Thread subject: Diptera.info :: Lejogaster pupa ?

Posted by atylotus on 25-07-2014 15:42
#1

In the mussel Aa (an eutrophic permanent waterbody), just north of Musselkanaal, province of Groningen, The Netherlands, we’ve found a pupa of a Syrphidae (collected 7.iv. 2014) of which I believe may belong to a Lejogaster species. Unfortunately it was killed during emergence, hence lacking the first thoracic segments and the visible head of the pharate adult.
It has a short siphon, fairly long thoracic spiracles with numerous pores and fine concentric grooves and a pair of remarkably large round spots on the third (?) segment which almost touch each other medially. Also it has a longitudinal row of hairs ventro-laterally on the abdominal segments, but perhaps this also occurs in Anasimyia pupa?
Can anybody confirm my identity? or have any idea about the genus or species name?
In photo's below from top to bottom: habitus in dorsal, lateral and ventral view
Thanks in advance.

Edited by atylotus on 25-07-2014 15:49

Posted by atylotus on 25-07-2014 15:43
#2

and some details of the pupa
upper left : 3rd thoracic segment, dorsal view
lower left : anal segment, lateral view
right: thoracic gill