Pest Status: Elm leaf beetles can defoliate elm trees when populations are high. They are also attracted to homes in late fall where they can become nuisance pests when they occur in great numbers.
Appearance: Adults are about 1/4-inch long and elongated in shape. They vary from yellow when young to olive green when mature, with a black stripe along the outer edge of the wing covers. There are four black spots on the thorax.
Life Cycle: Adults overwinter and lay yellow eggs on elm leaves in the spring. After feeding in the canopy for several weeks, the larvae crawl down the tree trunk and develop into pupae.
Where to Collect: Adults overwinter in bark, litter, and woodpiles or in buildings. In the spring and summer, they can be found feeding on the leaves of elm trees.
Purdue Extension Entomology, 901 West State Street, West Lafayette, IN 47907 USA, (765) 494-4554