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 attended
Royal Military Academy, Woolwich in 1894 and was commissioned in the army at the age of 20. During his time at the Academy, he injured his knee, which reduced his mobility in later life. Evans was trained at the
Royal School of Military Engineering in Chatham in preparation for joining the Royal Engineers. In 1898 he was posted to India and began collecting butterflies in
Chitral. He was sent on duty with the
Somaliland Expedition (1902–04) and was made an
intelligence officer in August 1903. 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 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. From 1923 he published keys to the identification of Indian butterflies in the
Journal of the Bombay Natural History Society. Evans examined over half a million specimens of
Hesperiidae in the museum. Evans was influenced by the works of
Bernhard Rensch,
Ernst Mayr and
Thomas Huxley, but he was not comfortable with the ideas of
phylogenetic classification. He suffered from ill health in his final years, as an after effect of the poison gas he inhaled in the first world war. A bout of pneumonia in 1952 led to partial heart failure and a subsequent heart attack in 1954. He died of heart failure in his sleep on 13 November 1956. == Publications ==