Chestnut leaf miner moth blizzard

[Sylvia]

Garden's full of tiny striped flying critters - next door's Horse Chestnut leaves are almost totally brown - no other tree types/Sycamore /Oak /Rowan etc. affected - do these leaf miners only eat Horse Chestnuts leaves and will they eventually kill the Horse Chestnuts ie no green leaf surface left from July onwards ........are "sticky buds" impervious?

[sloth]

Garden's full of tiny striped flying critters - next door's Horse Chestnut leaves are almost totally brown - no other tree types/Sycamore /Oak /Rowan etc. affected - do these leaf miners only eat Horse Chestnuts leaves and will they eventually kill the Horse Chestnuts ie no green leaf surface left from July onwards ........are "sticky buds" impervious?

 

They will only go for Aesculus, I don't think it will kill them on its own. The latest research suggests that the leaves have long enough that the trees can photosynthesise before they are eaten, and are no more susceptible to bleeding canker as a result. Presumably that means they are no more prone to other ailments/attacks as well, which I find hard to believe. Surely if a tree is striped of leaves mid to late summer year after year it will have some effect on the trees ability to store energy?

[kieran connell]

is it a leaf miner, or Guignardia?

[sloth]

is it a leaf miner, or Guignardia?

 

Quite likely both. Tiny black and stripped flying critters sounds a lot like them though...

[Razzle]

HCLM (Horse Chestnut Leaf Miner) has been a serious problem for UK Chestnuts for a number of years now having spread rapidly from the SE in a short time. Only 4 years ago our company was warning clients in the Manchester/Cheshire area to be vigilant for the signature leaf margin feeding tunnels and to be grateful that their HCs only had bleeding canker. HCLM has now reached the borders and beyond.

Once HCLM has taken hold photosynthetic ability is hugely impaired.Early defoliation is likely and the tree becomes unsightly. The HC becomes stressed and is therefore more susceptible to other pathogens. In the case of the HC these pathogens are likely to be Bleeding Canker (Pseudomonas syringae) and Phytophthora.

Combined these afflictions are wiping out the UK HC population and yet all are treatable. Bleeding Canker and Phytopthora can be managed or suppressed depending on severity of symptoms while HCLM is easy to control with a foliar spray that is safe for bees,ladybirds and other beneficial insects.

Important and beautiful veteran HCs are being felled unnecessarily because institutions like the Forrestry Commision are, I am sorry to say, giving out poor advice.

[Paul Cleaver]

while HCLM is easy to control with a foliar spray that is safe for bees,ladybirds and other beneficial insects.

Important and beautiful veteran HCs are being felled unnecessarily because institutions like the Forrestry Commision are, I am sorry to say, giving out poor advice.

 

 

but how do you spray mature horse chesnuts?

[Stephen Blair]

With a back pack blower /sprayer I would think.

Leaf minor has been a problem round my way for nearly 10 years, this is the first year I have seen chestnuts and green leafs in ages.

They decline very very quickly once attacked.

Some pictures would be good of the said critters.

[Razzle]

Spray rigs for mature trees consist of engines, large pumps and a decent spray gun. Possible to get in the UK but not easily, had mine custom built after 10 years working as a Technician for Bartletts. Worked nationally treating Horse Chestnut Leaf Miner, Oak Processionary Moth at Kew and surrounding areas etc. Spray rigs and their services common in the US where Bartletts is based. Need more companies to offer the service here.

[Stephen Blair]

Sounds like your experiences are worthy of their own thread and pics.

I've never seen that done.

[MattyF]

How can you manage phytophera ?