What cuts neat half circles out of leaves

I've searched in the pests section and nothing's come up. Something is eating a neat half circle out of the edges of different plants in my garden--roses, rasps, lilac--whatever it is seems to like everything. I can't find an actual insect or caterpillar, just the evidence of noshing. Google hasn't been particularly forthcoming either. Hard to narrow enough. This is probably an everyday, common pest, but I don't know what it is or what to do about it. I'm on the lower Sunshine Coast.

 

Leafcutter bees, I think.

 

I think that might be what's doing it. In my search I had the impression they only went after roses, and the fact other plants are affected steered me off. I guess I'll just leave them to get on with it as they're important pollinators. Scallops are a nice effect too. Thanks.

 

I was told the bees are using the leaf cuttings to line/seperate their nests. If true - just think of it as providing baby blankets. ;)))