The research has been carried out by CABI, a not-for-profit agricultural research organisation, and the study has been peer reviewed by the Advisory Committee on Releases to the Environment. The team has spent several years trying to find potential candidates to control the spread of Japanese knotweed, looking for predators that feed only on knotweed and not on any of Britain's native plants. The psyllid has been tested on 87 non-target types of plant including those closely related to Japanese knotweed as well as ornamental plants and important crops, to determine whether it will feed on other plants. The findings suggest that only a few closely-related non-native knotweeds are potential hosts in Britain.

 

Dick Shaw, the lead researcher on the project, said: "This psyllid is a true knotweed specialist and our research shows that it could be a safe and effective control agent for one of our worst weeds. We are really pleased that the programme has reached the public consultation phase and look forward to hearing the outcome."

 

Japanese Knotweed was first introduced to the UK as an ornamental plant in the nineteenth century but it has since spread rapidly, damaging plant biodiversity as well as hard structures such as buildings, paving stones and flood defences. But getting rid of it using current methods i.e. weed killers and physical removal, is expensive - in 2003 the cost of national eradication was estimated at £1.56 billion. The researchers claim that biological control will be a cheaper and more environmentally friendly option for controlling the superweed.

 

There are two regulatory processes involved – the release of non-native bio-control agents is controlled under the Wildlife and Countryside Act 1981 and there are restrictions on the import and release of non-native plant pests under the Plant Health Order 2005. The public consultation document can be downloaded at http://www.defra.gov.uk/corporate/consult/japanese-knotweed/consultation-document.pdf and the closing date for the consultation is Monday 19^th October 2009.