Introduction. Losses in West African commercialmango orchards due to fruit fly infestations have exceeded 50% bythe middle of the crop season since 2005, resulting in considerableincome loss for the growers. Materials and methods.In 2009, weekly monitoring of adult fruit fly species of economicsignificance was carried out in eight West African countries at12 sites across five agro-ecological zones: (i) Humid Forest, (ii)Guinean savanna, (iii) Southern Sudan, (iv) Northern Sudan, and (v)Sahelian. Trapping was performed using methyl eugenol and terpinylacetate in 288 Tephri-traps, targeting Bactrocera invadens and Ceratitis cosyra. Results. The datashowed that B. invadens was present throughoutthe year in the Forest zone, abundant for 7 months, with a peakin May at the end of the mango season, C. cosyra beingtotally absent. In the Guinean savanna zone, B. invadens wasabundant for 6-7 months, with a peak at the beginning of June coincidingwith the season, with a few C. cosyra. In the SouthernSudan zone, B. invadens was abundant for 6 months, witha peak in mid-June during the season, C. cosyra peakingin April. In the Northern Sudan zone, B. invadens wasabundant for 5 months, with a peak at the end of June at the endof the season, C. cosyra peaking in May. In theSahelian zone, B. invadens was abundant for 4 months,peaking in August during the season, C. cosyra peakingjust before. These preliminary results showed that the exotic species, B. invadens, was present at high levels [mean peakof 378 flies per trap per day (FTD)] in all agro-ecological zones, whilethe native species, C. cosyra, preferred the drierzones of West Africa, with lower population levels (mean peak of 77 FTD). Conclusion. Detection trapping of male flies with parapheromonesis a useful indicator of field population levels and could be usedto deploy control measures (IPM package) in a timely manner whenthe Economic Injury Level is reached. Control strategies for thesequarantine mango fruit fly species are discussed with respect toagro-ecological zones and the phenological stages of the mango tree.