So what's the problem?
Japanese knotweed (Fallopia japonica) is one of the most damaging invasive weeds in the UK. It spreads extremely quickly, preventing native vegetation from growing, and is a problem to the construction industry as it is capable of exposing weaknesses in buildings, foundations, concrete and tarmac. Current control methods rely mainly on chemicals, and it has been estimated that the costs of control in the UK would be over £1.5 billion. CABI has been testing the potential for more sustainable, longer-term control using biological control methods.
What is this project doing?
CABI is carrying out the Government approved release of the specialist psyllid Aphalara itadori (Insecta: Hemiptera: Psylloidea) as a control agent for Japanese knotweed in the UK (see http://www.cabi.org/japaneseknotweedalliance/). After 7 years of research in Japan and in specialist quarantine facilities in the UK, it has been established that this tiny, sap-sucking psyllid is a knotweed specialist and can only complete its development on Japanese knotweed. The risk of damage to native plant species has been shown to be very low indeed.
The research programme and release are supported by various organisations, including Cornwall County Council, the Welsh Assembly Government, Defra, the Environment Agency, British Waterways, South West Regional Development Agency and Network Rail. The releases take place as a field trial at a number of sites in England and Wales. Part of the release is a monitoring plan, which aims to record the impact of the insect on the knotweed, but also to detect any potential adverse effects on native plants and invertebrates.