Often, before it gets to the stage Anne showed, you see a perfect row of holes in the leaves. The caterpillar bores in when the leaf is still rolled tight and as it unfurls you see this lines of holes.
I had a terrible problem with leaf rollers on the native Canna florida but once I got rid of the plants and waited about 3 years, I have never had a problem since. I have Tropicanna, Tropicanna Gold, Patens, a couple of miniature NOIDS and C. Warscewicii.
