This summer, if you see damage to the leaves, buds and flowers of your lilies, you may have an infestation of lily leaf beetles.
The lily leaf beetle loves to feed on Lilium sp. (true lilies: Turk’s cap, Tiger, Easter, Asiatic and Oriental lilies) and Fritillaria sp.; have been known to feed on Solomon’s seal and Indian cucumber root and lightly “taste” other plants such as nightshade bittersweet, potato, hollyhock and hosta spp.
Your daylilies are safe because they don’t like them!
The adult lily leaf beetle overwinters in the soil. In early spring it emerges, forages on your lily leaves, mates and lays it eggs… generally on the undersides of the lily or fritillary leaves.
The eggs hatch and the larvae feed voraciously on the leaves, buds and flowers of the lilies.
When the larvae are ready to pupate they drop to the ground and burrow into the soil. Pupation takes about 20 days. The adults emerge and are ready to continue eating your lilies!
The lily leaf beetle, (Lilioceris lilii), is thought to be native to Asia and was first discovered in North America near Montreal.
The adult beetle is a beautiful scarlet color with black underside and legs. If you squeeze it slightly when you pick it up, it will squeak in hopes that you will drop it.
Adult beetles will jump off the plant if even slightly disturbed.
Adult beetles are strong fliers so can find your lilies from a long ways away.
The larvae cover themselves with their own feces to deter predators and protect themselves from the sun.
What can you do if you have lily leaf beetles?
plant resistant plants – things they don’t like
don’t import plants from infested areas
knowing the life cycle of the beetle will help in detecting its presence early
hand pick the adults, larvae and eggs. Since the adults will jump off the plant when disturbed, hold a bucket of soapy water under the plant to capture the beetles
there are chemical products that can be used to help control the lily leaf beetle. Before use, be aware of the impact chemicals can have on other insects and wildlife