Spider Mites frequently attack Photinia, Boxwood, and Italian Cypress. They can be very hard to see on the leaf. Many times you can shake them off a leaf and onto a white sheet of paper. This makes them easier to see. If you want to verify that is is not just dust, squash a few specks on the paper and try to smear them across the page. A red streak across the page pretty much confirms the spider mites. The leaf above shows the symptomatic, yellow or bronze speckled look on the leaves . Some experts claim a level of control with a hard spray of water to knock the spider mites off the leaves. Oils or a combination of oils and professionally applied insecticides are the most effective measures.
Click the link below for a good overview of spider mites and other insect pests by TAMU Ag Extension