The California red scale, Aonidiella aurantii (Maskell) (Hemiptera: Diaspididae) is potentially a severe pest of citrus trees in different parts in Egypt. The aim of this work is to study the biological studies of this pest on the host plants, Citrus sinensis (citrus), Ficus nitida (laurel fig) and Mangifera indica (mango)under different temperatures (18, 24, 30ºC) as well as an annotated list of natural enemies associated with A. aurantii in Egypt. The results observed the host plants and temperatures greatly influenced on the development of A. aurantii.The lowering of the temperature increased the dimension of the California red scale and lengthened the developmental period. The results on host plants, citrus, Ficus nitida and mango showed that the life cycle of A. aurantii, at 30^oC were 49.8±11.31, 68.9±19.30 and 81.3±18.31 days, respectively. These results indicated that A. aurantii prefers citrus followed by Ficus nitida and mango. Twelve species of parasitoids and nine species of predators were collected and recorded, one of them is new record and this is Encarsia lounsburyi (Berlese & Paoli) (Hymenoptera: Aphelinidae).