Hi, My cannas were doing beautiful when all of a sudden, strips of leaves began to disappear. I watched the cannas for a while and saw many wasps or hornets around the cannas - they had long backward pointed legs. Eventually, they had the cannas completely stripped and assume they were building a nest with them. Anybody know what they are and if there is a good way to keep them away? Since I am trying to attract butterflies and hummingbirds, am hoping for a gentle solution. Thanks.