Female beetles then lay eggs in clusters on the bottom of leaves. Soon after the eggs hatch, small, black larvae begin to feed. At the end of four to six weeks, these larvae migrate to the ground and the transformation to the adult stage takes place. Adults return to adjacent trees and the life cycle begins again. Damage to the elm trees is usually not as serious as it looks.
Elms are usually able to produce enough new leaves to ensure food production.
However, heavy infestations of elm leaf beetles occurring several years in a row may eventually result in tree deaths. The insects may become a nuisance to homeowners in the fall. The onset of cold weather forces adults to seek overwintering sites. Secluded areas such as attics or basements may attract hundreds of beetles. Homeowners are seldom pleased with the uninvited guests.