By: Jenny Eder, Lincoln County Master Gardener Volunteer
It is that time of the year to be on the lookout for the Lily Leaf Beetle. In spring, the adult beetle emerges from the soil to lay its eggs on plants of the Lilium (true lily) or Fitillara families. Common names include the Easter Lilies, Asiatic, Oriental, tiger lilies and the native Wood Lily. It does not include the variety of plants that are classified as daylilies. Adult beetles can be found feeding on potato plants, hollyhocks, hostas, and Solomon’s seal but will only use the Lilium or Fitillara family of plants to lay its eggs.
The Lily Leaf Beetle has one life cycle during a season. The bright red adult beetle will lay orangish tan colored eggs on the underside of the leaves. The eggs hatch in one to two weeks. The larva is orange to light green with a slug like appearance. Most larva will appear black in color since it puts its excrement on its back. It is thought they do this to help ward off its enemies. After feeding, the larva will drop into the soil to pupate and emerge as an adult to continue feeding until Winter. Unfortunately, there are no known native natural enemies.
Gardeners can help control the spread of the Lily Leaf Beetle by inspecting plants often. For an effective non chemical control, hand remove and place adults or larva in a bucket of soapy water. For chemical control, look for garden sprays with insecticides labeled for ornamentals. Read the entire label and apply as directed to ensure proper use. Keep checking your plants often during the season as a female can lay up to 450 eggs during the summer.
To help document the spread of the Lily Leaf Beetle, if you should encounter the Lily Leaf Beetle in your garden, please contact the Lincoln County UW-Extension at 801 N. Sales Street, Suite 101, Merrill or at 715-539-1072. The UW Extension office also can provide additional information on this newer garden pest.
The Lincoln County UW-Extension Master Gardener Volunteers are now answering questions through their phone number: 715-539-1073 or through their email: [email protected]. You may also bring samples to the UW-Extension office for identification.