|Lily leaf beetle (Lilioceris lilii) adult - Shelley Barkley|
The lily leaf beetle lays its eggs and develops only on true lilies (Tiger, Easter, Asiatic and Oriental lilies) and fritillaries. They can feed (but not develop) on other perennials like lily-of-the-valley. Adult and larval feeding will ruin true lilies. The feeding damage can be so severe that many gardeners have removed lilies from their landscapes.
The adult beetle overwinters in the soil or leaf litter, not necessarily near host plants. They emerge on the first warm spring days and will begin feeding on the early emerging lilies, as early as mid-April on the Prairies. Shortly after emergence, they start to mate and lay orange eggs in rows of 3-12 on the undersides of the lily leaves or on the emerging lily shoots (late April to early May). Egg laying (up to 450 per female) can continue well into July. Eggs will hatch in 4-8 days.
|Tetrastichus setifer on Lily leaf beetle larva - Shelley Barkley|