Closest I can ID is a White lined sphinx but seems all the online images vary from one to another, Very large 4-6 inches long
茜草后紅斜線天蛾 (Hippotion rosetta) Size is 50-55mm in length.
香港蝽類昆蟲圖鑑 A Photographic Guide to Hong Kong True Bugs 1st Editon July 2012 - Vor Yiu & Chiu Ha YIP Page 487
On host redbud.
Un gusano verde en el camino del campo escuela scout meztitla