horse chestnut leaf miner moth (1 Viewer)

[mjop]

Some readers might be interested in taking part in a survey of the horse chestnut leaf miner and its parasitoids that I'm running. All the instructions are at the Conker Tree Science website at www.ourweboflife.org.uk

The moth (as you might know) is a pretty little moth that is devastating horse chestnut trees. Although it doesn't kill them, the evidence suggests that they produce smaller conkers and become more susceptible to lethal diseases like bleeding canker.

You can enter sites where you have found the damage caused by the leaf miner, and the amount of damage caused, at the Conker Tree Science website (www.ourweboflife.org.uk).

One thing we would like to know is whether the rate of parasitism of the caterpillar is highest where the moth has been longest, and how quickly the rates of parasitism reach their peak. This is genuine scientific research that you can help with. All you need to do is locate an infected horse chestnut tree, pick one leaflet from a leaf and put it in a plastic bag THIS WEEK. Then two weeks later identify what has come out (there's an id guide on our website) and enter your results on our website.

Thanks for your interest in Conker Tree Science.

Michael Pocock

 

[karpman]

Some readers might be interested in taking part in a survey of the horse chestnut leaf miner and its parasitoids that I'm running. All the instructions are at the Conker Tree Science website at www.ourweboflife.org.uk

The moth (as you might know) is a pretty little moth that is devastating horse chestnut trees. Although it doesn't kill them, the evidence suggests that they produce smaller conkers and become more susceptible to lethal diseases like bleeding canker.

You can enter sites where you have found the damage caused by the leaf miner, and the amount of damage caused, at the Conker Tree Science website (www.ourweboflife.org.uk).

One thing we would like to know is whether the rate of parasitism of the caterpillar is highest where the moth has been longest, and how quickly the rates of parasitism reach their peak. This is genuine scientific research that you can help with. All you need to do is locate an infected horse chestnut tree, pick one leaflet from a leaf and put it in a plastic bag THIS WEEK. Then two weeks later identify what has come out (there's an id guide on our website) and enter your results on our website.

Thanks for your interest in Conker Tree Science.

Michael Pocock

Many thanks will be taking part my local patch has some conker tree's that look as if there dead not a green leaf in sight!

karpman:t:

 

[Surreybirder]

Yet another example of someone irresponsibly releasing alien species into the wild - in Austria if I remember correctly.
I think they occur throught Surrey now in countless numbers.
Ken

 

[antshrike69]

Absolutely. Although of course Horse Chestnut itself is also introduced in the UK.

 

[Brian Stone]

Widespread in Hunts as well of course. I first trapped it in my garden in 2006.

 

[harry eales]

I signed up some time ago, but I've yet to find any evidence of this micro in Northumberland, Durham or North Yorkshire this year. Having said that, I now know where to collect masses of Conkers. lol.

Harry

 

[honeym]

Yet another example of someone irresponsibly releasing alien species into the wild - in Austria if I remember correctly.
I think they occur throught Surrey now in countless numbers.

Hi Ken

I am curious where you got this information.

Martin

 

[honeym]

Hi Ken

There's no need to respond as I think I've found the site where this is mentioned (http://www.forestpests.org/leafminers/miners/camerariaohridel.html). It's just odd that I've not read or heard about this particular story before.

I still think much of what is said about this species is pure speculation. What has always surprised me is that, if it was introduced from some country or other, why we didn't already know about it from that country. There are also other stories - equally without any supporting evidence.

I don't really think that the spread would have been influenced much by the accidental 'escape' (so possibly not a deliberate release) as it was already on the move by that stage and, without natural enemies (i.e. parasites) to control it, it spread dramatically - ably assisted by man (road and rail transport), albeit unwittingly.

I have heard that in some areas on the continent, the population levels stabalise after around 10 years, so it will be interesting to see what happens here.

We still have much to learn about it.

The main problem for the trees is that they are under a three-pronged attack - the leaf miner, the fungus and a bleeding bark disease. The latter two are a far more serious threat in my opinion.

Martin

 

[Surreybirder]

Hi Ken

There's no need to respond as I think I've found the site where this is mentioned (http://www.forestpests.org/leafminers/miners/camerariaohridel.html). It's just odd that I've not read or heard about this particular story before.

I still think much of what is said about this species is pure speculation. What has always surprised me is that, if it was introduced from some country or other, why we didn't already know about it from that country. There are also other stories - equally without any supporting evidence.

I don't really think that the spread would have been influenced much by the accidental 'escape' (so possibly not a deliberate release) as it was already on the move by that stage and, without natural enemies (i.e. parasites) to control it, it spread dramatically - ably assisted by man (road and rail transport), albeit unwittingly.

I have heard that in some areas on the continent, the population levels stabalise after around 10 years, so it will be interesting to see what happens here.

We still have much to learn about it.

Presumably you are familiar with http://www.ulb.ac.be/sciences/lubies/offprint/2004GilbertCo.pdf

The main problem for the trees is that they are under a three-pronged attack - the leaf miner, the fungus and a bleeding bark disease. The latter two are a far more serious threat in my opinion.

Martin

Interesting theory, Martin. I've no idea where I read the stuff about the deliberate release but I'm quite prepared to believe it's fiction.
Perhaps a lot of these scare stories are made up. But I'm old enough to remember Dutch elm disease (obviously not introduced by a mad Austrian scientist).
Off topic, I know, but I have been concerned at an invasion of Marsh frogs around Newchapel, where I live. These were introduced by a former neighbour and there were thousands of tadpoles in the spring. But I've just heard from the Surrey Amphibian and Reptile Group that they are probably harmless to other amphibians... so you never can tell. (They aren't half noisy at night!!)
Ken

 

[Wandered Scot]

Hi Martin and Ken,

Being in the middle of the source, and in a certain Government institute that is studying this, I can confirm the moth was not known because it was happily living in a backwater, and so far as we can tell in equilibrium, but the curiosity of a less than careful collector upset that, who from people here that knew him and this case better than I do, can and do confirm the case of deliberate release here in Austria. Whether it would have spread without his help, will now never be known.

Cheers

Jim

 

[Surreybirder]

Ah... now I remember where I heard about the deliberate release!! The Scot himself.
Ken

 

[Mary]

Many thanks for this link, I'd been wondering why our horse chestnuts were in such a state. The first moths from leaves I collected have started hatching out. They are so tiny you wonder how their grubs can cause such devestation! Yet in the photo on the website they are beautiful moths!