I've had a bad infestation of root mealy's on are clump of Arisaemas. They were not thriving so I dug them up and lo and behold there they were. Dug them up and dusted with pyrethins and replanted in a different spot and everything looks fine now. There is an image on the Wiki Wiki of the root mealys or is it mealies. http://pacificbulbsociety.org/pbswiki/index.php/… Regarding the insecticide Merit. I have a bottle of the liquid form. Any suggestions about how to treat potted plants. They give instructions for outdoor plants based on trunk size. Arnold New Jersey 56 F today