Insect could halt the spread of Japanese Knotweed
Defra Ministers are seeking views on proposals to release the non-native psyllid Aphalara itadori (a tiny insect) to help control Japanese knotweed (Fallopia japonica). This plant has spread across Britain since being introduced as an ornamental plant in the early nineteenth century and costs the country millions of pounds in repairs to buildings, roads and railway lines.
The government is considering an application for a licence to release the psyllid to attack the plant and lessen its vigour, thus reducing the use of chemicals and the costs of control including weed killers and physical removal; the cost of eradication nationally using conventional methods was estimated at £1.56 billion in 2003.
If a licence is issued, it is expected that the psyllid would be released and monitored at a small number of sites initially, followed by wider release in England and Wales.
Five years of research by scientists at CABI has shown that Aphalara itadori is the best candidate to help control Japanese knotweed in Britain. 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. The findings suggest that only a few closely-related non-native knotweeds are potential hosts in Britain. The research has been peer-reviewed by independent scientists and the risk assessment for the study assessed by the Advisory Committee on Releases to the Environment.
The deadline for consultation responses is 19 October 2009.
Further information
Page last modified: 27 July 2009
Page published: 23 July 2009