Thread subject: Diptera.info :: Brachycera
Posted by olep on 15-08-2026 10:20
#1
This Brachycera was found in a marshland above the tree line in the Swedish mountains mid July this year.
Is it possible to say what genus it belongs to? - or even species?
I caught two specimens and both of them has a strange "swollen cheek" - Is there an explanation to this? (The specimens have been preserved in alcohol)
Posted by olep on 15-08-2026 10:21
#2
Closer and a bit different light and focus
Edited by olep on 15-08-2026 10:22
Posted by olep on 15-08-2026 10:23
#3
Head above
Edited by olep on 15-08-2026 10:23
Posted by olep on 15-08-2026 10:24
#4
Head under
Edited by olep on 15-08-2026 10:25
Posted by olep on 15-08-2026 10:26
#5
Wing
Posted by jck on 15-08-2026 12:27
#6
The swollen cheek is the ptilinum. The flies expand this to force open the puparium when it is time to emerge. Usually it collapses back into the head but not always and you see flies with strange lumps on their heads. There are videos on YouTube which show the process.
James
Posted by olep on 15-08-2026 16:02
#7
Many thanks James for your explanation.
Do you or anyone else have an idea about the genus of this Brachycera - or even what species it is?
Best Regards Ole
Posted by John Carr on 16-08-2026 20:09
#8
Probably subfamily Coenosiinae: dichoptic male, short anal vein, katepisternal bristles in an equilateral triangle.