The viburnum genus is a large group of plants consisting of more than 150 species. They include deciduous as well as evergreen shrubs and small trees ranging from 2 feet to 30 feet in height. One thing they have in common is an enemy: the viburnum leaf beetle. If you love your viburnum hedge, then you will want to know all about the viburnum leaf beetle. The larva of these beetles alone can strip viburnum leaves very quickly. In this article, we will identify the viburnum leaf beetle, review its life cycle, and provide some tips on treatment. If you prefer to leave the work to trained professionals, then call Timber Ridge Tree Care to schedule an appointment. We offer a host of tree services as well as tree removal.
The aptly named viburnum leaf beetle is a pest that feeds exclusively on viburnum leaves. Adult viburnum leaf beetles are about a quarter of an inch long while larvae can be up to a third of an inch long. Adults are yellowish brown in color, and larvae range from yellowish green to light brown with black spots and dashes on their body.
Viburnum leaf beetle larvae start their destruction in the spring, chewing holes in leaves that create a lace-like pattern. Adult viburnum leaf beetles get to work in late June and early July, chewing oblong holes in the leaves. Severe infestations can completely defoliate viburnum shrubs, weakening the plant and potentially causing its death.
Fortunately, there is only one generation of these pests per year. Larvae can be expected to appear in early- to mid-May and pass through three stages as they feed for several weeks. Once June rolls around, the larvae pupate in the soil until emerging as adults by late June or early July. These will continue chewing on viburnum leaves. Females chew small pits in twigs and deposit several eggs into each pit before covering the pits with tiny pieces of chewed wood. Each female can deposit around 500 eggs, which stay in place through the winter until they hatch the following spring.
If you do not want to deal with viburnum leaf beetles, then consider viburnums that have shown resistance against viburnum leaf beetles. These species include the doublefile viburnum, Judd viburnum, and Koreanspice viburnum. You want to avoid arrowwood viburnum and American cranberrybush viburnum as these are preferred by viburnum leaf beetles.
In any case, examine your viburnum’s twigs for egg-laying sites. Prune and destroy infested twigs by burning them. You can also invite natural viburnum leaf beetle predators. These include lady beetles, assassin bugs, and green lacewings.
If there is a severe infestation, you can also use chemical treatments to reduce the number of eggs that will hatch.
The folks at Timber Ridge Tree Care are happy to help with pest & disease management. Our live representatives are on standby to take your call and schedule a convenient appointment.