The lily leaf beetle (LLB), Lilioceris lilii, is a bright red beetle in the chrysomelid family native to Europe and Eurasia. In its native range, LLB is a pest of exotic and hybrid lilies. Researchers in the eastern United States have found Asiatic lily hybrids to be most susceptible to LLB while some Oriental varieties are resistant. Lilium henryi ‘Madame Butterfly’, L. speciosum ‘Uchida’, L. ‘Black beauty’, L. regale and L. ‘Golden Joy’ appear to be most resistant.
Adult beetles overwinter in the soil and emerge in the spring to feed on developing foliage and seek mates. Adult beetles are very active and mobile, and they make a defensive chirping or squeaking noise when provoked. Mated adult females lay eggs in small batches in irregular rows…laying up to 450 eggs during the season. Newly emerged larvae feed on the undersides of leaves. As larvae mature, feeding damage becomes more apparent on older leaves and sometimes stems and flowers.
See Todd Murray’s “Pest Watch: Lily Leaf Beetle.” http://pubs.extension.wsu.edu/pest-watch-lily-leaf-beetle-home-garden-series