Japanese Knotweed

Baroness Sharples Excerpts

Thursday 24th June 2010 Lords Chamber

Asked By

[Baroness Sharples]

To ask Her Majesty’s Government what plans they have for preventing the spread of Japanese knotweed.

[The Parliamentary Under-Secretary of State, Department for Environment, Food and Rural Affairs (Lord Henley)]

A controlled release of the highly specialist psyllid—Aphalara itadori—is currently under way to help control Japanese knotweed. If successful, this should restrict its growth, slow its capacity to spread as vigorously and enhance the effectiveness of management effort. It would not eradicate it altogether.

[Baroness Sharples]

I thank my noble friend for that reply but is he aware that it is more than 20 years since I first asked about knotweed and nothing seems to have happened since then? Should psyllid be released and the genie is then out of the bottle, how can we ensure that it is safe? Is there not a problem for people trying to get mortgages? When it is proved that they have knotweed in their gardens or on their land they cannot get a mortgage.

[Lord Henley]

My Lords, we are all aware that my noble friend has been pursuing this matter for about 20 years. This is an experiment worth doing. We have put a great deal of research into the safety of the psyllid that is being introduced to ensure that it will not eat anything other than Japanese knotweed. So far, as far as we know, it does not. If we find any evidence that the psyllid moves off, we will quickly eradicate it to ensure that it does not cause the damage that uncontrolled releases of biological agents can cause.