Tea scale, Fiorinia theae, is common on camellias. It is an armored scale that lives on the underside of leaves. You can find it on almost any camellia by looking for inner leaves that have yellow spots on top. When you turn it over you will see tan canoe-shaped scale covers and some white fluff from the males. These are tough to treat because the heaviest infestations are often deep within the foliage of large bushes. They have multiple generations per year that start to overlap. The crawlers are very small but you can seem with the help of a decent loupe. They are yellow with black eyes. When I was flipping scale covers last night about half had crawlers wriggling under the cover and half just had eggs. A few crawlers were out on the leaf trying to find a spot to feed. So it is early in the hatching at least around campus. You can find a Insect Note with more information and recommendations here.