Ptilinum
The ptilinum is an eversible pouch on the head, above the base of the antenna in schizophoran flies (often called "Cyclorrhapha"). It is used to force off the end of the puparium in order for the fly to emerge, and after this inflation at emergence, the ptilinum collapses back inside the head, marked thereafter only by the ptilinal suture or frontal suture (which defines the aperture through which it everts).
This article is issued from Wikipedia - version of the 3/15/2013. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.