ANNAPOLIS, MD (April 17 2006) - The viburnum leaf beetle, Pyrrhalta viburni, is a recent unintentionally
introduced pest of viburnum in North America. It was first found in upstate
New York in 1996. This pest has been on the move ever since munching its way
through native and landscape viburnums from upstate New York to northern
Pennsylvania. It has not reached Maryland yet, but we need to be on the
look out for it. This serious pest of native and landscape virburnums has
earned the designation of “Invader of the Month” for April by the Maryland
Invasive Species Council.
Larvae and adults feed on the foliage and can severely damage and eventually
kill some species of viburnum. Larvae hatch in early May initially feeding together
and skeletonizing the underside of leaves. As they grow, they consume the foliage.
High populations may completely defoliate the shrub. Mature larvae are 10-11 mm
long and yellowish-brown with black spots. They pupate in the soil in early to
mid-June. Adult beetles are brown and about 4.5-6.5 mm long. They emerge in July
and are present through September. Adult feeding appears as oblong holes in the
leaves. Females lay eggs in cavities on twigs in late summer and fall. This beetle
is spreading its range and is currently found in New York, Maine, northern
Pennsylvania, Vermont, parts of Ohio, Canadian Maritime provinces, Ontario,
and British Columbia.
Look for egg laying sites on the twigs. Prune these twigs and dispose of
them. The egg masses are easiest to find after viburnums have dropped
their leaves. To control young larvae, monitor for skeletonized new
leaves and use a registered insecticide, if necessary. Some species of
viburnum appear to have resistance to this pest. Plant resistant varieties
of viburnum such as dawn viburnum, V. bodnantense, Koreanspice viburnum,
V. carlesii, David viburnum, V. davidii, Judd viburnum, V. x juddii,
doublefile viburnum, V. plicatum, doublefile viburnum, V. plicatum var.
tomentosum, leatherleaf viburnum, V. rhytidophyllum, tea viburnum, V. setigerum,
and Siebold viburnum, V. sieboldii. Encourage beneficial insects in the landscape.
Several native predators such as the spined soldier bug, and lady beetles feed on
viburnum leaf beetles. Research is underway to explore more biological control
Keep an eye out for feeding damage on viburnum. If you suspect
viburnum leaf beetle, contact Dick Bean, entomologist, at the Maryland
Department of Agriculture at 410-841-5920. You may also contact the
University of Maryland Home and Garden Information Center at 1-800-342-2507
or hgic.umd.edu. For more information on the viburnum leaf beetle visit
Cornell University’s Citizen Science web site at
For more information about other Invasive Species of Concern,
visit www.mdinvasivesp.org or call the
Maryland Department of Agriculture at 410-841-5920.
photos available electronically on request.
VLB adult damage
VLB egg masses
VLB larval damage