Red lily bugs--also called red lily beetles--are bright red beetles that eat the flowers and leaves of lilies and fritillaries. They winter underground and then emerge in the spring when your lilies and fritillaries begin to grow. Just a couple weeks after the adult red lily bugs arrive, they lay their eggs on the underside of the leaves. If you want your flowers to thrive, you must get rid of the red lily bugs as soon as possible.
Soak the soil with dimethoate, an insecticide available at your local nursery. Liberally apply dimethoate all around the soil of your garden where lilies and fritillaries are located. Apply it anytime, but if you had red lily bugs last year, consider applying it early in the spring just before they reappear.
Kill them manually. Use your hands and squeeze them when you see them, or use a pair of pliers. If you are too squeamish for this, then brush them off into a bucket of soapy water.
Use an insecticidal soap or permethrin to kill red lily bug eggs, larvae, and the red lily bugs themselves if your garden is too infected to kill them manually. Both are available in a spray that must be sprayed directly on the bugs, eggs and larvae.