Viburnum Leaf Beetle, Pyrrhalta viburni, is a new invasive species that is making its way down the East Coast and could wreak havoc on both native and imported species of Viburnum in DC, Maryland, and Northern VA. Both the larvae and adult beetles feed on foliage creating severe damage and eventually killing the plant. The good news is that Viburnum Leaf Beetles will only infest Viburnums. The bad news is that Viburnums are very popular and commonly used as a landscape plant because of their showy flowers, berries, and fragrance.
The Viburnum Leaf Beetle is an invasive beetle from Europe that was first found in Upstate New York in 1996. Since then it’s spread to Maine, Vermont, Ohio, Pennsylvania, and most recently Western Maryland in 2014. Although it has not yet been officially spotted in Virginia or DC, researchers warn that it’s a matter of time before homeowners start spotting these on their property in VA and DC as well. Our Arborist suggest keeping an eye out for signs of Viburnum Leaf Beetles and take steps to prepare your property to be resistant to this invasive pest.
Species of Viburnum That Are Highly Susceptible:
Arrowwood viburnums, Smooth witherod viburnum, European cranberrybush viburnum, American cranberrybush viburnum, Chinese viburnum, Taiwanese viburnum, Rafinesque viburnum.
Species of Viburnum That Are Susceptible:
Mapleleaf viburnum, Wayfaring tree viburnum, Rusty blackhaw, Southern black-haw, Sargent viburnum, Wright viburnum
Species of Viburnum That Are Resistant:
Dawn viburnum, Koreanspice viburnum, David viburnum, Judd viburnum, Doublefile viburnum, Leatherleaf viburnum, Tea viburnum, Siebold viburnum.
Signs Of Viburnum Leaf Beetle:
Both larvae and adult beetles feed on the foliage of Viburnum creating severe damage and eventually killing the plant. The Larvae tend to skeletonize the leaves while adults create oblong holes. Keep an eye out for the symptoms and signs below:
- Skeletonized Leaves (Typically May-June)
- Oblong Holes In Leaves (Typically June-September)
- Adult Beetles on Leaves (brown and about ¼ inch in length)
- Egg Masses (Dark Caps On Twigs & Stems)
- Overall Decline In Health
- Larvae on Leaves
How To Treat Viburnum Leaf Beetle:
Insecticides: Once infested, Arborists can use insecticides to combat and manage the Viburnum Leaf Beetle population.
Pruning:If egg masses are spotted early, we may be able to prune them out of the plant before they hatch and cause damage. If the infestation is too severe pruning may not be an option and insecticides may need to be used.
Resistant Species: Since homeowners have time to prepare for this invasive species we suggest you only invest in Viburnum species that are resistant to this invasive pest. By planting resistant species on your property you will skip the headache of having to deal with Viburnum Leaf Beetles when they start infesting plants in the area. Viburnum Leaf Beetle resistant species include Dawn viburnum, Koreanspice viburnum, David viburnum, Judd viburnum, Doublefile viburnum, Leatherleaf viburnum, Tea viburnum, and Siebold viburnum.
Overall Health: If you have a species of Viburnum on your property that is susceptible to this pest you should make sure to keep your property healthy overall. Keeping your plants healthy will help reduce the risk of infestation and reduce the risk of the plant dying from an infestation. To keep your VIburnum and other plants healthy invest in a Canopy Protection Plan.
Preventative Treatment: Once the insect is confirmed in our area, your Arborist may suggest you use preventative insecticide treatments to prevent infestation as well.
If you spot signs of Viburnum Leaf Beetle on your Viburnums or notice any insect activity on your other trees and shrubs, give us a call. Our Arborists can meet with you to help diagnose this issue or any other issues on your property and create a treatment plan that meets your needs. To meet with one of our Arborists give us a call at 703-573-3029 or book an appointment through our online booking system.