Laboratory Services Division, University of Guelph
95 Stone Rd. West
Guelph, Ontario N1H 8J7
Phone: (519) 767-6256 Fax: (519) 767-6240
E-mail: pdc@lsd.uoguelph.ca
THE LILY LEAF BEETLE
(Coleoptera:
Chrysomelidae)
The lily leaf beetle, Lilioceris
lilii (Scopolie), is native to Europe and North Africa. It was found
in Montreal (QC), 1945, and since then has been reported throughout Ontario
where lilies are grown.
The lily leaf beetle is a distinctive, though minor, pest in Canada. The adult's elytra (wing covers) are shiny and bright red, contrasting the beetle's black antennae, eyes, head, legs, and underside. The beetle varies in length from about 6 to 8 mm. It has 11-segmented antennae, notched eyes, and two visible indentations on the thorax. The adult is able to produce chirping sounds by means of a wing cover and abdominal stridulatory apparatus. It may do so when picked up.
Life History
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The lily leaf beetle over winter in soil and plant debris. In early spring, the adults emerge to mate and lay eggs. The female lays between 200 and 300 eggs on the underside of leaves in clumps or irregular rows of 2-10 eggs. Some females can survive to lay eggs over two successive years. Incubation of the eggs takes between 5 and 10 days. The newly hatched larvae feed on the underside of leaves while mature larvae feed on the upper surface of the leaves. The larval stage lasts 16-24 days and the larvae are typically covered with a protective case of excrement. The pupal stage lasts 20-25 days and occurs in the soil within a secreted cocoon. There are between 1 to 3 generations per year.
Host Plants
The lily leaf beetle is a pest of lily species (Lilium sp.), lily of the valley (Convallaria majalis), Solomon's seal (Polygonatum multiflorum), in addition to the fritillary (Fritillaria sp.).
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Lily leaf beetle damage |
Control
The beetle can be controlled by handpicking the adults and larvae, and destroying any eggs that are found. When transplanting susceptible plants, care must be taken not to introduce the beetles to a new location. Since the lily leaf beetle is a localized and a minor pest in Canada, there are no specifically registered chemicals for their control. However, domestic insecticides containing carbaryl, methoxychlor and rotenone are registered for general leaf beetle control on ornamentals may be used.
Ian Smith
PDCF-056 (Revised 2003/01/14)