Interesting about determining sex. I had left this at genus level because I don't know what physical characteristics distinguish the L. annulatus from L. ambiguus or other species in the genus and don't know whether the photos capture the detail required. Most ids. seem to be L. annulatus and many of the pictures are quite similar to these. So I'm thinking this would be an adult male L. annulatus.

There are only two species in that genus. Leucotabanus ambiguus can be eliminated by range, but I would like an expert to tell us that we can eliminate every other genera.

Okay. I understand.