Are You Mine?

I found a load of birch leaves with some very obvious feeding damage. I reckon this has to be a sawfly, and the damage is not too dissimilar to the Zig-zag Sawfly on Elm - except being within the leaf rather than from the edge. It's not really a mine as such. You'd think that this would be straightforward to identify the culprit, but so far I have no idea. No larvae on any of these though, so it's one I will have to make a point of looking out for a bit earlier in the year next year if I remember ....

One that certainly is a mine was this gallery leading to a blotch typical of a dipteran miner, this one on bramble ....

This fits Agromyza idaeiana. The above phone snap was taken when I found it, what I hadn't noticed until now was that the photo I took at home of the larva in the mine, just over 24hrs later, shows that the blotch had developed substantially in that time. In the photo above, use the obvious dark spot just to the left of the the blotch as a reference; in the photo below you can see that it is a load of frass which is now much lower down the leaf than the top of the blotch which is now doubled in size.