Having perused the results of a search here on leafrollers, I'm left with the impression that orthene / acephate is the most effective control, followed by BT. I've found a Bonide product, Systemic Insect Control, a concentrate containing 9.4% acephate. Is this what I need? The only leafroller listed in the product use guide is "oblique banded leafrollers," which may not be the ones I need to be concerned about. The guide also doesn't list canna as an appropriate plant for use of the product.
Anyone have any idea how long it takes this stuff to become effective, or whether overtreatment can damage a plant?