Will these beetles kill my plant?

If left untreated for several seasons, heavy defoliation can weaken the plant and make it susceptible to other diseases. However, a healthy Blackhaw Viburnum can usually recover from a single season of light damage.

Can I use systemic pesticides?

Systemic pesticides can be effective, but they often harm beneficial pollinators that visit your viburnum flowers. It is much better to stick with insecticidal soaps or manual removal.

Blackhaw Viburnum: pests, causes and fixes

Check these first

Inspect the undersides of the leaves for larvae.
Look for skeletonized leaf tissue.
Check for adult beetles feeding on the foliage.

Likely causes

Viburnum leaf beetle
Most likely
How to tell: You will see skeletonized leaves where only the veins remain, or small circular holes. Look closely at the underside of the leaves for tiny, dark, slug like larvae.
What to do: Prune away and destroy any infested branches immediately. For larger infestations, apply an insecticidal soap or neem oil spray to the undersides of the leaves every 7 to 10 days until the pests are gone.
General leaf chewers
Possible
How to tell: Irregular jagged edges or larger bites taken out of the leaf margins. This is often caused by caterpillars or Japanese beetles.
What to do: Hand pick the insects off the plant in the early morning when they are sluggish. If the damage is widespread, use a targeted organic pesticide like Bacillus thuringiensis.

Pests on other plants

Find out what's wrong with your blackhaw viburnum

The list above covers the usual causes. Pocket Botanist looks at a photo of your actual plant and tells you the likely cause, how serious it is, and what to try first. Identification and a health check are free.

When to worry

Worry if more than 20 percent of the foliage is being consumed, as this stresses the plant. Minor nibbling is usually not a threat to a healthy, established shrub.

Stopping it coming back

Keep your shrub healthy with proper watering and prune out any twigs with egg masses in the late winter.

Blackhaw Viburnum: pests? Check yours with a photo

Every plant is a little different. Take a photo of your blackhaw viburnum and Pocket Botanist tells you which cause is most likely, how serious it is, and what to try first. A few checks a day are free. Save the plant and you get care reminders timed for it.

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Questions people ask

Will these beetles kill my plant?: If left untreated for several seasons, heavy defoliation can weaken the plant and make it susceptible to other diseases. However, a healthy Blackhaw Viburnum can usually recover from a single season of light damage.
Can I use systemic pesticides?: Systemic pesticides can be effective, but they often harm beneficial pollinators that visit your viburnum flowers. It is much better to stick with insecticidal soaps or manual removal.

Guides to these causes

Viburnum Leaf Beetle

Why are there holes in my Blackhaw Viburnum leaves?