Perfectly round holes
(Atlanta, Georgia, USA)
Something is making perfectly round holes in my Wisteria leaves, my crape myrtle leaves and my pansy petals. I've seen small brown moths around the areas and have sprayed Sevin, which hasn't done any good. I talked with a master gardener and she said she didn't think it was the moths. I was going to put moth balls around the plants, but after some research, I'm not sure that would be a good idea, plus I don't know for sure it's moths.
I think it is the moths - keep in mind that they produce a caterpillar, which chews on the leaves and buds of many plants. I would take some of the leaves that are showing the holes, and put them in a jar to see if you get them hatching out to determine for sure if this is the culprit.
Many moths go in cycles; their population booms and then some predator will come along and clean them up. Unfortunately, what happens when you spray any kind of chemical (such as Sevin), it kills everything. I'm a big believer in letting nature take its course, and leave it alone to do its thing.
It won't hurt the plants to have a few holes in the leaves; they are able to withstand considerable damage and still support the growth of the plant. The holes that exist now won't heal over, so you're stuck with them for this year.
Generally (tent caterpillars and spruce budworm being the exceptions) it won't do any lasting damage, especially in the case of deciduous plants that are going to lose their leaves soon anyway.
My recommendation is to rake the leaves (or even prune them off) and burn them or compost them in a really hot compost pile. This will eliminate the larvae, and prevent a reinfestation next season.