Flea Beetle - treat or leave alone?

Sheps

After cutting back all the spent flowering stems on the Bowles Mauve yesterday, I noticed that both plants have a large infestation of Flea Beetle, this is probably the reason why they have done so poorly in the flower department.

So, with the plants being in such poor condition and no longer any use to pollinators as they have no flowers, would you replace the plants or give them a chance and treat the Flea Beetle?

izzy8

Can you cut it back and use some good pieces for cuttings, I've found that they root easily

Sheps

The plan is to take a few cuttings if I can't salvage the plant.

Fire

I don't know, but lovely pictures.

Sheps

Thanks @Fire the second image really shows the damage they can cause.