Diptera.info

Posted by Jan Zwaaneveld on 03-05-2007 21:12

Yesterday I found this one inside our house at Leerdam, Netherlands. It was a big fly (appr. 12-15 mm) and after I caught it to put it outside I managed to take some photos. I'm in doubt whether it is Sarcophagidae or perhaps a Sarcophagidae-looking Tachinid fly. The eyes were not as red as photo 1 suggests, and even less red than in photo 2 (I had to use flash).
Most remarkable was that 'nose', it looked almost like a bat!

Posted by Susan R Walter on 03-05-2007 21:21

Jan

It's a very newly emerged Sarcophagid. The 'bat-nose' is used for cutting/pushing it's way out of the pupal case. It will fall off pretty quickly.

Posted by Jan Zwaaneveld on 03-05-2007 22:05

Thanks Susan, very interesting! I did not know they use a removable nose to work their way out of the pupal case :)

Posted by Tony Irwin on 03-05-2007 22:27

Hi Jan- Susan is not strictly correct when she says the "nose" will fall off - it's actually retractable. All "higher" flies have an inflatable sac - the ptilinum. They fill it with fluid to create a hydraulic ram with which they can push open the puparium to emerge. After emergence, the sac deflates and is retracted into the head. The only sign it was there is the suture above the antennal bases and down the sides of the face - the ptilinal suture. This is true of all the acalyptrates and calyptrates (I think!).