I'm having an issue with my pumpkins and squash I haven't seen before. The pictures are below. It looks like what I've seen on the web as leaf miner damage, but the pictures I've seen have shown much larger tracks. These are tiny and also seem to be accompanied by yellow blotches and slow overall growth. Some other causes could be (1) I'm growing in a new area that was almost pure DG. I added lots of compost, and fertilized with fish/seaweed and compost tea, but maybe it's just going to take another year or two before the ground is really ready. (2) The area gets partial shade from some trees up above.

This is how it looks when it starts (pumpkin plant):

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Eventually, the whole leaf gets it, turns yellow and dies:

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I think this is the same problem on an acorn squash in the same area, though there's more yellow and fewer tracks:

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In my main garden about 50 yards away I don't get anything like this on my squash or anything else. Does anyone have any ideas? And if it is leaf miners, is there anything I can do about it? I've read that they're notoriously hard to control.

Thanks for any help you can give! Don