Viburnum beetle
A leaf beetle whose creamy-brown larvae reduce viburnum foliage to a lace of veins in late spring, followed by the adults doing the same again in late summer. The two-peaks-with-a-gap pattern is the diagnosis: nothing else attacks a viburnum hard in May, stops in July and starts again in August.
Caused by: Pyrrhalta viburni · also called viburnum leaf beetle
What brings it on
Eggs are laid in pits chewed into the young stems in late summer and hatch the following April, so an infestation carries over on the plant rather than arriving from outside. Deciduous viburnums such as V. opulus and V. tinus are the worst affected.
source
Sourced guidancehigh confidence
- Royal Horticultural Society: Viburnum beetle
- Penn State Extension — Pennsylvania State University: Viburnum leaf beetle
Checked 2026-08-13
Usually seen: April, May, June, August, September
Preventing it
Ordered by how much difference each measure actually makes, not by how often it is repeated.
- Look along the undersides of the youngest twigs in winter for the rows of small raised egg pits, capped with a dark crust, and prune those shoots out. This is the only stage of the year where the whole next generation is in one findable place.
source
Sourced guidancehigh confidence
- Penn State Extension — Pennsylvania State University: Viburnum leaf beetle — management
Checked 2026-08-13
Dealing with it once it is there
- Tolerate it where you can: an established viburnum defoliated in May will refoliate, and repeated years rather than one bad year are what kill a plant. Where it is repeating, remove the egg-bearing twigs in winter rather than spraying the larvae in spring.
source
Sourced guidancemoderate confidence
- Royal Horticultural Society: Viburnum beetle — control
Checked 2026-08-13
What it affects
On sprays and treatments
GrowingHQ does not tell anyone what to apply, at what rate, or how often. Pesticide approvals differ by country, change without notice, and the product label is legally binding — it is also the document you are holding. What is described here is cultural and physical control, which is what a home grower can act on without a label in front of them.