Weed and Insect Management
Leaf feeding by insects on ornamental plants is common. This feeding damage is usually superficial and hardly noticeable. In such cases, control is not necessary. Beneficial predators, parasitoids, pathogens and unfavorable weather are all factors that help to regulate insect defoliator populations. Occasionally, more noticeable leaf feeding damage or considerable webbing occurs. While unsightly, this moderate feeding damage or webbing does not generally harm trees or shrubs. Common defoliators include moth caterpillars (Order Lepidoptera), sawfly larvae (Order Hymenoptera) and beetle larvae and adults (Order Coleoptera).
"SP609-Insect Defoliators of Ornamental Trees and Shrubs," The University of Tennessee Agricultural Extension Service, SP 609 - 12M - 7/03 R12-4910-034-001-04, http://trace.tennessee.edu/utk_agexcomhort/25