| Percy Ireland Lathy | |
| Birth Date: | 1874 |
| Birth Place: | Pulborough, West Sussex |
| Death Date: | 8 September 1943 (aged) |
| Death Place: | Vittel, France |
| Nationality: | English |
| Occupation: | Entomologist |
Percy Ireland Lathy (1874 – 8 September 1943) was an English entomologist who specialised in butterflies. He was an acquaintance of James John Joicey and was associated with Joicey's Hill Museum in Witley, Surrey.
Percy Ireland Lathy was born in Pulborough, West Sussex, in 1874. He lived for some time at Tillington.
Lathy was first assistant to William Watkins, in Eastbourne then curator for Herbert Jordan Adams in Enfield (this collection is now in the Natural History Museum, London). At this time, on Adams' behalf, he collected in the West Indies (especially Jamaica) and South America and employed collectors who were sent to Peru and Dutch New Guinea. He also acquired the Honrath and van de Poll collections for Adams. After Adams' death in 1912, he worked for Cabinet Le Moult in Paris then for Aimée Fournier de Horrack. Aimée Fournier de Horrack was a leading figure in literary and musical circles and had a private butterfly collection containing very rare and expensive species of Morpho, Agrias, Catagramma, Prepona, Papilionidae, Ornithoptera, Charaxes, Riodininae and Lycaenidae. The Aimée Fournier collection is now in Muséum national d'histoire naturelle. "L'essentiel des insectes [''[[Parides]]] provient de collections privées comme celle, classée monument historique et riche en papillons exotiques, de Mme Aimée Fournier de Horrack".
Lathy lived for some years in Paris at 90 Boulevard Malesherbes (Aimée Fournier's address) and then at 70, Boulevard Auguste Blanqui and, after 1928, in New York City. He was a specialist in Lepidoptera. Lathy was a member of the Société Entomologique de France (presented by Eugène Le Moult), the Entomological Society of London, the Zoological Society of London and the Entomological Society of America.
After retirement Lathy lived at Gagny in Seine-et-Oise. He died in a German internment camp in Vittel, France, in 1943.
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