where experts identified the species as “Arion vulgaris”.

Now researchers from the John Innes Centre and other UK universities are preparing a plan to investigate and tackle the problem.

Dr Bedford suspected the large brown slugs in his garden were invaders due to their vast numbers and their aggressive behaviour.

He said: “There were very strange things happening, like seeing a dead mouse which the cat had killed being eaten by this particular type of slug.

“It was something I had not seen before, and particularly in such large numbers. You could easily find 100 on the lawn. I grow vegetables and when I saw the carrots coming through the whole lot would be gone by morning, like a lawn-mower had gone through and wiped them out.”

Dr Bedford said it was a “great concern” that the species had arrived in Norfolk.

“East Anglia does seem to be an open door to invasive species like this,” he said. “Whether that is because we import a lot of products, or that we have a lot of ports, or our close proximity to Europe, I don’t know.

“We have had a lot of reports from growers around the county of horrendous problems with slugs this year, with some rape crops being re-own twice.

“They’ve caused damage to a vast range of plants that you wouldn’t expect them to attack, like the foliage on potato crops, onion tops and chives, broad beans and runner beans.

“We suspect a lot of those things that were reported are linked to Arion vulgaris. So obviously we have got to do something.”

Dr Bedford’s discovery has launched a research project which also includes Aberdeen and Newcastle universities, and could include The Genome Analysis Centre (TGAC) at Colney,

“We (the JIC) have got experience of looking at organisms in laboratories but we can also use TGAC to try and identify the types of parasites these slugs carry, and to find out if these species has been breeding with our indigenous slugs,” he said. “Because it is an unknown, we need to do this very carefully and very quickly.

“We need to be ahead of the game and the first step to try and control this pest is to understand is as much as possible. We need to find its Achilles Heel.”

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