Tea scale, those insects that injure camellias by sucking the juices from the plant, can also discolor foliage. The insects cause the upper leaf surface to have yellow splotches. Look at the undersides of the foliage. If you see whitish spots, you're likely looking at male tea scale. These males will secrete a white, woolylike mass.
Females are dark brown.
Oil emulsion sprays will help control outbreaks. Camellias require a highly organic and slightly acidic soil. Good drainage is a must. November to March is the ideal time to plant camellias. A well-draining spot that receives morning sun and some filtered shade is ideal.