Belongs within: Tabanomorpha.
The Rhagionidae are a group of slender flies, mostly of poorly known habits. Females of some species are blood-suckers but others are reported to be predaceous on other insects. Larvae, where known, are predators of earthworms and insect larvae (Kerr 2009). The classification of the family has been subject to debate with several genera historically included since transferred to other families.
Characters (from James & Turner 1981): Slender flies, 4-15 mm long. Legs usually elongated. Abdomen elongated and conical. Body usually thinly clothed with stiff pile, but rarely with bristles. Color basically drab, but frequently with yellow or orange markings, rarely predominantly so. Head hemispherical, sometimes narrower than thorax. Vertex nearly flush with eyes. Facial area with prominent strongly convex clypeus extending almost to base of antennae and separated from parafacials by deep grooves. Eyes bare, holoptic or narrowly separated in male, widely separated in female; upper ommatidia in male usually enlarged. Antenna variable in form; scape and pedicel usually small, but scape sometimes lengthened, expanded, or densely haired; flagellum with eight tapering flagellomeres, or with an enlarged sometimes pendulous basal flagellomere bearing an apical usually unsegmented stylus or arista. Proboscis usually fleshy, sometimes equipped for sucking blood; palpus well-developed, two-segmented. Thorax of ordinary form; scutellum fairly large, unarmed. Legs simple, never dilated, at most with hind femur somewhat clubbed; hind coxa usually with small tubercle anteriorly; spurs present at apex of at least mid tibia though these are sometimes small, and one or two usually present on hind tibia; fore tarsus frequently with erect tactile hairs below; empodia pulvilliform. Calypter small. Wing always present, elongated; venation strong; C continued around wing as an ambient vein; cell d or dm situated near center of wing, rarely absent; M two- or three-branched; Rs arising far before base of cell d or dm; crossvein r-m usually well before, rarely at, middle of cell d or dm. Abdomen usually with seven segments and portions of terminalia visible, tapered posteriorly; seven pairs of spiracles present. Female terminalia with ovipositor telescopic; cercus two-segmented, with first segment usually expanded ventrolaterally; three round spermathecae. Male terminalia with hypandrium partially or completely distinguishable from bases of gonocoxi; gonostylus simple; parameres forming conical aedeagal sheath; epandrium together with a narrow tergite 10 and cerci not completely covering gonopods. Larva elongated, cylindrical, somewhat maggot-like, tapering anteriorly, more or less truncate and variously lobed posteriorly, consisting of a head and eleven distinct body segments that are never secondarily divided. Head capsule slender, widely open posteroventrally, mostly retracted within thorax; tentorial phragmata and tentorial arms present; no metacephalic rods; mandible slender, curved, blade-like, not provided with a poison canal, articulated to mandibular brush of posteriorly curved spines and to maxilla lying laterally. Body smooth or with hairs and bristles. Creeping welts present ventrally on abdominal segments 1-6 or 1-7. Respiratory system amphipneustic or apneustic; anterior spiracles probably not functional; posterior ones usually functional, located flush with body wall on posterior face of terminal segment. Terminal segment with lobes or tubercles of various form surrounding spiracles; no respiratory tube.
<==Rhagionidae |--Scelorhagio mecomastigus Zhang, Zhang & Li 1993MR03 |--Palaeoarthroteles mesozoicusBLM02 |--Grimmyia balticaGE05 |--ProtobrachyeronGE05 |--Ija problematicaGE05 |--JurabrachyceronGE05 |--Paleobolbomyia sibiricaGC99 |--Mongolomyia latitarsisGE05 |--LeborhagioGE05 |--Atherinomorpha festucaGE05 |--Zarzia zherikhiniGE05 |--PachybatesSt61 |--Arthroceras leptisJT81 |--Palaeohilarimorpha bifurcataW81 |--*Neorhagio setosus [=Leptis setosa]K09 |--Atherimorpha festucaGC99 |--Palaeobrachyceron nagatomiiRJ93 |--Probolbomyia modestaGC99 |--UssatchoviaGC99 |--SolomomyiaGC99 |--StylospaniaGC99 |--DesmomyiaGC99 |--PseudopetiaGC99 |--ProtovermileoP92 |--Succinatherix Stuckenberg 1974P92 |--Mesobolbomyia Grimaldi & Cumming 1999GC99 | `--*M. acrai Grimaldi & Cumming 1999GC99 |--Paleochrysopilus Grimaldi & Cumming 1999GC99 | `--*P. hirsutus Grimaldi & Cumming 1999GC99 |--Jersambromyia Grimaldi & Cumming 1999GC99 | `--*J. borodini Grimaldi & Cumming 1999GC99 |--Austroleptis [Austroleptinae]K09 | `--A. rhyphoidesCM91 |--Simulidium Westwood 1854MR03 | `--*S. priscum Westwood 1854MR03 |--Pseudosimulium Handlirsch 1906MR03 | `--*P. humidum (Brodie 1845) [=Simulium humidum]MR03 |--PaleobrachyceronGE05 | |--P. handlirschiGC99 | `--P. willmanniGE05 |--Heterotropus Loew 1873GC99, H72 | |--H. gilvicornisGC99 | `--H. senexH81 |--PtiolinitesGE05 | |--P. almuthaeGE05 | |--P. cretaceousGE05 | `--P. oudatchinaeGE05 |--Spaniopsis White 1914F15 | |--S. clelandi Ferguson 1915F15 | |--S. longicornis Ferguson 1915F15 | |--S. marginipennis Ferguson 1915F15 | |--S. tabaniformis White 1914F15 | `--S. vexans Ferguson 1915F15 `--Rhagio Fabricius 1775 [=Leptis Fabricius 1805]So61 |--R. atratusL02 |--‘Paleohilarimorpha’ bifurcataGC99 |--R. holosericeus [=Styrex holosericeus]L02 |--R. mystaceusK09 |--R. (Ortochile) nigrocaeruleusG20 |--R. (Pachystomus) syrphoidesG20 |--R. scolopaceaRD77 [=Leptis scolopaceaF15] |--‘Leptis’ strigosaF15 |--R. tringariusL02 |--R. (Rhagio) vermileoG20 [=Leptis vermileoR13] `--R. vertebratusK09
*Type species of generic name indicated
References
[BLM02] Blagoderov, V. A., E. D. Lukashevich & M. B. Mostovski. 2002. Order Diptera Linné, 1758. The true flies (=Muscida Laicharting, 1781). In: Rasnitsyn, A. P., & D. L. J. Quicke (eds) History of Insects pp. 227–240. Kluwer Academic Publishers: Dordrecht.
[CM91] Colless, D. H., & D. K. McAlpine. 1991. Diptera (flies). In: CSIRO. The Insects of Australia: A textbook for students and research workers 2nd ed. vol. 2 pp. 717–786. Melbourne University Press: Carlton (Victoria).
[F15] Ferguson, E. W. 1915. Descriptions of new Australian blood-sucking flies belonging to the family Leptidae. Journal and Proceedings of the Royal Society of New South Wales 69: 233–243.
[G20] Goldfuss, G. A. 1820. Handbuch der Naturgeschichte vol. 3. Handbuch der Zoologie pt 1. Johann Leonhard Schrag: Nürnberg.
[GC99] Grimaldi, D., & J. Cumming. 1999. Brachyceran Diptera in Cretaceous ambers and Mesozoic diversification of the Eremoneura. Bulletin of the American Museum of Natural History 239: 1–124.
[GE05] Grimaldi, D., & M. S. Engel. 2005. Evolution of the Insects. Cambridge University Press: New York.
[H72] Hall, J. C. 1972. New North American Heterotropinae (Diptera: Bombyliidae). Pan-Pacific Entomologist 48 (1): 37–50.
[H81] Hall, J. C. 1981. Bombyliidae. In: McAlpine, J. F., B. V. Peterson, G. E. Shewell, H. J. Teskey, J. R. Vockeroth & D. S. Wood (eds) Manual of Nearctic Diptera vol. 1 pp. 589–602. Research Branch, Agriculture Canada.
[JT81] James, M. T., & W. J. Turner. 1981. Rhagionidae. In: McAlpine, J. F., B. V. Peterson, G. E. Shewell, H. J. Teskey, J. R. Vockeroth & D. S. Wood (eds) Manual of Nearctic Diptera vol. 1 pp. 483–488. Research Branch, Agriculture Canada.
[K09] Kerr, P. H. 2009. Rhagionidae (snipe flies). In: Brown, B. V., A. Borkent, J. M. Cumming, D. M. Wood, N. E. Woodley & M. A. Zumbado (eds) Manual of Central American Diptera vol. 1 pp. 485–489. NRC Research Press: Ottawa.
[L02] Latreille, P. A. 1802. Histoire Naturelle, générale et particulière des crustacés et des insectes vol. 3. Familles naturelles des genres. F. Dufart: Paris.
[MR03] Mostovski, M. B., A. J. Ross, R. Szadziewski & W. Krzeminski. 2003. Redescription of Simulidium priscum Westwood and Pseudosimulium humidum (Brodie) (Insecta: Diptera: Rhagionidae) from the Purbeck Limestone Group (Lower Cretaceous) of England. Journal of Systematic Palaeontology 1 (1): 59–64.
[P92] Poinar, G. O., Jr. 1992. Life in Amber. Stanford University Press: Stanford.
[R13] Reuter, O. M. 1913. Lebensgewohnheiten und Instinkte der Insekten bis zum Erwachen der sozialen Instinkte. R. Friedländer & Sohn: Berlin.
[RD77] Richards, O. W., & R. G. Davies. 1977. Imms’ General Textbook of Entomology 10th ed. vol. 2. Classification and Biology. Chapman and Hall: London.
[RJ93] Ross, A. J., & E. A. Jarzembowski. 1993. Arthropoda (Hexapoda; Insecta). In: Benton, M. J. (ed.) The Fossil Record 2 pp. 363–426. Chapman & Hall: London.
[So61] Southcott, R. V. 1961. Studies on the systematics and biology of the Erythraeoidea (Acarina), with a critical revision of the genera and subfamilies. Australian Journal of Zoology 9: 367–610.
[St61] Stuckenberg, R. R. 1961. Diptera (Nematocera): Thaumaleidae. In: Hanström, B., P. Brinck & G. Rudebeck (eds) South African Animal Life: Results of the Lund University Expedition in 1950–1951 vol. 8 pp. 409–412. Almqvist & Wiksell: Uppsala.
[W81] Webb, D. W. 1981. Hilarimorphidae. In: McAlpine, J. F., B. V. Peterson, G. E. Shewell, H. J. Teskey, J. R. Vockeroth & D. S. Wood (eds) Manual of Nearctic Diptera vol. 1 pp. 603–605. Research Branch, Agriculture Canada.