Dave Kilbey Photography

Autumnal colours arrive early

Posted by Dave Kilbey on Wednesday 22 September 2010 at 12:41pm

Horse Chestnut Miner Moth

This year, more than any other I remember, horse chestnut trees have taken a battering in Wiltshire and across the country.  Appearing to be undergoing a premature autumnal colour change the cause of the problem is actually the tiny caterpillar of the Horse Chestnut Miner Moth.


Leaf Miner caterpillars in a horse chestnut leaf (each is 7-8mm long)

 


Horse Chestnut tree showing extent of Leaf Miner damage



Unknown in this country 10 years ago, and not scientifically described until 1986, this Moth has radiated out from its believed source in Macedonia with alarming speed.  There seems to be no definitive explanation for the sudden range expansion.

Although drastic in appearance the damage caused by the leaf miner is generally aesthetic and temporary.  The principal symptoms of attack include browning, curling and premature shedding of leaves. 





Horse Chestnut Leaf Miner damage



In the majority of cases the tree survives relatively unscathed and it will leaf and grow normally in following seasons.  As a relatively new phenomenon the likely long term effect of the leaf miner on horse chestnut trees is not comprehensively understood.  Repeated attacks on individual trees will undoubtedly stunt growth rate and, although not a known direct vector of disease, it is thought the moth may make trees more susceptible to more serious problems such as bleeding canker via the damage caused to leaves.

Facts about the horse chestnut tree (Aesculus hippocastanum)

A non-native species to the British Isles the first horse chestnut trees were believed to have been introduced in the early 1600s from the Balkans.

The common name of horse chestnut is thought to derive from its superficial resemblance to trees of the chestnut family coupled with the fact that the nuts (conkers) were fed to horses, in days gone by, as an emetic and to cure coughs.

 

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