Fruits, 2009; 64:83-90Introduction. Studies to determine the pre-requisites for formulating an IPM pro- gram for fruit flies (Diptera: Tephritidae) were conducted in the Morogoro region, Central Tanzania, from 2004 to 2006. Specifically, studies aimed at determining the biodiversity of fruit flies, marc.de.meyer@africamuseum.be and their incidence and abundance in the surveyed region. Materials and methods. Adult flies were collected using McPhail traps baited with parapheromones (methyl eugenol, trimedlure 3 and cue lure) and synthetic food baits (hydrolyzed yeast and three-component lure). Flies were also collected from infested fruits after incubation in the laboratory. A total of four sites and neighboring areas representing the three agro-ecological zones of Morogoro region were used. Results. Two key fruit fly pests were determined based on incidence in major fruits and their seasonal abundance. The invasive fruit fly, Bactrocera invadens Drew, Tsuruta and White, is the key pest in the low and medium altitude areas. On the other hand, the Natal fruit fly, Ceratitis rosa Karsch, is the key frugivorous pest in the high altitude areas. Discussion. Management programs of fruit flies need to focus on key pests, taking into consideration their breeding in the non-agricultural habitats. Components of such a program should include the Male Annihi- lation Technique (MAT), legislation, use of parapheromones and baits, farm hygiene and sani- tation, quarantine, surveillance and postharvest treatment.