Citrus is one of the oldest and most important perennial fruit crops of the world and has been a crucial cultivar in the development of technology to manage insect pests. Some of the leading breakthroughs include classical biological control, early fumigation practices, establishment of plant quarantine regulations, biological control through natural enemy conservation, and region-wide eradication programs, all which now form part of the arsenal of integrated pest management programs world-wide. Cultivated citrus has a diverse community of herbivores, even in regions far from citrus origins and often with a diverse assemblage of natural enemies. Although management programs for many of pests rely on chemical control, biological control is a central tactic for management of many pests such as California red scale and citrus mealy bug. Many of the present pest management problems around the world are the result of exotic or newly emerging pests, several of which are also disease vectors.