Cottony Camellia Scale is one of several cottony scales in the genus Pulvinaria. You can find these now on their common hosts including holly and camellia. Flip over leaves and you will see cottony masses about the size of a cotton swap stuck to the bottom of leaves. These are the egg masses. They each contain many hundred eggs that will hatch soon. Note that the holly this ovisac was on is still flowering. Thus, you cannot make foliar applications of neonicotinoids such as imidacloprid, dinotefuran, or thiamethoxan or really most insecticides since bees will be foraging. So check for flowering in a week or two when the eggs actually hatch when choosing your insecticides.