Leaf bronzing is characteristic of spider mite injury. Prolonged feeding reduces leaf photosynthesis.
Mites live underneath the leaves and produce webbing. They are difficult to see with the naked eye.

More Two-Spotted Spider Mite information:
- Notes on Raspberry Insects: Two-spotted Spider Mite – (OMAFRA)
- Spider Mites on Red Raspberry – (Washington State University)
Use these resources if you need additional help with diagnosis and to find solutions to your problem.