Turning back a Japanese Invader.

Japanese Knotweed is so dangerous there is legislation banning its cultivation and movement. Even a tiny fragment can regenerate, and it can grow through concrete and tarmac. Introduced during the Victorian era, it has now colonized almost all of Britain. And once you have Japanese Knotweed it is almost impossible to shift.

Enter the unlikely hero and saviour, the Aphalara Itadori, a small sap sucking insect from Japan. Scientists from (CAPRI) the Centre for Agricultural Bioscience International, are thinking of releasing it into the British countryside. The aim is to introduce the Knotweed’s natural predator to help bring it under control.

The scientists involved at CAPRI have assessed the impact of 186 species of insects and 40 fungi for their potential to curb the knotweed. The result was that the Aphalara Itadori, and one fungus, the Mycosphaerella leafspot fungus, would do the job. They also tested the Aphalara Itadori on 79 other plants to make sure they were not a threat to the local plant life.

They are now waiting for a decision by the Department of Environment and Rural Affairs to allow them to release the insect under license. But this policy does not please everyone and there are dangers involved.

The grey squirrel was introduced into Britain in the late 19th century, since then it has almost driven Britain’s natural squirrel, the red squirrel, into extinction. In Australia the cane toad was introduced in the hope that it would protect the crops from the damage done to them by the cane grub. However, the cane toad was to do untold damage because it either ate the natural wildlife, or poisoned any animal which tried to eat it.

Around the world insects have been released to control invading plants, and they have had some successes. As far as Japanese Knotweed is concerned doing nothing is not an option.