Great comments. I had written that guide page for L. lepidocera rather sloppily, not really differentiating among the three species. L. lepidocera appears to be the only species present down here in North Carolina, as it is in Brimley (1), Insects of North Carolina, and on the list from the state at North Carolina State University. However that is not based on keying, just checklists. I probably should have left my images at the genus level.

I see another reference to L. lutea from Quebec. L. lutea might be northern. I can't find anything on the other species, L. vetusta.

Patrick Coin
Durham, North Carolina

This prompted me to do some more digging. Distributions from the World Catalog of Bee Flies (online here, Lepidophora is in part 2):

lepidocera: USA (Florida, Georgia, Iowa, Louisiana, Missouri, Ohio, Oklahoma, South Carolina, Texas)

lutea: Canada (Ontario), USA (Florida, Louisiana, Maine, Minnesota, Missouri, New Jersey, New York, Ohio, Pennsylvania, West Virginia)

vetusta: Nearctic: Mexico (Colima, Guerrero, Nayarit, Sinaloa, Sonora, Veracruz-Llave), USA (Texas). Neotropical: Costa Rica, Guatemala, Mexico (Chiapas, Oaxaca), Nicaragua

Lutea does seem to be somewhat more northern, but clearly there are a lot of states missing, so I'm not sure if it is possible to make an ID on these ranges. Definitely not vetusta, though.

Oh, very interesting--looks like L. lutea is widely distributed as well as is lepidocera. (L. lutea only described in 1962 I see, which means it would not have been in Brimley's 1930's work on Insects in North Carolina, even if the species occurs here.) I'll certainly have to move the images and guide material for L. lepidocera up to the genus level, which is certainly good enough for me in the fly department.

Patrick Coin
Durham, North Carolina

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.