Viburnum Leaf Beetle has now been found at the Chicago Botanic Garden. It’s also been found in other parts of the Chicago metro area including Cook and DuPage County since 2009. It seems like tree varieties such as Arrowwood, Possum-haw and Cranberrybush are becoming most susceptible to this threat.
This pest overwinters as eggs on host twigs. They remain on twigs until May, when they hatch. By early to mid-June, larvae drop to the ground, pupate, and remain in the soil for about ten days. Adults usually emerge during mid- to late July, and may be observed until the first frost. It takes eight to ten weeks for this species to complete development from egg to adult. Females deposit several eggs on the tips of the branches from late summer to fall. They chew holes in the bark to deposit eggs and then cover them with excrement and fragments of chewed bark and wood. Initially, there is a sharp contrast between the excrement and the pieces of wood. A female may lay up to 500 eggs. There is only one generation per year.
Read more at: Penn State University