Hi, Stan: This would seem to be a pest of some sort, even one that eats and leaves. Try spraying very carefully with a very weak solution of dish soap and water, being very careful to cover both sides of all leaves. If this doesn't work, progress to a safe insecticide according to directions. It's not that we don't believe you when you say there's nothing there; it's just that it doesn't take very much to cause a lot of damage and then "disappear." Good luck!
Hi, Stan: This would seem to be a pest of some sort, even one that eats and leaves. Try spraying very carefully with a very weak solution of dish soap and water, being very careful to cover both sides of all leaves. If this doesn't work, progress to a safe insecticide according to directions. It's not that we don't believe you when you say there's nothing there; it's just that it doesn't take very much to cause a lot of damage and then "disappear." Good luck!