Evans was the third son of Sir Horace Moule Evans and Elizabeth Anne, daughter of Surgeon General J. T. Tressider. His mother kindled an interest in nature and, when he was sent to King's School, Canterbury, he was already interested in butterflies and moths. He joined the army at the age of 18 and was posted with the Royal Engineers. In 1898 he began collecting butterflies in Chitral. He was sent on duty with the Somaliland Expedition (1902–04), and he injured his knee. He served in France from 1914 to 1918 and was awarded the D.S.O. and a brevet. Exposure to poison gas, however, caused him permanent chest problems. He returned to India in 1919 with his final post in the Western Command at Quetta as a Chief Engineer.[1]
He retired in 1931 and travelled to London via Australia. His home was close to the Natural History Museum and he continued to work on Military service and was attached with the Non-Intervention Committee during the Spanish Civil War and later took up work as an Air Raid Warden. He was at a window in the Natural History Museum, facing South onto Cromwell Road when a German V1 flying bomb burst on the road 100 yards (91 m) away. He was injured and his hearing was permanently impaired.
His wife lived in Bournemouth during the air raids (and died there in 1945). Evans, however, stayed in London to complete his Revision of the Hesperiidae of the world, as he stated "before he died".
Evans collected butterflies throughout his career in India and was very knowledgeable on distribution patterns. His favourite collection areas included Kodaikanal, Jabalpur, Simla, Murree, Darjeeling, Chitral and Baluchistan. He travelled to Australia to collect the endemic subfamily Trapezitinae. He did not set and preserve specimens in cabinets and preferred paper covers.
His only son, Dr. J. W. Evans, continued in Entomology as a Director of the Australian Museum, Sydney. His collection is in the Natural History Museum, London.
1937. A Catalogue of the African Hesperiidae. British Museum (Natural History), London.
1949. A Catalogue of the Hesperiidae From Europe, Asia, and Australia in the British Museum (Natural History).
1951. A Catalogue of the American Hesperiidae Indicating the Classification and Nomenclature Adopted in the British Museum (Natural History). Part I. Pyrrhophyginae. British Museum, London.
1952. A Catalogue of the American Hesperiidae Indicating the Classification and Nomenclature Adopted in the British Museum (Natural History). Part II. Pyrginae. Section I. British Museum, London.
1953. A Catalogue of the American Hesperiidae Indicating the Classification and Nomenclature Adopted in the British Museum (Natural History). Part III. Pyrginae. Section II. British Museum, London.
1955. A Catalogue of the American Hesperiidae Indicating the Classification and Nomenclature Adopted in the British Museum (Natural History). Part IV. Hesperiinae and Megathyminae. British Museum, London.
