Skimmia Leaves turning white

My skimmia is looking sickly as the green leaves turn to a milky white. I took a leaf to a local garden centre and they told me it was because some insect had sapped the nutrients from it and that I should apply rhododendron food. I did that and it hasn’t helped. Anyone have any idea of what the problem is and how to fix it?

 

Likely Skimmia spider-mites.

The advice to use fertilizer is counter to the suggestions here: Skimmia Pests

"Citrus red mites love nitrogen. Excessive fertilization plus drought equals increased citrus mite fertility. Keep skimmia in partial or full shade and apply mulch over the soil to help lock in moisture. Go easy on the fertilizer, and keep the skimmia well-watered to discourage egg-laying. Blast off visible mites with a hose."

Other than that, you'll have to wait for those leaves to fall and be replaced by new ones.

 

Thank you so much for your advise. There is no evidence of mites on any of the leaves.

 

See lower-right photo on this page:

Skimmia japonica | Landscape Plants | Oregon State University

 

I see. Damage was probably done last year and the little critters have gone to “greener” pastures, leaving their damage behind. Mulch and water it is then. But since it hit the whole plant and it will most likely loose all its leaves, it might mean I will need to replace it or deal with a dead looking plant next spring. Thank you for your help!