Marilyn, that might be a good topic for discussion in pests/diseases section:
http://garden.org/forums/view/...
I'd be curious to hear what others have to say too since I'm unaware of any flies that chew on plants and/but I like to know what's going on even if I don't interfere. It looks like caterpillar damage to me, they're very good at hiding/camouflage, but if it's something else, I'd also love to know.
That kind of damage doesn't bother me at all, but if I only had one or a few plants, that I often looked at more closely than standing next to the bed they're in in the ground, I might look for the critters responsible and be more proactive about creatively relocating them. In any case, best luck!
