G.W. Jeffery donated insects from Barberton to the Transvaal Museum (now the Ditsong National Museum of Natural History), Pretoria, in 1903/4. Many of the specimens proved to be new to the known fauna of the territory. He followed this up with a collection of Lepidoptera, chiefly moths, during 1905/6, and more moths during 1906/7. All the specimens were from the Barberton area. At some time he also donated Lepidoptera to the museum from Kenya.
He was probably George William Jeffery, who lived at Kilifi on the coast of Kenya, and died at Nairobi on 15 January 1952.