Lauxaniidae key

I don't have a copy of Mark Mitchell's key, but there is a key available as part of Mike's Insect Keys. I haven't used that one myself but it has some illustrations.

Thanks Martin. I've been using the key by Mike Hackston. It's worked well before on at least one other Calliopum, but I'm not convinced with this specimen.

Thanks to those who have helped out with this, including those that contacted me directly.

I've now taken another look at the specimen and am still unable to confidently identify it. I'm now confident that it is a female, but it has a sabre-like ventral projection to the terminalia. Significantly, it has completely black antennae, femora (aside from some yellowing at the knees) and tibiae. It also has 6 rows of acrostichals - whilst I gather this is not fool-proof, I've compared the specimen with another Calliopum collected from the same site that I identified as elisae and the terminalia are distinctly different.

Next awkward request: does anyone have a copy of Semelbauer, M., Dvořáková, K. & Kočišek, J. Comparative morphology of female terminalia of Calliopum Strand, 1928, Lauxania Latreille, 1804 (Diptera, Lauxaniidae) and allies. Biologia 76, 3355–3369 (2021). https://doi.org/10.1007/s11756-021-00825-7? I wonder if this might shed some light.