Asiatic lilies are members of the Liliaceae, or lily, family. The plant is an herbaceous perennial grown from a bulb. Over 100 species of hybrids exist. Although the Asiatic has always been a favorite among gardeners, a pest has arrived that is particular to this type of lily. The red lily bug, or lily leaf beetle, has quickly spread across Eastern Canada and has now made its way into the United States.
The red lily bug (Lilioceris lilii), as an adult, has a striking red body with black legs, head and antennae. The adults are ¼ inch to 3/8 inch long and emit a squeaking noise when squeezed. This is a defense mechanism against predators. They are sturdy fliers and exceptional hiders.
The bugs winter in the ground as adults and appear early in the spring to look for food. They can survive for a couple of weeks until they lay their eggs in a crooked line on the underside of a lily leaf. An adult female can lay up to 450 eggs. The eggs are reddish/orange in color and take seven to 10 days to hatch. They hatch into the larvae stage, which is when they do their most destruction. Young larvae are distinctive in that they secrete and carry their own excrement on their backs. After feasting for 16 to 24 days, they enter the soil for 16 to 22 more days and emerge as adults.
The adults and older larvae do the most destruction to the lily. They eat leaves, stems, buds and flowers. The larvae tend to do more damage then the adults. It's possible they can eat all the leaves off a large lily in only a few days. As adults they will then feed until fall. This can cause severe damage to lilies.
Manual control is the easiest method if only a few bugs are on each plant. Hand picking is effective. It is not dangerous to touch them, but using a pliers or some sort of pinching tool to grab them is preferable. Otherwise, they can be shaken off the plant into soapy water where they will die. The eggs are easy to see on the underside of the leaf; simply wiping off the leaf will destroy the eggs.
Control with pesticides is also an option. If insecticidal soaps (just soap and water) doesn't work then a low toxicity option is "Trounce", a mixture of insecticidal soap and pyrethrin used as a spray. Neem, an insecticide from the neem tree can also be tried. Neem can be bought under the names Turplex, Azatin EC, Margosan-O, Align, and BioNeem. Otherwise, more toxic insecticides such as carbaryl (Sevin) and Malathion are also effective. These can all be bought at local nurseries and garden centers. Instructions should be read carefully before applying.