This image shows a bee fly cruising about the flowers of an isolated Gilia plant. The bee fly (or single look-alikes) repeatly visited the flowers of this lone Gilia plant every 5 or so minutes for quite a while. My best current guess at the plant species is Gilia scopulorum, but it's not supposed to occur this high...and I find most Gilias very difficult to ID to species! The area was an open Pinyon woodland, with sagebrush (Artemsia nova) and Ephedra the dominant shrubs---occurring in steep, dry, rugged terrain.

Using Cole(1) and Hull(2) this bombyliid keyed to subfamily Usiinae, genus Oligodranes. In those (somewhat outdated) references Oligodranes is distinguished from the genus Apolysis by wing venation (i.e. Oligodranes is taken to have distinct medial and 2nd posterior cells separated by a cross-vein, as opposed to Apolysis which lacks such a cross-vein and instead has a single long cell corresponding to the union of the medial and 2nd posterior cells). However, I believe the taxonomy has been revised, and from Neal Evenhuis's comment here, I'm guessing this bee-fly is currently placed in Apolysis. But I'm not sure...comments welcome and appreciated.

[Update on 8/7/08: Series moved from Usiinae to Apolysis in response to comment by Andy Calderwood.]
[Update on 8/8/08: The plant species ID of Gilia scopulorum was confirmed by Gilia authority J. M. Porter.]