This year, some pest ate the leaves on 6 columbines in our flower bed. This prevented the smaller plants from flowering, but the larger plants did flower--without the usual setting of leaves. Now, I've notice that some pest is eating the petunias in our flower boxes on the house. I don't know if they eat the flowers, but they are eating so much of the leaves and stems that the don't have a chance. I can't see pests on the leaves. Can extension help identify the problem?