McAdam Horticulturist Gives Tips to Battle Viburnum Leaf Beetle

Until three years ago, the viburnum leaf beetle was virtually non-existent in the Chicago area. But today, it has become a household name—and for all the wrong reasons.

Scott McAdam Jr., a horticulturist at McAdam Landscaping, notes that even if you are unaware of this tiny beetle, chances are you have seen the havoc that has resulted from their aggressive feeding habits, primarily on Arrowwood viburnum.

“Arrowwood viburnum is a very common landscape plant due to its ornamental character, hedge qualities, and rapid growth rates,” says McAdam. “Unfortunately, it is also a highly susceptible species. Because of the number of these plants in the landscape, there is a constant food source and the damage is seen with regularity.”

The beetle, brown and about one-quarter inch in length, has larvae that emerge from eggs laid in the stems and begin their feeding frenzy. Damage can be significant, says McAdam, because there are multiple generations of new larvae throughout the growing season. Both adults and larvae feed on the leaves, setting in motion a season-long feeding cycle that results in continued damage.

If you are not sure if your property is suffering from the effects of viburnum leaf beetle, here’s what to look for, McAdam advises: the “skeletonizing” of the leaves or eating the tissues between the leaf veins.

“Heavy feeding of susceptible species can virtually defoliate the entire plant very rapidly,” says McAdam. “In a matter of days, your plant can go from great health to appearing sparse with highly skeletonized leaves.”

The most highly susceptible species are Arrowwood, American Cranberry Bush, and European Cranberry Bush viburnum. A few key steps to put your plants on the path to proper treatment:

• Plant shrub species that are not susceptible or have some resistance to this insect
• Prune stems that show signs of egg-laying sites
• Contact an arborist to treat the viburnum chemically

Founded in 1979, McAdam Landscaping is a landscape design/build firm based in Forest Park. Its four-acre headquarters is located at 2001 Des Plaines Ave. and includes a Nursery & Garden Center that is open through the end of October.

For more information about McAdam Landscaping, call 708-771-2299, visit www.mcadamlandscape.com or www.facebook.com/McAdamLandscaping.