I thought it was mite damage originally but there are small holes happening also and it looks different than previous damage of that kind that Ive seen.
It might be that your plants are losing water, and the water droplets are forming on the edges of the leaves in the early morning before lights on...and when your lights turn on, they are burning the holes in your leaves.
Are your humidity levels above 80 percent?... and your temps above 84?... if so, that may be your issue.
It's a possibility... If all else fails, check them before lights go on and see if it looks like you have morning dew on your leaves.
INSECT FOR SURE !!! i just had the same damage, it was 1 or 2 plants per 15 lady section only a couple of leaves. All i found was a lil green mini grasshopper. The damage subsided on its own and im 5 weeks into flowering no sign of the buggerz. Good luck 2u. If your not flowering yet, id go with spinosad like outwest said.