Key Features
- Holes in leaves
- Egg bumps laid on stems.
- Golden brown beetles
Symptoms
Beetles defoliate certain species of viburnum. Wintering as eggs on stems, larvae hatch in May to feed on leaves. Young larvae chew small holes and skeletonize leaves. Golden brown brown beetles appear in mid July and will feed on leaves until frost.
Biology
Beetles winter as eggs on stems. Eggs hatch in May into green larvae that skeletonize leaves. In late June and early July larvae will drop to the ground and pupate. About 10 days later in mid July adults will emerge and feed on leaves. Adults continue to feed on leaves for the remainder of the summer until frost and will lay eggs on twigs. Beetles are common in the North Eastern states, but rare in IL, MI, OH.
Management Recommendations
In dormant season remove stems with obvious egg masses. In March prior to bud break, apply horticulture oil at the dormant rate (4%) to kill eggs glued to stems. When larvae are present on leaves 2% applications of insecticidal soap or spinosad will kill larvae. These two methods are preferred because they allow beneficial insects to kill much of the remaining populations. Other products can be used to kill adults and larvae but care should be taken to avoid applying product when shrubs are in flower and bees and other pollinators are foraging. Plant resistant species (not Arrowwood and Cranberry bush viburnum) in areas where Viburnum leaf beetles are a problem. If you find this pest in Indiana report this pest to 1-866-NO-EXOTIC.
Effective Pesticides
Active Ingredients include: Bifenthrin, Horticultural oil (Paraffinic or superior oil) , Insecticidal soap (Potassium salt of fatty acid), Lambda- cyhalothrin, Spinosad
Resources
- Not satisfied with ID? Contact the Purdue Plant and Pest Diagnostic Lab
- Sign Up for the Purdue Landscape Report
