A Year in the Valley

This is a smooth sow-thistle, which I have already posted, but I took a photo as it looked quite impressive and purple.  Then I noticed the leaf-miner tracks on the leaves.  Leaf miners are the larvae of tiny flies like the Liriomyza sonchi, which mines the leaves of sow-thistle species.  Leaf miner flies are very tiny – 2-3mm.  The larvae mine small white corridors between the upper and lower surfaces of the leaf and leave their droppings ‘frass’ as black dots in the leaves.