He was the first to discover the life cycle of the large copper butterfly (Lycaena dispar) and succeeded in establishing a colony of L. d. rutilus at his home in Greenfields, Tipperary.
He also discovered the life history of the large blue butterfly (Phengaris arion) whose larvae live in the nest of the ant Myrmica sabuleti.
Purefoy was born on the Greenfields estate, Tipperary, in a landed Irish family, the second son of Captain (Honorary Colonel) Edward Bagwell-Purefoy (1819-1883) and Charlotte Wilkinson.
He became a fellow of the Royal Entomological Society and between 1915 and 1926 he was successful in reintroducing a population of the large copper butterfly which had gone extinct in Britain around 1850.
[3][4] He also identified the association of an ant species in the life cycle of the large blue butterfly which became extinct in the UK after his death.