The Aphididae, or aphids, is a large family of nearly 4000 small and soft-bodied insects in the superfamily Aphidoidea. More than 25 aphid species have been found in citrus orchards throughout the world, of which some are of economic importance and others probably occur there sporadically. The aphids infesting citrus in the Mediterranean Region reach their maximal numbers in spring, attaining another, lower peak in autumn, and sometimes a third, of minor importance, during summer. Some of the citrus aphids, like Aphis craccivora Koch, A. fabae Scopoli, Macrosiphum euphorbiae (Thomas), and Myzus persicae (Sulzer), never reach high population levels due to the activity of their natural enemies. The others, Aphis gossypii Glover, A. spiraecola Patch, Toxoptera aurantii (Boyer de Fonscolombe) and T. citricida (Kirkaldy), are serious pests, either because they occur in very large numbers or due to their ability to transmit many virus diseases, including citrus tristeza virus (CTV). Their management is mostly by their many natural enemies. These include parasitoids of the subfamily Aphidiinae (Hymenoptera, Braconidae) and many predators of the families Coccinellidae (Coleoptera), Syrphidae (Diptera); Cecidomyiidae, Chamaemyiidae (Diptera); Anthocoridae, Lygaeidae, Miridae, and Nabidae (Hemiptera) and Chrysopidae (Neuroptera).