--Introduction. Knowledge of tephritid diversity in Senegal was poor before 2004, 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 three homogeneous 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 including mango season; they were represented by 18 identified fly species, including ten Ceratitis, six Dacus and two Bactrocera species. Two very serious pests were identified with the confirmation of Bactrocera cucurbitae (Coquillett) for cucurbit crops and the detection of B. invadens Drew Tsuruta & White for fruit crops. The two most abundant species of Ceratitis were C. cosyra and C. silvestrii. Discussion. We captured more fruit fly species in mixed mango orchards than in homogeneous mango orchards. Bactrocera invadens was also more abundant in mixed orchards, probably because of its polyphagous status. This new invasive species, B. invadens, can have many hosts in mixed mango orchards, enhancing its breeding potential. Conclusion. Effective management to deal with this alien species requires: (i) improvement of basic and applied research; (ii) an effective IPM package; (iii) an area-wide management approach; (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). invadens, peut se développer au niveau de nombreuses autres espèces fruitières autres que le manguier, ce qui lui permet d'accroître ses potentialités de reproduction. Conclusion. Une lutte efficace contre cette espèce invasive requiert (i) l'approfondissement de recherches fondamentales et une recherche appliquée efficace, (ii) un paquet technologique efficace en lutte intégrée, (iii) une lutte menée à l'échelle du bassin de production, (iv) un effort général mené à la fois par les centres nationaux de recherche, les services du développement, les exportateurs, les associations de planteurs et les différents intervenants au niveau des filières fruitières (principalement mangue). Senegal / Mangifera indica

The yields of Italian and hybrid ryegrass cvs Promenade and Inca respectively and of tall fescue cv. Pastelle were decreased by M. naasi for the three first months of their growth. The second stage juvenile populations within the roots during establishment were responsible in 1984 for losses of seedlings of Inca and Promenade. Negative correlations were statistically significant between these root populations and the height of both varieties, but dry and fresh plant weight was diminished only in cv. Promenade. The initial population in the soil (Pi) was significantly negatively correlated with dry weights of the plants of all three cultivars after three months growth. At the time of the second yield assessment cvs Inca and Pastelle were tolerant to M. naasi, by contrast with cv. Promenade. The study of the relationships relating to Pi and the root populations of the nematode revealed that J2 invaded the roots of grasses independently of the Pi, but three months after sowing, the number invading was proportional to the Pi. The increase of J2 populations in the roots may have been the consequence of invasion throughout the experiment only at the highest levels of infestation. The development of J2 into females in cvs Inca and Pastelle was negatively related with infestation level, but was independent of Pi in cv. Promenade.