Belfast Telegraph

Worm invasion costing Northern Ireland £34m a year

Invader: New Zealand flatworm
Invader: New Zealand flatworm
Allan Preston

By Allan Preston

An invasion of killer worms cost Northern Ireland £34m last year, with the deadly species from Down Under ruining our soil and preying on native earthworms.

The predatory New Zealand flatworm has been named in a list of invasive species costing the UK more than £2bn last year.

Covered in sticky mucus, the flat-shaped invader has seriously decreased the local population of earthworms who have a crucial role to play in maintaining soil fertility.

The flatworms wrap their body around their prey, liquefy them with digestive juices and ingest that through a tube on their underside.

It's believed the killer species was first introduced to Northern Ireland in 1963 as a result of contamination of plant potting soil imported from New Zealand.

Present in all six counties, the greatest concentration is thought to be in built-up urban areas around Belfast.

Colette O'Flynn, an invasive species officer with Biodiversity Ireland, said the flatworm's "voracious appetite for earthworms" was ruining soil quality here.

She said a longer history of importing potted plants from Great Britain meant the problem was far more widespread in Northern Ireland, but the true extent may also be under-reported in the Republic.

"They are a predator in Ireland, putting pressure on our eco-system and upsetting the balance of life," she explained.

"Earthworms eat organic matter like dead leaves, breaking it down and putting rich nutrients into the soil. They also burrow and mix the soil, bringing more air and health into fields."

Unable to burrow underground like their earthworm victims, flatworms instead slither near the soil surface and under rocks. Ms O'Flynn said prevention was the best way to protect local gardens. "If you're bringing in potted plants or soil, have some inspection done to make sure they're not infected with New Zealand flatworm or their eggs, which are small black and shiny like a broken-up blackberry," she advised.

Laying down traps, she continued, was the best way to drive the invaders out.

"They can't burrow - you tend to find them hiding away from the sun under pots of plants and stones."

She advised laying out a sheet of black plastic with a stone on top to attract the flatworms.

"It really is a very local effort, I don't really know of any effective chemical solution."

Colours of the flatworm can vary making it difficult for members of the public to identify, but in general specimens are grey or brown with both ends pointed and covered in sticky mucus.

Wildlife and Countryside Link, a coalition of 48 charities that yesterday issued a warning about invasive species and their cost to the economy, also called on the government to take action on other intruders, including Japanese Knotweed, grey squirrels and mink.

Belfast Telegraph


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