Anything is welcome to munch on my Canna leaves as long as I get some blooms. But the rollers seem determined to eat all of the blooms. That's an unacceptably greedy situation. I'll forego Cannas altogether if that's all that is ever going to happen. But if the occasional harsh winter slows them down enough to get some blooms some years, that would be an OK compromise with me. My jury's still out, although the drought the past couple summers left my Canna patch much smaller, a few weak leaves just poking up. If it happens again this summer I don't think there will be any of those left, just a few in a pot that the folks redoing the city sidewalk pots gave me because I happened to be driving by & stopped to ask for some.