By Linda Williams, DNR Forest Health Specialist
Linda.Williams@wisconsin.gov or 920-360-0665 

Small brown adult viburnum leaf beetles cause typical defoliation on a leaf. / Photo Credit: Wisconsin DNR

Viburnum leaf beetle (Pyrrhalta viburni) is a relatively new invasive insect in Wisconsin. It originated in Eurasia and was first identified in Wisconsin in 2009.

Adults and larvae feed on the leaves of viburnums and can cause mortality after a few years of repeated defoliation. Feeding causes characteristic holes in the leaves. Beetle numbers can be very high on a single plant.

Viburnum leaf beetle has been observed defoliating native viburnum species including American Highbush Cranberry (Viburnum opulus var. americana) and Mapleleaf Viburnum (Viburnum acerifolium) in forest stands in Iron County and more recently in Oneida County.

A map showing the presence of viburnum leaf beetle in Wisconsin. / Map Credit: University of Wisconsin Insect Diagnostic Lab

Viburnum species vary in susceptibility, with some native viburnums listed as preferred hosts. Cornell University has put together a list of viburnum species and their susceptibility.

Control in natural forests is not practical at this time, and control options have not been developed yet for forested areas, although native predators such as native ladybeetles and lacewings will feed on some viburnum leaf beetle larvae.

For information on controlling viburnum leaf beetles on cultivated viburnums or landscape plants, check out the University of Wisconsin-Madison Extension viburnum leaf beetle webpage or Cornell University’s citizen science viburnum leaf beetle webpage.