Well, I’ve been doing a lot of talking about the project but some of you probably just want to find out a bit more about the moth itself and see what all the fuss is about.
So what do they look like?
You’re much more likely to see the damage caused by the caterpillars of the moth than the winged beasty itself – the adults are a mere 5mm in size! However, come August, many Horse Chestnut Trees will appear to be undergoing a premature autumnal colour change.
In the large majority of cases this leaf damage is all the work of tiny leaf miner caterpillars – so called because they tunnel within the leaf eating the contents without particularly affecting the leaf’s epidermis.
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.
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.