Today I watched a horse chestnut leaf miner moth, Cameraria ohridella, laying her eggs on the fresh young leaves of a horse chestnut tree. Here’s a short film that I captured.
The tiny larvae will hatch in about three weeks and start to feed on the tree’s resources. First the sap by tapping the veins, then by eating the leaf tissue. This is when the brown spots appear as the larvae ‘mine’ the leaves. By mid summer, trees infected by heavy populations of the leaf miner larvae may appear Autumnal; their leaves brown, blotched and tatty.
The Sylva Foundation is looking for volunteers again this year to help spot the presence or absence of leaf miner damage on horse chestnut trees across Europe. Why not get involved? See www.TreeWatch.com