Release of Psyllid Aphids
I have been prattling on about the Psyllid aphid release that has been suggested by CABI (a Government funded ‘not for profit’ organisation) and I will admit I have been very negative.
In my defence I would point out that my initial reaction on hearing of the
suggested bio control of Japanese Knotweed – was to contact CABI and in
particular Dr Richard Shaw in an effort to get myself up to speed on what was being suggested. Unfortunately I didn’t get a response to either phone calls or emails.
Instead of keeping quiet and awaiting release of information I put my thoughts in writing - which ended up on my Blog - which ended up being circulated around the internet ….and most of what I said was wrong.
I attended a recent seminar in Sheffield where Dr Shaw explained the reasoning behind the aphid release and the science behind the decisions that have been made….and it all made reasonable sense!!
Dr Shaw explained that the Psyllids (pronounced syllids) are very specific about what they will eat – and if they can’t find their specific food source they will die. SO in theory at least they shouldn’t go round eating any of our native plants. He went on to explain that the Psyllid won’t defoliate the plant (an assumption that I had made) IN FACT - the foliage will actually be more abundant in season two – making the application of chemical control MORE effective…also the plant will be weaker due to the psyllid predation - and thus should be easier to kill…
CABI are assuming that there will be a cycle of peaks and hollows in the
abundance of aphids – one season lots of aphids and a reduction in JK cover – next season less JK therefore less for the aphid to eat therefore it dies back – season three more JK because there are fewer aphids – season four more aphids due to mass of JK growth etc etc in a cyclical pattern (a little like Ragwort and the Cinnabar Moth to those of you familiar with that cycle).
Dr Shaw pointed out that he did not expect that the Aphid would be the one stop answer to all of our Japanese Knotweed problems. CABI also do not expect the Psyllid to kill the Knotweed plant on which it lives. What they are expecting is that a balance will be achieved between the predator and host which will reduce the invasive nature of the Japanese Knotweed and prevent the continued unchecked spread of the plant.
This must be supported by anybody either in the industry or anybody
wishing to see our native countryside protected.
I do still have some concerns about the use of one pest to get rid of another and the fact that the Psyllid has no natural enemies in the UK – however I now feel more inclined to accept the fact that this release is going to happen.
Our approach at Japanese Knotweed Solutions will be to work with the
Government experts - and try to ensure that we continue to offer our clients the most up to date practical advice on controlling and managing Non Native Species.
And in future I shall learn to keep my mouth shut until I am fully aware of all the issues.
Mike C
March 10th, 2010 at 12:05 pm
Dear Mike, How reassuring to find someone who is prepared to admit they may have spoken out of turn. Incidentally I think it is better to speak (and be prepared to acknowledge an error) than not to speak at all!
My daughter Jennifer is currently doing an MA in Science Journalism at City University and is basing her final TV documentary on JK. I’m sure she would be grateful for any feedback you might be able to supply. Her e-mail address is jennifer_r_a_green@live.com if you feel you can help? (One of my brothers works for CABi - small world!)
Kind regards
Deborah Green
March 14th, 2010 at 3:47 pm
Hi Deborah, with my big mouth I need the ability to admit that I have been wrong! I too believe in talking about issues and being prepared to ask questions and maybe occasionally make a fool of yourself. I have been talking and blogging about how the governing bodies have tackled the Psyllid release and how it has/has not been advertised (im yet to meet anyone who knew about the ‘public consultation’..!) trying to raise awareness of the issues which i feel are important.
I would be happy to help Jennifer if i can - perhaps she can e-mail me with any areas on which she would like information - or she would be welcome to attend our semimar in Manchester on 25th March if she is available??
Mike C
March 23rd, 2010 at 12:59 pm
Hey Mike,
I think it was very good of you to apologise for speaking out of turn. However your post would have spoken for many people who think the same and with little explanation for a plan regarding the fact that the Psyllid has no natural enemies in the UK many would most probably have agreed.
I enjoyed reading your posts all the same!
Thanks