Hallo Stéphane: It can be Gymnetis chalcipes Gory & Percheron, 1833, but he can also be Gymnetis lanius Linnaeus, 1766. Then can you show a photo in lateral view ? (I need to see prosternal process) and also I would like to know the color of the hairs of the posterior tibia?, normally in G. lanius these hairs are red and G. chalcipes are black (I can not see either of these in your photo).
Saludos,
Carlos