May 27th, 2011 by Dave Kilbey
Horse chestnut trees are looking beautiful right now – and many were festooned with flowers at the beginning of May. I’d almost forgotten what they should look like.
However, all is not well. Upon closer inspection several trees close to my home had their leaves dotted with adult horse chestnut leaf miner moths – the first live ones I’ve seen. I must admit to being somewhat shocked by the sheer number of moths present (I counted 28 on one leaf!) However, one interesting observation that confirms what Michael Pocock has said to me before, (Michael is the principal horse chestnut leaf miner moth biologist on the project), is that on several trees in a well-kept garden where the leaf litter had obviously been cleared away, no moths were present at all as far as I could see.
Could this be a solution and a realistic way of reducing the damage to our trees? Cleaning up and burning the leaf litter every autumn? Given that a large proportion of the larvae will overwinter in the leaf litter itself it will certainly help reduce the number of adult moths. Whether this will have a significant effect on the damage done to trees is, as far as I know, un-tested as of yet. And I suppose another issue is whether burning leaf litter is actually an environmentally sound thing to do from a CO2 perspective?