[Don_1 (OP)]

Japanese Knotweed was introduced into Britain in the 19th. C as an ornamental plant. Since then it has spread throughout the country, choking our native wild plants and depriving the wild life which depend on those plants. It is damaging buildings and roads. The problem was quite simply that this highly invasive plant came to Britain, but its natural predators did not.

If DEFRA & the Welsh Assembly give their approval, a Psyllid will be released into the wild to predate this plant. Research has, so far, found that this Psyllid lives exclusively on the sap of the Japanese Knotweed, so it poses no threat to native, or any other species.

Japanese Knotweed can grow at an amazing 1m per 3 weeks, so this Psyllid will have plenty to eat. But suppose this Psyllid were to develop a taste for something else. What might the consequences then be of having yet another non native species at large?

Is this the right road to follow? What are the chances of the Psyllid turning against us?

I would welcome the Psyllid if it did exactly as it say's on the tin, but I am worried that it could all go pear shaped.

What do you think?

[Bored chemist]

I just hope they have found a bug that can't cope with our cold winters or something so we can be sure that, if it goes wrong, it won't be forever.

[Madidus_Scientia]

I guess it depends how conclusive the research is, it may live exclusively on the knotweed if given the choice, but when knotweed becomes scarce what happens then? Are they able to digest other saps if they must or can they physically only survive on knotweed?

[Don_1 (OP)]

I guess it depends how conclusive the research is, it may live exclusively on the knotweed if given the choice, but when knotweed becomes scarce what happens then? Are they able to digest other saps if they must or can they physically only survive on knotweed?

That's what I am concerned about. However long it may take for this Psyllid to  munch through the entire UK Japanese Knotweed, suppose it runs out of its favoured food. Would it just die off, or would it adapt (as Japanese Knotweed becomes scarce) to feed on something else? Could it even find a food source it finds more tasty and start eating that?

I think tests on this Psyllid need to be absolutely conclusive, not a shadow of doubt, before we release another potential problem into the wild.

[BenV]

I think tests on this Psyllid need to be absolutely conclusive, not a shadow of doubt, before we release another potential problem into the wild.

Or we could gm them to be sterile...

[Don_1 (OP)]

Excellent idea Ben, I wonder if DEFRA have thought of this.

[Bored chemist]

I did see a newspaper article saying thet the bugs had been tested on "over a hundred" uk plants.
If you look here
http://www.thompson-morgan.com/seeds1/flower-seeds.html
you can see an alphabetical list of flowers for sale (other seed sellers are available)
"over a hundred" gets you to about the letter C on the alphabetical list.
I really hope they have looked at a lot more than that.

[Nizzle]

One option was not considered here.

What if the psyllid become favourite bird food?
The local birds would feast on the psyllid, and the Japanese knotweed will grow just as happily as before.

It's almost impossible to predict the effects on an ecosystem when introducing a new species...

[brsrvce12]

I think that the psyllid insects are a good idea, however i read that they dont have a natural predator in britain?

Do you think this means that an invasion from the bugs could be a possiblity too? The little insect feeds on the sap of the superweed but whos to say what sweet things it will begin to eat when the plant dies out?

I agree 100 plants is not really enough for a positive result