Le Naturaliste

More on Lepidophora
I've found some information on identifying L. lutea and L. lepidocera. From Painter, R.H. and E.M. Painter. 1962. Notes on and redescriptions of types of North American Bombyliidae (Diptera) in European museums. J. Kans. Entomol. Soc. 35: 2-164 comes this quote:

"Three species of this genus have been distinguished in the United States. The Texas species, vetusta Walker, is quite distinct; the eastern forms are less so and may with future study be shown to be subspecies. In the northern form [ie. lutea] the pale scales are mostly yellow and there are abundant yellow scales on the sides of the fourth abdominal segment. In the more southern form [ie. lepidocera] the pale scales are white or pale yellow and usually no pale scales are evident on the fourth abdominal segment."

This paper also gives lutea as a new name for the northern species - both species had been recognized earlier, but lutea had mistakenly been referred to as lepidocera and lepidocera had been referred to as aegeriiformis (but lepidocera has priority).

I suspect that this specimen from Michigan is thus lutea and the other images in the guide from further south are all lepidocera. The other photo of this specimen clearly shows scales on the fourth segment. The southern ones are a bit trickier. They are paler yellow than this specimen, but that could be partly due to differences in the saturation of the photos. Colour differences might also be more dramatic in dried and partially faded museum specimens as well. They all seem to show a lack of scales on the fourth segment though, and since they are present on the other segments this wouldn't be due to wear.
… Joel Kits, 5 March, 2005 - 3:39pm