Talkback: Leaf miner fly

I hope you can help me? I have a weeping Willow tree in our garden. Our weeping willow has developed some sort of problem which I have to say I have no idea what it is. Some of the leafs on the willow are turning yellow and are presenting some brown spots. There are also some brown marks to the the stems to the leaves. Quite alot of leaves have fallen from the tree. We are also getting some dead wood in the tree right thing but I have removed the branch which had the fungus on it

Is there a treatment for leaf miner fly? If so, what is it?

A systemic insecticide will deal with it, but you really have to spray before they appear. They are harmless, just disfiguring.

I had to throw nearly all my lettuces last year, the leaf-miner making them totally inedible.