Lily Leaf Beetle—Lilioceris lilii

The lily leaf beetle is an invasive species that dines on and destroys ornamental lily plants. Both adults and larvae do serious damage to plants. Adult beetles overwinter in the soil or plant debris in the garden or woods, sometimes a distance away from the host plants. Adults prefer environments that are shaded, protected, cool, and moist.

Lily leaf beetles will taste or feed lightly on many plants including Lilium spp., Fritillaria spp., Polygonatum spp. (Solomon's seal), Solanum dulcamara (bittersweet nightshade), S. tuberosum (potato), Smilax spp., Nicotiana spp. and other plants. However, they will only lay eggs and develop on Liliuim species (Turk's cap lilies, tiger lilies, Easter lilies, Asiatic and Oriental lilies), and species of Fritillaria.

lily leaf beetle adult
The lily leaf beetle adult has a bright scarlet body and black legs, head, antennae, and undersurface. The adults are about ¼ inch long, and they will squeak if they are squeezed gently–a defense mechanism to deter predators.

Damage to lily plant from lily leaf beetle
Adults and older larvae feed on leaves, stems, buds, and flowers of the host plant.

lily leaf beetle larvae
Larvae resemble slugs with swollen orange, brown, yellowish or even greenish bodies and black heads. Larvae tend to cause more damage than adults.

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Identification and Control Information

[Photos, left to right: Lisa Tewksbury, University of Rhode Island,; Richard A. Casagrande, University of Rhode Island,; Leslie J. Mehrhoff, University of Connecticut,]