I was thinking to something like Hyles gallii...
http://arthropa.free.fr/index.php?page=galerie&css=noir&critere=fiche&valeur=hylesgallii&nomjpg=014923
http://www.lepiforum.de/lepiwiki.pl?Hyles_Gallii
Near the footpath, in grassland, larches wood not so far. At about 1930 m.