Contribution a l etude des tiques du Senegal (Acarina, Ixodoidea). 1. Les larves d Amblyomma Koch et de Hyalomma Koch. - The descriptions of the larvae of the senegalese Amblyonuna and Hyalomma are given and their known hosts are listed. The larvae of Hyalomma impressum Koch, 1844 and H. truncatum Koch, 1844 are described for the first time; the descriptions of the larvae of Amblyomma nuttalli Donitz, 1909, A. sparsum Neumann, 1899, A. variegatum (FABRICIUS, 1794), H. dromedarii Koch, 1844, H. impeltatum Schulze and Schlottke, 1930 and H. rufipes Koch, 1844 are brought up to date. Keys for the determination of these larvae are given.