Introduction. Knowledge of tephritid diversity in Senegal was poor before2004, so PIP-COLEACP and CIRAD, in collaboration with Cérès-DPV, carried out, in 2004,trapping for preliminary detection of fruit flies in six orchards in the Niayes zone.Materials and methods. We selected three mixed mango orchards and threehomogeneous mango orchards in this zone. In each orchard, we used three attractants:Terpinyl acetate (Ter), Trimedlure (Tri) and Torula (Tor). Traps were serviced weekly.Results. We captured 77 642 fruit flies in more than 4 months includingmango season; they were represented by 18 identified fly species, including tenCeratitis, six Dacus and two Bactroceraspecies. Two very serious pests were identified with the confirmation ofBactrocera cucurbitae (Coquillett) for cucurbit crops and the detectionof B. invadens Drew Tsuruta & White for fruit crops. The two mostabundant species of Ceratitis were C. cosyra andC. silvestrii. Discussion. We captured more fruit flyspecies in mixed mango orchards than in homogeneous mango orchards. Bactrocerainvadens was also more abundant in mixed orchards, probably because of itspolyphagous status. This new invasive species, B. invadens, can have manyhosts in mixed mango orchards, enhancing its breeding potential. Conclusion.Effective management to deal with this alien species requires: (i) improvement of basicand applied research; (ii) an effective IPM package; (iii) an area-wide managementapproach; (iv) a sub-regional effort on the part of researchers, extension services,growers, exporters, farming associations and the different actors in fruit value chains(mainly mango).