 Graham Rotheray of the Museum of Scotland and Dave Horsfield of Scottish Natural Heritage found the Christii fly under the bark of a decaying aspen tree near Grantown-on-Spey.Since then, it has been found in Norway and two or three more times in the Cairngorms.Rotheray described the Christii fly as "a superb example of a boreal species which has lain undiscovered in Scotland for thousands of years" and "a specialist species which adapted and probably came north with the retreat of the ice".