I saw these marks on the leaves of a common sow-thistle that’s growing out of a broken pot in the garden. I felt that I should have known what they were from but I just couldn’t remember. A little bit of research and the answer popped up – a leaf-miner. It is a generic term for the larvae of insects that live on the cells of a leaf, these can be beetle, flies, sawflies or moths. There are many different insects that it could be but it seems that many leaf-miners are very specific to the plants on which they feed. I would like to say I know what this one is, I think its Chromatomyia horticola, a fly, but I’m not 100% sure! If anyone can confirm that would be great 🙂
