Diptera.info

Posted by runetk on 18-11-2021 17:42

Is it possible to ID this? [My ref: RTK2020-D243B]
Location: North-Norway - Harstad
Habitat: Near the sea. Size: 7.8mm - Date: 14.07.2020 - collected.

Edited by runetk on 19-11-2021 11:13

Posted by runetk on 18-11-2021 21:34

Thanks for the determination Nikita |t,
I checked the Key for Thricops and took some more photos of important sections.
1. Thorax = stripes (indistinct stripes lacking median stripe)
2. arista hair size = with of ant. seg.3
3. abdomen (not complete median stripe)
= T.longipes
Do you agree?

best regards
-Rune

Posted by Nikita Vikhrev on 18-11-2021 22:45

Rune, to differ females is not an easy task.
I did my best here:
https://ia600502.us.archive.org/26/items/RevisionOfTheKeyCharactersForTheThricopsNigrifronsSpecies-group/788-G-3-layout.pdf

Posted by runetk on 19-11-2021 00:20

Your ZooKey was enlightening reading, |t
I used the old key from "E. C. M. D'ASSIS" 1968
So I ended up with the reverse result because of the missprint in the key.
Female scutum in posterior view on my specimen shows (1a) what you describes as a T.nigrifrons.
(no median vitta)
The abdomen and arista characters are unreliable as you describe it. :-)
p 11:Female: Hind tibia t3 with only 2 ad seta (check.. se picture)
p 12: Female dusting on thorax ground color yellow with brown tint (check)

Your (T-nigrifrons species-group) female key:
1-2
2-T.nigrifrons