A large multi-institutional, interagency classical biological control program was initiated in the early 1990s to combat the invasion of the B biotype of Bemisia tabaci into the USA. This large program was successful in the discovery, importation, rearing and release of more than 30 species/strains of aphelinid parasitoids (primarily Eretmocerus and Encarsia) from around the world into multiple states. Establishment of several species in each targeted state has been documented. In Arizona two exotic species have become established (Eretmocerus nr. emiratus and Encarsia sophia) and have largely displaced native aphelinid species attacking B. tabaci. However, the impact of these establishments and the overall biological control program in Arizona and elsewhere has been poorly documented. From 1996 through the present in situ life tables have been constructed for B. tabaci on cotton in central Arizona. Analyses of these life tables demonstrate that parasitism varied across years at low to moderate levels but that there is no trend for increasing levels of parasitism since the exotics became established. Additional analyses showed that the irreplaceable mortality supplied by parasitism has not consistently increased since establishment and that parasitism has no explanatory value in predicting total generational mortality. Predation by sucking predators has consistently been the largest source of mortality, has consistently contributed the largest amount of irreplaceable mortality and represents the key-factor explaining variations in total mortality both before and after the establishment of exotic aphelinids.