Knotweed under attack as biologists release killer beetles

A special beetle which devours Japanese Knotweed is to be released into the UK to combat the cost of clearing the invasive plant.

Japanese Knotweed is listed by the World Conservation Union as one of the world's worst invasive species.

It can grow vigorously at a rate of up to a metre a month, including through tarmac, concrete and drains and damaging roads and buildings. It causes over £150milion of damage in the UK every year.

Wildlife Minister Huw Irranca-Davies has given the go-ahead for the release of an insect, called a psyllid, to stop the spread of the non-native plant.

Using an insect - which is a predator of the plant in Japan - to act as a natural form of pest control, will be the first time that a solution like this has been used to help control the spread of a non-native invasive plant in Europe and, if successful, could reduce the costs to the building and engineering industries of clearing this invasive plant.

Irranca-Davies said, “This project is not only ground-breaking, it offers real hope that we can redress the balance. These tiny insects, which naturally prey on Japanese Knotweed, will help free local authorities and industry from the huge cost of treating and killing this devastating plant.”

Japanese Knotweed was introduced in Britain by botanists in the nineteenth century as an ornamental plant.