Ian, when I see such damage I first think of Thrips or mites.
This time of year you might often see this damage and if it is no mite then mostly it's Privet Thrips.
On your leaves I see some silvery spots, which is typical.
I'm no expert and had to google a bit on the website of the research station in Holland to make myself clear about how to explain.
I see it here in my garden too and when damage is little, I pick some leaves off and throw them in the dust bin..
But when it's more damage some spraying with a stronger insecticide is the only way, I'm afraid.