Acephate has been the most effective liquid "systemic" control of the lesser canna leaf roller I have found and used for many years. I have tried many other products. Once the chemical dries on the foliage, it is absorbed and distributed to the growing plant. I prefer to spray late in the day when bees and other beneficial insects are less active. Do not apply near fish ponds etc. Stay out of the damp foliage until it dries. Effectiveness duration depends on growth rate and temperature. In most areas, reapplication may be needed every two to three weeks.
Because the lesser canna leaf roller is not exposed directly to a typical dust or spray, a systemic control is the most useful. BT may work fine for the greater canna leaf roller because if openly feeds on exposed leaves but it does require frequent application. It seldom reaches the lesser leaf roller.
I have never seen phytotoxic injury from acephate on cannas. I am not familiar with the product brand listed so please read and follow instructions carefully.

Kent

"Lesser canna leaf roller," that's the one, thanks.

Kent, do you add a surfactant to your spray? Maybe a mild dish soap? How much? Thanks, Lou

I have always used a surfactant (wetting agent) with acephate. Of course I have/had access to commercial surfactants but you are correct in suggesting a mild soap. As I recall, others have use liquid Ivory soap. I think you might try about a tablespoon to a gallon. There should be a slight sudsing action but not like washing dishes!! Kent