Schizophora

Definition

A section of the order Diptera (true flies) comprising approximately 78 families, defined by the presence of a ptilinum—a temporary, eversible sac on the head that adult flies use to emerge from the puparium by inflating it with hemolymph pressure. The section encompasses the vast majority of fly diversity and is divided into two subsections: Acalyptratae (acalyptrate muscoids, generally smaller flies with reduced or absent calypters) and Calyptratae (calyptrate muscoids, including blow flies, house flies, and tachinid flies, with well-developed calypters that cover the halteres). The name derives from the ptilinum's split (schizo-) appearance after emergence, leaving a permanent ptilinal suture on the face.

Etymology

Greek schizein (to split, cleave) + -phora (bearing, from Greek pherein, to carry), referring to the ptilinum that splits open or appears cleft after emergence

Example

A forensic entomologist examining a blow fly (family Calliphoridae, subsection Calyptratae) can confirm its placement in Schizophora by locating the ptilinal suture—a distinct, inverted U-shaped groove running from the base of the antennae to the oral margin—evidence of the ptilinum used during eclosion.

Synonyms

• muscoids (informal, imprecise)

Related Terms

• Acalyptratae
• Calyptratae
• Ptilinum
• Diptera
• Brachycera
• calypter
• ptilinal suture
• Eclosion
• Puparium

Usage Notes

The informal term 'muscoid' is often applied loosely to all Schizophora, but technically refers only to the superfamily Muscoidea within Calyptratae. Schizophora excludes the lower Diptera (Nematocera) and the more basal Brachycera such as horse flies and soldier flies (Tabanomorpha, Stratiomyomorpha). The ptilinum and resulting ptilinal suture are diagnostic; their presence distinguishes Schizophora from all other flies. The two subsections differ ecologically: Acalyptratae dominate in decaying vegetation, fungi, and leaf litter, while Calyptratae are prominent in carrion, dung, and parasitoid guilds. When encountering the name in paleontology or microbiology, verify context—unrelated foraminifera and fungi bear the same genus name.