Lily Leaf Beetle – What to do about it
If there are holes in the leaves of your lily leaves, the culprit is the Lily Leaf Beetle. This little beetle feeds on true lilies – Asiatic, Trumpet, Oriental and Hybrids of these lilies are all susceptible to this pest.
The adults are active in April and May and are easily spotted. They are bright red with black undersides and about ¼ inch long. You can hand pick them off the lily plants and either squish them or drop them in a cup of water with a couple of drops of dishwashing liquid or you can spray them with a product containing Neem oil.
Eggs are laid on the undersides of the leaves in a row. Destroying the eggs will keep the new generation from hatching. Rub them off the leaves with your fingers. Once the eggs have hatched, the larvae will feed on the leaves of your lilies, shredding them. The larvae carry their fecal material on their backs which makes them unappealing to predators (and the rest of us). Neem sprays are effective in destroying the larvae as well. The adults can fly so be vigilant all summer because if you don’t have the beetles one season, you may find them in following seasons.
Learn more about the Lily Leaf Beetle on this link to the University of Maine, http://umaine.edu/publications/2450e/