Posted by smol on 08-04-2026 09:46
#3
Auratus wrote:
Hello Sander, Have a look at the very distinct anal vein. When using Mike's key, i think you went rong at couplet 21.
Hello Jan, always happy to see messages from you. Appreciate for allowing me to practice and you directly pointing to the mistake.
I must admit that have been rushing the ID a bit once I did not understand the term "pennate ciliation" (and tackling this genus for the first time). On the Facebook of Diptera UK, I did find a
reference of these bristles, and they are much more obvious as I expected.
Looking at the out-of-focus abdomen, I am guessing this to be a female. Having another try at this one:
Mike(2017): 3rd antennal segment not elongated; discall cell short; thorax black/grey; acrostichals bristles present + legs black; labellae not as long and slender as in Subgenus Aclonempis; discal cell not abnormal + anal vein clear + thorax stripes on rows of bristles; not R. marginata; anal vein distinctly reaching wing margin; palps weak; halteres pale; hind femora is twisted so the ventral side is slightly angled away from the picture. Though, we can see enough to see short and sparse ventral bristles throughout its length; sternum is not visible. Though the 3rd picture does show long hairs, out of focus, at around the base of the coxa.
Only the sides of the prothoracic sternum: Female hind tibiae without pennate ciliation and wings dark → none matches
Whole of prothoracic sternum haired: Axillary lobe looks to be clouded at the wing margin, though this is difficult to determine. The cloud spots at, for example, the anal vein, does seem to match with illustrations of R. subcinerascens. The other route keys to R. sulcatina, but the wing clouds look different. R. subcinerascens does seem to match better.
Reference:
Wing of R. subcinerascens
I might be making too many logical jumps here. I feel like the level of detail is not enough on the wings. There are also a couple of species not in the key of Mike that have been reported in NL. So I might have a look at those at a later stage.
Edited by smol on 08-04-2026 09:52