The red Beetles have been at several varieties of plant life including what you mentioned and Solomens Seal.
I use Bayer Tree and Shrub insect killer for an early drench,then Sevin duering the mid season to kill adults.
If you drench for a few years it will cut down on the population.
Ihave been drenching for 3 of the 5 years here and only say 1 beetle last year.
There are other pests that make holes in lily leaves.The Red Beetle will destroy the whole plant.