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New approach to tackling Japanese knotweed

A tiny insect has been approved for use in the battle against invasive Japanese knotweed, but not everyone is convinced it’s safe. Wildlife minister Huw Irranca-Davies gave the go ahead for the release of the insect, called a psyllid, which is claimed to be a natural predator of the plant in Japan.

Japanese knotweed, introduced to Britain by botanists in the 19th century as an ornamental plant, has become a menace. It’s listed by the World Conservation Union as one of the planet’s 100 worst invasive species. The weed is vigorous, growing at up to a metre a month. It destroys habitats for native species and can break through Tarmac and concrete.

Huw said Japanese knotweed causes over £150million of damage in the UK every year: “But these tiny insects, which naturally prey on Japanese knotweed, will help free local authorities from the huge cost of treating and killing this devastating plant,” he explained.


But could the cure cause an even bigger problem?

Fears are growing about the consequences of releasing the psyllid if it does not behave in the wild as scientists expect. Mike Clough, managing director of Japanese Knotweed Solutions, said “real concerns” remained about the aphid – claimed to be the first time that a non-native insect species has been released in the UK outdoor environment. “Like Japanese knotweed, the aphid is an alien species with no known predators in the UK,” said Mike. “The public needs reassurance that there are stringent controls in place to ensure that we do not have a bigger problem on our hands if the aphid acts differently than expected.”