If this is D. brevis I'm baffled as to where it should be placed in terms of subspecies. Something significant like a white lower frons, mandibles, and almost entirely white clypeus is usually something you'd mention in a species description. I've not seen a specimen of Dipogon (Winnemanella) fulleri, but if it's not that this might not even be D. brevis. If someone knows where I could get the literature for that subgenus (Winnemanella) PLEASE let me know. I've never seen this coloration in Dipogon...it's possible this is something significant. It's also possible it's not.