Depends how large the shrub is, Provado Ultimate Bug Killer is effective but it would be difficult and expensive to spray a large shrub. I used it on my standard Viburnum tinus and it worked but I had my large 6ft shrub removed.

If this has happened 3 years consecutively, your viburnum may lack the energy reserve to re-foliate yet again - making it more susceptible to other problems.

Eggs are laid by adults in late summer on the tips of year-old growth. These hatch in late spring/early summer, the tiny larvae feasting unseen on the backs of leaves, reducing them to “lace”, before going down into the ground beneath the bushes to pupate. A new generation of adult beetles then emerges for another feeding frenzy before laying eggs, and so the whole merry-go-round goes on and on if you don’t interrupt things by spraying or pruning. You need to spray twice, therefore: in early May and early August.

Thanks, Jatkaty, This shrub is at the end of an 8ft high mixed hedge and is about 8ft in circumference.
Thank you Bathgate for explaining how the little blighters live and work! It makes me feel I have little choice but to sacrifice the shrub especially if it would be very expensive to spray it. It will leave a huge space at the end of the hedge where it meets the pavement and it will take a long time for anything to grow to replace it.

I got rid of the dreaded beetle (at least for now) by cutting the bush back really hard the winter before last, and burning all the prunings. It's back to its healthy self now. I don't like to spray insecticide around.

Landgirl, I don't like insecticides either but in any case, this shrub is too large to spray effectively,I think, in view if what Bathgate has explained, I will have to take it out. It's interesting that yours seems fine after a hard prune. I'm thinking things over! Thanks for your nelp.

Now I'm worried about my own viburnums. I'd hate for anything to happen to them.