Japanese knotweed

Rivers in South Wales are being infested with Japanese knotweed. Surveyors have been carrying out a flood risk assessment on a major river in the area and were slowed up by the eight foot tall invasive plant that squashes any native species in its vicinity. The plant restricts the surveyor’s visibility and in turn their ability to measure, it can also grow through concrete and has been known to appear through the floor of peoples living rooms! Earlier this year the government granted approval for an insect from Japan to be released in order to control the quickly spreading weed. A spokesperson from the Environment Agency has said “The initial findings look promising”. The knotweed leaf on the right has a few chunks missing – I wonder if our friend the knotweed insect has just had his lunch, and I hope he has some mates because there is a lot of grub to get through!.

The other invasive weed that is prominent in September is Himalayan Balsam. It was introduced into Britain by the Victorians for its distinctive pink flower and sweet smell (pictured above – choking a river in Shropshire we surveyed). Little did they know how invasive it would be and it can now be seen on many rivers in England, Scotland and Wales and is only going to get worse if nothing is done. Do you think scientists could find an insect from the Himalayas to dine on our balsam?