Adults emerge from their overwintering quarters during late April to early May, fly to nearby elms, mate, and lay eggs. The adults eat small, circular holes in the expanding leaves. A female will lay 600 to 800 eggs in her lifetime. Small black larvae feed on the undersurface of the leaves for about three weeks. Larvae feed in groups, eating the undersides of the leaves, leaving only the upper leaf surface intact, giving a skeletonized appearance.
Adults emerge in about eight days and lay second generation eggs.
In Oklahoma, there are three full generations and sometimes a partial or complete fourth generation of elm leaf beetles. Adults are about one-fourth inch long, yellow to olive green, with dark stripes along the outer edge of each wing cover. Mature larvae are about one-half inch in length, dull yellow, with two black stripes down the back. Ornamental and Lawn Pest Control .