HELP! small (1/4 inch) flat soft cottony white cocoons on underside of leaves of my young cherry tree, also appearing on the neighbour's shrubs. I haven't seen the adults but the leaves are riddled with holes and I have been pruning the branches with too many cocoons. I can squash them by hand but they are well stuck to the leaves. Adults lay eggs on or under the bark of young branches, causing blisters that are also squashable. Some leaves have just one cocoon, others have numerous.