Red Lily Beetle
In the garden: True lilies, their hybrids and fritillaries
Most temperate regions
Red lily beetles and their larvae are leaf and flower eating pests of both true lilies and fritillaries. The adult beetles are 8mm in length and have bright red wing cases and thoraxes. The head, body and legs are black. Adult beetles overwinter in the soil and emerge in spring to mate and lay clusters of orange, elongated eggs on the undersides of new leaves on their host plants. Eggs hatch into larvae which feed on the leaves and can grow to 8mm in length. Larvae are usually covered in their own slimy black excrement. When fully grown, the larvae burrow into the soil to pupate.
Adult red lily beetles feed on leaves, flowers and seed pods, creating oval-shaped holes. The larvae mainly feed on the leaves, starting at the tip and working their way back to the stem. Stems, flowers and seedpods can also be damaged by the larvae.
Regularly search through plants from mid-spring onwards and remove any adults, larvae and eggs that can be found. Plants that are grown in pots can be repotted in the winter into fresh clean soil in order to remove any overwintering adults.
Regular removal of adults, larvae and eggs by hand will help to manage red lily beetle outbreaks. Where the infestations are severe, as a last resort organic Pyrethrum-based products are available from garden suppliers. These will need to be applied following the label instructions.
Be aware that red lily beetles use an alarm pheromone to alert other beetles to escape capture and predation. Adult beetles will fall to the ground when they detect this pheromone and will lay still with their black undersides facing upwards, making them difficult to find.