DaisyI said:I suspect you are having an insect invasion. My first thought was aphids but then I noticed that beetle sitting on the post on the right side of your photo.
That beetle is a lightning bug, and it's a beneficial insect, so don't kill it. It's not hurting your cukes. However, from the picture, I also suspect an insect chewing on the edges while young, leaving scarred distorted leaves.
