Leaf Miners

[armybloke]

A large number of Holm Oak are exhibiting this leaf minor and from a distance the trees look like they are deciduous!

[armybloke]

Betula utilis var. jacquemontii having serious problems. It has been hammered by over pruning but this is being attacked. A Betula pendula is growing just a few metres away unscathed by it all!

[RDB logs]

A large number of Holm Oak are exhibiting this leaf minor and from a distance the trees look like they are deciduous!

 

Hi army bloke, have you seen this in previous years? Do you know if holm oak bounce back well? I have one that's got it real bad. Just wondering on it's long term future?

 

We could do with a proper hard winter.

 

Cheers

[David Humphries]

Poplar leaf mining

 

possibly by the larva of the poplar bent wing moth - Phyllocnistis unipunctella

 

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[David Humphries]

leaf miner of London plane - Phyllonorycter platani

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[David Humphries]

haven't seen the adult moth yet but understand that it's fairly similar to Cameraria but a bigger.

 

Phyllonorycter image (top) courtesy of UKmoths

Cameraria (below)

 

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[benedmonds]

Poplar leaf mining

 

possibly by the larva of the poplar bent wing moth - Phyllocnistis unipunctella

 

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Do you think this the likely cause of this? 20 or so big pops pretty defoliated..

[David Humphries]

possibility Ben

 

this is what UKmoths have for it.......

 

Phyllocnistis unipunctella - UKMoths

 

 

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[Razzle]

As far as the Horse Chestnut is concerned Dexta, you SHOULD be worried.Year on year HCLM is becoming more severe and more widespread. Yes trees can compensate for foliar damage of one sort or other but not indefinitely. Once the tipping point has been reached, overall vitality drops significantly leaving the tree more susceptible to Psuedomonas bleeding canker and Phytophthora, amongst other pests and diseases.

A significant amount of research has been carried out over a no. of years by leading industry experts including Dr Glynn Percival and the scientific papers to back up the research have been available for years.

Unfortunately the Forestry Commission are doing the Horse Chestnut no favours when it continues to give misleading advice stating "not to worry ,the tree will reflush next year"!! Well that's great but as with all foliar pests and diseases,or at least the effects caused on the leaves of deciduous trees, yes, of course the tree will come into leaf the following year, but each year the symptoms will generally become worse until it succumbs to another pathogen or chainsaw.

The bottom line is the Horse Chestnut is finished as an adopted native species in the UK without a more proactive approach to tackling pests and disease from institutions like the Forestry Commission and Forest Research who are great at telling us all about the symptoms and spread of a particular problem but appear unable to endorse other bodies research with regard to treatment because they haven't had the funding to produce the science themselves.

Sounds hard to believe? Well I was crestfallen when I met a particular Forest Research scientist a few years ago (who I shall leave anonymous) who's idea for a management strategy for pests and disease in trees was either to do nothing other than to monitor it, or cut it down and burn it.

Proactive management strategies have been proven and available for a host of prominent UK pests and diseases for along time ie Oak Processionary Moth, Phytophthora sp. HCLM to name a few. Hopefully with the publicity around Ash dieback (Chalara fraxinia) there will be more pressure to come up with treatments, they exist already for Ash Dieback its just a matter of getting one registered for UK use.

Its time to start moving away from our chainsaw culture and start adopting,or at least acknowledging other methods and practices.

Sorry for the rant but we still seem to be so far behind the US when it comes to tree health care.

[David Humphries]

Evergreen Holm oak that has dropped 90% of its foliage probably in part to a number of constant years with the associated leaf miner (Ectoedemia heringella)

 

Budding up nicely and soon to wearing its new suit.

 

 

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Edited May 9, 2016 by David Humphries