It’s sad to see so many horse chestnut (conker) trees affected by the leaf miner moth caterpillar (Cameraria ohridella) – it’s what causes the brown discolouration of the leaves that makes it look like autumn when it’s still summer. These tiny caterpillars burrow within the leaves, damaging them. Most of the horse chestnuts I worked around today were affected; the pest is now widespread in England since it first appeared in London in 2002.
Many horse chestnuts have other diseases to contend with and the leaf miner’s damage to the leaves reduces their ability to photosynthesise, affecting how much food they can produce.
So here’s another good reason to encourage birds and improve their habitat – it seems that some of them like to snack on the leaf miner.
- Find out more about the leaf miner and other problems affecting the horse chestnut here
- A blog post on the horse chestnut leaf miner by Phil Scott, Forestry Adviser to the National Trust
- If you’re a woodland owner, please take the British Woodlands Survey 2015