Adult beetles spend the winter in protected sites, occasionally in homes. In about 7 days, small black larvae hatch and feed on the underside of leaves. Mature larvae crawl down the tree trunk and pupate in the soil at the base of the tree. Adult beetles emerge from pupae in about 14 days. Three or more generations can occur per year.
Mouthparts are for chewing.
This is an introduced species that feeds on elm tree varieties, especially the Siberian and European elms. Cedar elm, American elm and winged elm are less susceptible when other hosts are available. Larvae skeletonize foliage by removing the parts of the leaves between the leaf veins, leaving the upper leaf surface intact. Injured portions of leaves soon turn rusty, reddish-brown, and dry skeletonized leaves fall to the ground. Adults eat roughly circular holes in leaves.