Infestations of California red scale, Aonidiella aurantii, are at their lowest levels since this pest first became widespread and seriously damaging in citrus orchards of southern California. Chemical treatments have been eliminated in many areas, and in others, reduced to applications every one to two years. The activities of minute hymenopterous parasites, particularly the golden chalcids, Aphytis melinus and A. lingnanensis, are credited primarily with this reduction of the scale.