Key to species of the genus Cyrtosia known from Iran
1 Mesonotum yellow with three black longitudinal stripes, prescutellar area yellow................ Cyrtosia trivitta sp. nov.
- Mesonotum uniformly and coalesced black on disk, prescutellar area black........................................ 2
2 Frons yellow, at most with small black spot medially......................................................... 3
- Frons mostly black or with broad black stripe medially........................................................ 4
3 Scutellum mostly yellow............................................................. C. meridionalis Rondani
- Scutellum completely matte black................................................ C. persica Gharali & Evenhuis
4 Halter knob with large brown spot dorsally.................................. C. bispermatheca Gharali & Evenhuis,
- Halter knob completely yellow........................................................................... 5
5 Frons almost all black, at most ventral margin narrowly yellow................................................. 6
- Frons yellow with black stripe medially........................................ C. baccadomus Gharali & Evenhuis
6 Scutellum completely black, gray dusted....................................................... C. pusilla Loew
- Scutellum black with yellow along posterior margin................................. C. zieglerii Gharali & Evenhuis