Hi

I suspect it was greenfly just as the leaves opening and they had damaged them , have a look closely at the underneath of the leaves , they might have already gone by now .

Wont to any damage in the long run but will look unsightly for the rest of the summer.

These multiple "pin pricks" could be coming from an infestation of thrips or white fly to name a few. Check the underside of the leaves for that's where you will find the culprit. If you do, take a photo of it and send it in so the members can identify it for you and then tell you how to nip this problem in the bud. Welcome to GOY!