Viburnum in pot

I have a viburnum which has never flowered in a pot.  I haven't been into the garden much recently (long story) but I have just noticed it and the leaves look like lace which I presume is viburnum beetle.  Can I just cut it right back or will I have to use new compost and repot  or should I give it up as a bad job.  I have two other viburnums one in the ground and another in a pot.  A few of the leaves look as if they have been damaged but nothing like the other I mentioned. and I am going to spray to see if it helps.  I can't see any sign of the beetle.  Many thanks