I searched the web a little bit today to find information on leaf rollers since I have had such a problem with them this year. I have found empty cocoons on leaves that I didn't unroll right away so I knew that those nasty little green worns were coming from some kind of Moth or Butterfly. I was hoping they were coming from a butterfly . . . They don't. . . They don't even come from a pretty moth. Its an ugly grayish brown moth.
I have always handled these by either removing the infested leaf but I had so many this year that my canna lilies were looking really sparse. My second technique is to start from the bottom, run my fingernail through the stitching and unrolling the leaf. I clean out the leaf and feed the worm to my fish. Unfortunately the leaf is still badly scarred on at least one side after this. I've read about another method in which insecticide soap is put into the end of the rolled up leaf to kill the worm but I suspect that this method will kill the leaf as well.
Since moths are attracted to light the trick might be just planting them someplace where there won't be a lot of light at night.
