Recognized as a serious coleopterist, he accepted a post as collector for Frederick DuCane Godman and Osbert Salvin to work on Biologia Centrali-Americana.
Champion left England in February 1879 for Guatemala, where he arrived on 16 March into Puerto San José on the Pacific.
The collections are described in a series of articles he wrote to the Entomologist's Monthly Magazine, plus a route summary in Entomologica News (1907, Vol.
Champion also prepared the Coleoptera sections for publication and wrote the volumes and parts covering the Heteromera, the Elateridae and Dascillidae, the Cassidinae, and the Curculionidae.
Champion's beetle collection, including over 150,000 specimens and a very large number of types, is housed at the Natural History Museum, London.