Schizophora
Encyclopedia
Schizophora is a section of true flies
containing 78 families, which are collectively referred to as muscoids, even though - technically - the term "muscoid" should be limited to flies in the superfamily Muscoidea
; this is an example of informal, historical usage persisting in the vernacular. The section is divided into two subsections, the Acalyptratae
and Calyptratae
, which are commonly referred to as acalyptrate muscoids and calyptrate muscoids, respectively.
The defining feature of the Schizophora is the presence of a special structure that is used to help the emerging adult fly break free of the puparium; this structure is an inflatable membranous sac called the ptilinum
that protrudes from the face, above the antennae
. The inflation of the ptilinum (using fluid hemolymph
rather than air) creates pressure along the line of weakness in the puparium, which then bursts open along the seam to allow the adult to escape. Once the adult emerges, the fluid is withdrawn, the ptilinum collapses, and the membrane retracts entirely back inside the head. The large, inverted "U"-shaped suture in the face through which it came, however, is still quite visible, and it is this ptilinal suture or frontal suture from which the name "Schizophora" ("split-bearers") is derived. The term was first used by Eduard Becher
.
Diptera
Diptera , or true flies, is the order of insects possessing only a single pair of wings on the mesothorax; the metathorax bears a pair of drumstick like structures called the halteres, the remnants of the hind wings. It is a large order, containing an estimated 240,000 species, although under half...
containing 78 families, which are collectively referred to as muscoids, even though - technically - the term "muscoid" should be limited to flies in the superfamily Muscoidea
Muscoidea
Muscoidea is a superfamily of flies in the subsection Calyptratae....
; this is an example of informal, historical usage persisting in the vernacular. The section is divided into two subsections, the Acalyptratae
Acalyptratae
Acalyptratae is a subsection of Schizophora, commonly referred to as the acalyptrate muscoids . It is a very large assemblage, exhibiting very diverse habits, with one notable and perhaps surprising exception; there are no known acalyptrates that are obligate blood-feeders , though this is a life...
and Calyptratae
Calyptratae
Calyptratae is a subsection of Schizophora in the insect order Diptera, commonly referred to as the calyptrate muscoids...
, which are commonly referred to as acalyptrate muscoids and calyptrate muscoids, respectively.
The defining feature of the Schizophora is the presence of a special structure that is used to help the emerging adult fly break free of the puparium; this structure is an inflatable membranous sac called the ptilinum
Ptilinum
The ptilinum is an eversible pouch on the head, above the base of the antenna in schizophoran flies . 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...
that protrudes from the face, above the antennae
Antenna (biology)
Antennae in biology have historically been paired appendages used for sensing in arthropods. More recently, the term has also been applied to cilium structures present in most cell types of eukaryotes....
. The inflation of the ptilinum (using fluid hemolymph
Hemolymph
Hemolymph, or haemolymph, is a fluid in the circulatory system of some arthropods and is analogous to the fluids and cells making up both blood and interstitial fluid in vertebrates such as birds and mammals...
rather than air) creates pressure along the line of weakness in the puparium, which then bursts open along the seam to allow the adult to escape. Once the adult emerges, the fluid is withdrawn, the ptilinum collapses, and the membrane retracts entirely back inside the head. The large, inverted "U"-shaped suture in the face through which it came, however, is still quite visible, and it is this ptilinal suture or frontal suture from which the name "Schizophora" ("split-bearers") is derived. The term was first used by Eduard Becher
Eduard Becher
Eduard Becher was an Austrian entomologist who worked on Diptera. He wrote Zur Kenntnis der Kopfbildung der Dipteren Wien ent. Zeitung, 1: 49-54...
.