
Belongs within: Platypezoidea.
Contains: Metopininae, Phorinae.
The Phoridae, scuttle flies, are a group of small hump-backed flies of diverse habits. Winged species are readily distinguished by the characteristic venation of their wings, with four or five veins (corresponding to the M and R veins) running obliquely across the main body of the wing. The branches of the R vein are strongly thickened relative to the posterior veins; in Sciadocerinae R4+5 approaches the apex of the wing but in members of the clade Euphorida the R veins are all placed close to the wings base. Classification within the Euphorida remains uncertain; the majority of species have been divided between two subfamilies Metopininae and Phorinae, but the phylogenetic accuracy of this division requires investigation. The Holarctic genus Aenigmatias differs from other phorids in the dorsal position of the anterior thoracic spiracle; males are winged but females are wingless and cockroach-like in appearance (Peterson 1987).
Freak of the week: wingless, legless flies
Published 22 September 2010
I found this while looking up identification info for phorid flies, of which we currently seem to be receiving something of an influx in our samples.

Most of what you see in the lower of the two photoes above are larvae of army ants of the genus Aenictus. The odd one out is the whiter ‘larva’ in the centre—which is not a larva at all, but a fully adult female of the phorid fly Vestigipoda longiseta! (The upper photo shows the same animal in close-up.) This bizarre animal makes its living by imitating its host larvae and being fed by the larvae’s deluded carers. Five species of Vestigipoda have been described to date from Malaysia (Disney et al. 1998; Murayama et al. 2008).

Cases of neoteny, where insects develop full sexual maturity while still ‘larvae’, are not unknown among holometabolous insects. However, Vestigipoda cannot be regarded as neotenous because the female has a fully developed adult head.
So far, Vestigipoda seems to only be known from females. It is possible that males, when found, may turn out to be much more normal phorid flies. The challenge would be recognising them as related to their bizarre females.
Systematics of Phoridae
Characters (from McAlpine 1990): Small humpbacked flies, 1-4 mm long. Ptilinal fissure and lunule absent. Wing rounded at apex, with radiating venation: branches of R strongly thickened and crowded into anterior base, four other weak and peculiarly aligned veins in remainder of wing blade; C ending near middle of anterior margin.
<==Phoridae [Phoromorpha] |--Sciadocerinae [Sciadoceridae]B10 | |--Sciadocera rufomaculataWT11 | |--Sciadophora bostoni McAlpine & Martin 1966P92 | |--Eosciadocera Hong 1981H02 | | `--*E. helodis Hong 1981H02 | |--Archisciada Grimaldi & Cumming 1999GC99 | | `--*A. lebanensis Grimaldi & Cumming 1999GC99 | `--Archiphora Schmitz 1929GC99 | |--A. pria Grimaldi & Cumming 1999GC99 | `--+--*A. patagonica (Schmitz 1929)GC99 | `--A. robusta (Meunier 1917)GC99 `--+--Prioriphora McAlpine & Martin 1966 [Prioriphorinae]GC99 | |--*P. canadambra McAlpine & Martin 1966GC99 | |--P. casei Grimaldi & Cumming 1999GC99 | |--P. intermediaGC99 | |--P. longicostalisGC99 | |--P. luzzii Grimaldi & Cumming 1999GC99 | |--P. polyanka Mostovsky 1996GC99 | `--P. setifemoralisGC99 `--EuphoridaB10 |--MetopininaeB10 |--PhorinaeB10 |--AenigmatiasP87 [incl. PlatyphoraA71; AenigmatiinaeB10] | `--A. eurynotusP87 |--Hypocera [Hypocerinae]B10 | `--H. erhmanniB10 `--Conicera [Conicerinae]B10 |--C. (Conicera) dauciP87 `--C. tibialisB10 Phoridae incertae sedis: Aphiura trevicepsM83 ThaumatoxenaGE05 Euliphora grimaldiiGE05 Cryptopteromyia jeanssoniS94 JohowiaB10 Pseudohypocera kertesziB10 *Macrocerides curtifronsB10 Ceratusa crinicornisB10 ApterophoraB10 Eurycnemis alvarengaiB10 LatiborophagaB10 TrineurocephalaB10 ChaetocnemistopteraB10 Gymnoptera simplexB10 Tapantia bicasaB10 NeopleurophoraB10 EnderleinphoraB10 |--E. fuscohalterata [=Beckerina fuscohalterata]B10 `--E. hansoniB10 Brownphora sinefurca [=Beckerina sinefurca]B10 Chaetaspidia convexifronsB10 Cootiphora angustataB10 PhymatopterellaB10 |--P. luteiclavaB10 `--P. miristigma [=Megaselia miristigma]B10 Calamiscus cryptopalpisB10 AcanthophoridesB10 Brachycephaloptera trichopleuraB10 Neophora frontalisB10 Tabelliphora teretipennaB10 Borgmeieriphora multisetosaB10 Laciniomyia dilataB10 ApodicraniaB10 |--A. molinaiB10 `--A. termitophilaB10 MyriophoraB10 SynclinusaB10 MenozziolaB10 DacnophoraB10 Laishania angustithoraxB10 Paurophora borgmeieriB10 Eremophora hyalinaB10 Platydipteron balliB10 Dinocercus caudatusB10 Styletta croceaB10 DahliphoraB10 AllochaetaB10 Travassophora plaumanniB10 Cyphocephalus cavicepsB10 HomalophoraB10 AdelopteromyiaB10 Apterella molliventrisB10 Zikania schmidtiB10 Placophorina obtectaB10 Holopterina longipalpisB10 |--H. l. longipalpisB10 `--H. l. sedulaB10 ThallopteraB10 VeruanusB10 Microselia texanaP87 TermitoxeniaRD77 [TermitoxeniinaeO98] Plectanocnema Schmitz 1926B96 `--P. nudipes (Becker 1901)B96 WandolleckiaPB27 TermitomyiaRD77 PtochomyiaRD77 Aneurina caliginosa [incl. Phora urbana]RD77 ElectrophoraP92 HypoceriditesP92 ProtophoritesP92 ProtoplatyphoraP92 StephanostoriscusP92
*Type species of generic name indicated
References
[A71] Askew, R. R. 1971. Parasitic Insects. Heinemann Educational Books: London.
[B96] Brown, B. V. 1996. First record of the genus Plectanocnema Schmitz in North America (Diptera: Phoridae). Proceedings of the Entomological Society of Washington 98 (3): 608–609.
[B10] Brown, B. V. 2010. Phoridae (hump-backed flies, scuttle 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. 2 pp. 725–761. NRC Research Press: Ottawa.
Disney, R. H. L., A. Weissflog & U. Maschwitz. 1998. A second species of legless scuttle fly (Diptera: Phoridae) associated with ants (Hymenoptera: Formicidae). Journal of Zoology 246 (3): 269–274.
[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.
[H02] Hong Y. 2002. Amber Insect of China. Beijing Scientific and Technological Publishing House.
[M83] Martin, N. A. 1983. Miscellaneous observations on a pasture fauna: an annotated species list. DSIR Entomology Division Report 3: 1–98.
Maruyama, M., R. H. L. Disney & R. Hashim. 2008. Three new species of legless, wingless scuttle flies (Diptera: Phoridae) associated with army ants (Hymenoptera: Formicidae) in Malaysia. Sociobiology 52 (3): 485–496.
[O98] Oosterbroek, P. 1998. The Families of Diptera of the Malay Archipelago. Brill: Leiden.
[P87] Peterson, B. V. 1987. Phoridae. In: McAlpine, J. F. (ed.) Manual of Nearctic Diptera vol. 2 pp. 689–712. Research Branch, Agriculture Canada.
[PB27] Pilsbry, H. A., & J. Bequaert. 1927. The aquatic mollusks of the Belgian Congo, with a geographical and ecological account of Congo malacology. Bulletin of the American Museum of Natural History 53 (2): 69–602, pls 10–77.
[P92] Poinar, G. O., Jr. 1992. Life in Amber. Stanford University Press: Stanford.
[RD77] Richards, O. W., & R. G. Davies. 1977. Imms’ General Textbook of Entomology 10th ed. vol. 2. Classification and Biology. Chapman and Hall: London.
[S94] Southcott, R. V. 1994. Revision of the larvae of the Microtrombidiinae (Acarina, Microtrombidiidae), with notes on life histories. Zoologica 48 (2): 1–155.
[WT11] Wiegmann, B. M., M. D. Trautwein, I. S. Winkler, N. B. Barr, J.-W. Kim, C. Lambkin, M. A. Bertone, B. K. Cassel, K. M. Bayless, A. M. Heimberg, B. M. Wheeler, K. J. Peterson, T. Pape, B. J. Sinclair, J. H. Skevington, V. Blagoderov, J. Caravas, S. N. Kutty, U. Schmidt-Ott, G. E. Kampmeier, F. C. Thompson, D. A. Grimaldi, A. T. Beckenbach, G. W. Courtney, M. Friedrich, R. Meier & D. K. Yeates. 2011. Episodic radiations in the fly tree of life. Proceedings of the National Academy of Sciences of the USA 108 (14): 5690–5695.