Umm..I haven't referred to my gardening books..yet..but yes, it will be some quite likely a result of insect damage. If it just shows on odd leaf..it is nothing serious to worry about and maybe resulted by just removing those few..don't drop them on ground, but take them away.
There is many different sort of aphids and some cause that same looking puckering on plants of different species..with those the 'damage' is usually just cosmetic, the leaf is still able carry on its 'duties' and one doesn't need to take any action. Often those insects do their damage earlier on the year when the leaves are still young and soft..the damage is not seen until later on when the leaves mature..then the insects have already moved on.
