Lily Leaf Beetle Likely in Iowa

A bright red lily leaf beetle on the tip of a lily leaf. Photo by Richard A. Casagrande, University of Rhode Island, Bugwood.org.
A bright red lily leaf beetle on the tip of a lily leaf. Photo by Richard A. Casagrande, University of Rhode Island, Bugwood.org.

The Iowa State University Plant and Insect Diagnostic Clinic has confirmed a likely infestation of the lily leaf beetle, Lilioceris lilii, in Cedar Rapids based on photographic evidence and is asking for reports of the invasive insect. 

Multiple lily leaf beetles eating lily leaves. Photo by Leslie J. Mehrhoff, University of Connecticut, Bugwood.org
Multiple lily leaf beetles eating lily leaves. Photo by Leslie J. Mehrhoff, University of Connecticut, Bugwood.org.

This would be the first documented evidence of the beetle in Iowa, not long after the beetle was confirmed in Minnesota earlier this month. The lily leaf beetle, a native of Europe and Asia, first appeared in the U.S. in 1992, and most common in the Northeast.

A lily leaf beetle on a leaf. Photo by Leslie J. Mehrhoff, University of Connecticut, Bugwood.org
A lily leaf beetle on a leaf. Photo by Leslie J. Mehrhoff, University of Connecticut, Bugwood.org.

The adult insects have a distinctively bright red body with a black head, and about ¼-inch-long. They have no spots, stripes or other markings. The larvae are greenish to orange in color, up to 3/8-inch-long and slug-like in appearance and are active from May to June.

The lily leaf beetles are present in the garden from May until September and feed on true lilies (Lilium spp.) and fritillaries (Fritillaria spp.). Adults chew holes in the leaves, feed on the stem, flower buds and flowers. The defoliation caused by the lily leaf beetle can severely damage plants.

They will also feed on lilies of the valley and Solomon’s seal but less often; however, daylilies (Hemerocallis spp.), canna lilies (Canna spp.) and calla lilies (Calla palustris) are not consumed by the invasive insect.

If you spot a possible lily leaf beetle please report sightings here: REPORT LILY LEAF BEETLE SIGHTINGS

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