Diseased horse chestnuts

[m1.carson]

Hi,

Last year there was a post concerning diseased H/chestnuts, but can't find it,

There's a row of these not far from where we live, all in this Autumn condition, I think the disease was to do with sap, anyway does it need reporting, I think they belong to the council.



Max.

[mrs fish]

It is a little moth called the Leaf Miner that causes it

UKMoths - Horse Chestnut Leaf-miner Cameraria ohridella

Forest Research - Horse chestnut leaf miner - Cameraria ohridella

The Horse Chestnuts around here have recovered well from how they were the last two or three Summers

I did see one the other day though that is suffering

[m1.carson]

Thanks for the reply Mrs Fish,

I'm not sure that a moth can cause nearly all the leaves of approx. six trees to turn Autumn brown, I did read the link and it said brown blotches, not the majority of the leaf.

Thanks,
Max.

[IanS]

It is a moth (well their grub anyway), millions of them. Seen a lot of trees further south suffering from it again this year. Hopefully they will keep bouncing back each spring and get their growth in early before these pests attack again.

[Dogghound]

Another option to the moth is it could be the result of Guignardia leaf blotch, often the moths are mistaken for this fungal infection which mainly affects the tips and edges of the leaves. The name of the fungus is Guignardia aesculi.

[djackso]

I saw a similar tree, I tore the blisters and I found no moth. In this case I think it was fungal - thanks for the possible ID Dogghound.

[aeshna5]

The leaf miner is pretty prevalent around me + this week have seen mini swarms of the moth flying below the trees, even in the rain.

However more serious is a canker which can be fatal to the trees + is assciated with the sap run.

[m1.carson]

Hi mrs fish and all,

I have to admit you must be right about the leaf miner, took a close up this AM.






What a ruin it's made in such a short time.

Thanks Max.

After looking at the map we're almost smack in the middle of the infestation.

[mrs fish]

The trees around our local school were leafless due to it two to three years ago but look nice and healthy now

[Wild-Woman]

I've seen the Cameraria ohridella moth under a lens. They're really tiny but very attractive looking with stripey wings, even though their larvae are responsible for loads of leaf damage to the leaves of horse chestnuts.

It seems that the trees in the south will probably suffer most as they will probably be able to have more generations.

Advice from the FC is to clear leaves in the autumn and compost under 4cm of soil so that new moths won't be able to emerge.

Most of the Horse Chestnuts here have some degree of damage. Some look in a very sorry state indeed. I think we'll have to wait for some parasitoid of the moth to catch up with it before it gets under some control.

[seanh]

Round these parts (Kingston-upon-thames) about 99% of all horse chestnuts are in a very bad way suffering from both canker and leaf miner. I've found only 2 or 3 trees this year that are untouched and these were all the red non seeding variety (one tree was grafted - the upper portion was healthy but suckers from the base were infested with leaf miner).

This situation has been getting steadily worse in the last 3 years and looks prety bleak for their survival.

[Adam Cheeseman]

Ironically, I sent out a press release from work yesterday on this subject, having received several comments from the public that the HCs were turning brown for autumn early whilst all the other trees were still green.

Cheers,

Adam

[derelict]

Originally Posted by Wild-Woman

I've seen the Cameraria ohridella moth ...
I think we'll have to wait for some parasitoid of the moth to catch up with it before it gets under some control.

The HC trees in Richmond Park (not far from KoT!) have been suffering since the summer - they started at out as the first lush greenery in the park but by June a number were getting blotchy leaves - I photo'd some at the end of June - initially I thought they had been parched by a hot dry spell coming at the wrong time but obviously I've since looked at the leaves. Curiously, unlike the oak trees which have suffered a similar double-whammy combination of insect and fungal attack the HC's are bearing fruit, though the nuts do seem to be on the small side. Sadly parasitoids are not the answer - what is really needed is a good hard winter to reduce the overwintering pest populations.

[seanh]

Seems that the trees were suffering badly before the moth infestation according to this report:

Bleeding Canker of Horse Chestnut

Also not surprising the problems are particularly noticeable around here as the moth infestation first appeared in wimbledon around 2001:

Horse chestnut leaf miner - Cameraria ohridella

[derelict]

From Putney Heath - halfway between Wimbledon & Richmond - earlier this week

I don't know whether this is a bizarre consequence of the infestations ... this tree has produced fruit - prematurely nabbed by the resident grey squirrels in absence of any local acorn crop (see "Acorn Crop Failure 2008" thread)





(detail of bottom right)

[Adam Cheeseman]

Originally Posted by seanh

Seems that the trees were suffering badly before the moth infestation according to this report:

Bleeding Canker of Horse Chestnut

Also not surprising the problems are particularly noticeable around here as the moth infestation first appeared in wimbledon around 2001:

Horse chestnut leaf miner - Cameraria ohridella

In 2005 they were suffering from the moth, the canker, the rust, and the drought. It's a wonder they survived that onslaught.

Cheers,

Adam