Beetles, Invasive Species

Viburnum Leaf Beetle

Note: A factsheet with additional information about the Virburnum Leaf Beetle can be found here.

One of Wisconsin’s newest invasive species has been popping up in Milwaukee and Ozaukee counties this spring and summer.  The invasive Viburnum Leaf Beetle  (VLB) is originally from Europe and was first detected in North America in eastern Canada in the 1940’s.  By the 1990’s, it had been detected in New England and is now scattered across much of the northeastern part of the country.  This insect can cause significant damage to viburnums.  In some cases, entire plants can be defoliated and plant death can occur.

An isolated infestation of viburnum leaf beetle was detected in Dane Co. in 2009, but was quickly eradicated.  Last summer, VLB was detected in Glendale (Milwaukee county) on a mature plant and has since been found on other viburnums in area .

VLB Damage
Feeding damage from adult viburnum leaf beetles. Photo courtesy of Paul Weston, Cornell University, Bugwood.org

The larvae (up to 1/3″ long; yellowish in color with black spots and dashes) and adults (~1/4″ long; yellowish-brown beetles) can cause significant damage to viburnum plants, especially Cranberrybush and Arrowwood viburnums.

VLB Larvae
Viburnum leaf beetle larvae. Photos courtesy of Paul Weston, Cornell University, Bugwood.org.
VLB Adult
Adult viburnum leaf beetle. Photos courtesy of Paul Weston, Cornell University, Bugwood.org.

At this point, all of the known finds are confined to northern Milwaukee county and southern Ozaukee county, but gardeners, landscapers, and residents in southeastern Wisconsin should keep an eye out for this highly damaging pest!

A UW-Extension factsheet with additional information can be found here.