These little buggers eat up my cannas (and the blooms on my crepe myrtles). The bags (as I found out the hard way) aren't bery effective. Seven Dust works o.k. on lower leaves, but sine cannas are upward-facing, it slides down adn they eat the top leaves. Any suggestions?!?!? Love my cannas, but I'm tire of fighting the J.B.'s!!!!!!!