Pallopteridae

Palloptera umbellatarum, copyright Donald Hobern.

Belongs within: Schizophora.

The Pallopteridae, flutter flies, are a group of medium-sized flies whose larvae (where known) are found within flower head and stems and under bark of plants, at least some being predators of burrowing insect larvae (McAlpine 1987).

Characters (from McAlpine 1987): Medium-sized flies, 3-5 mm long, grayish or yellowish, usually with brownish-marked wings and simple legs. Head scarcely as broad as thorax, usually higher than long. Frons broader than high, usually of same width in both sexes, always yellowish at least on anterior half; interfrontal area finely setulose or bare; orbital plate usually weakly differentiated, reaching only slightly below level of anterior ocellus; a single reclinate or lateroreclinate orbital bristle present; ocellar and inner and outer vertical bristles strong; postocellar bristles present but weaker, slightly divergent; lunule linear, unexposed, without setulae. Face somewhat sunken, gently convex, always yellowish, usually with a weak median carina, without hairs or bristles; parafacial linear to moderately broad, without hairs or bristles. Clypeus moderately large; oral vibrissae absent; cheek almost linear to about half height of eye in width; series of fine subvibrissal setulae present, among which are two outstanding distantly separated genal bristles. Compound eye usually nearly round, bare, unpatterned. Antenna short; scape very short, with few fine setulae; pedicel notched on apicodorsal margin, with one bristle and a row of fine setulae along apical margins; first flagellomere usually slightly longer than broad; arista almost bare to shortly plumose. Proboscis short, with well-developed labella; palpus usually moderately large, rarely strongly enlarged. Thorax blackish to yellowish in background color, usually pruinose, sometimes polished, occasionally patterned in black and yellow, with yellowish or blackish setulae or bristles or some combination of them. Scutum moderately strongly arched; scutellum usually with convex disc; prescutellum undeveloped; subscutellum moderately well-developed. Prosternum rather narrow, free from proepisternum. Chaetotaxy one of postpronotal and one presutural intra-alar bristle, one presutural and three postsutural dorsocentral bristles, one or two prescutellar acrostichal and two supra-alar bristles, one postsutural intra-alar bristle, one lateral and one subapical scutellar bristle, and two notopleural bristles present; one strong to weakproepisternal bristle present; one weak proepimeral bristle present or absent; anepisternum setulose or bare, with or without one or more strong bristles posteriorly; katepisternum with one bristle and numerous setulae; anepimeron bare; prosternum usually with a few fine setulae; metasternal area bare. Wing moderately long, usually rather narrow but with well-developed anal angle and alula, and variously patterned with brown spots to almost entirely hyaline; cell sc always darkened. C with costagial, humeral, and subcostal weakenings or breaks, and ending rather abruptly just beyond insertion of R₄₊₅; Sc complete; base of R bare, with R₁ ending well beyond insertion of Sc but far before middle of wing; cells bm and dm present and separated by crossvein bm-cu; crossvein r-m joining cell dm at or near midpoint; crossvein dm-cu nearly parallel to crossvein r-m, always closer than its own length to wing margin; cell cup convexly closed; A₁ reaching or nearly reaching wing margin at least as a fold. Alula large. Upper calypter moderately large, with fringe of longish silky hairs; lower calypter linear. Halter entirely whitish. Legs fairly slender. Fore femur with a row of posterodorsal and posteroventral bristles; mid femur usually with one preapical dorsal, one or two anterodorsal, and one anteroventral bristle. Tibiae usually yellowish, usually without preapical dorsal bristles; mid tibia with a fairly strong apicoventral bristle. Tarsi slender, frequently mainly yellowish. Abdomen subcylindrical, dark brown to yellow, seldom patterned. Male usually with five pairs of spiracles in membrane (six pairs in Eurygnathomyia). Tergite 6 usually absent; sternite 6 asymmetric, shifted into left side of abdomen. Syntergosternite 7+8 large, setulose dorsally. Epandrium large, with rather globose sides. Surstylus often absent or indistinguishably fused with lateral margins of epandrium, occasionally well-developed. Hypandrium small, with large median hypandrial apodeme; gonopod small, finely setulose, weakly sclerotized and lobe-like or divided and complex; paramere usually extremely reduced and finely setulose, rarely absent or strongly developed; aedeagus long, finely to coarsely setulose or almost bare, frequently with an enlarged complicated apical glans; epiphallus absent or present; aedeagal apodeme rod-like; ejaculatory apodeme heavily sclerotised, usually rather large. Sternite 10 sometimes with paired stout spines at anterior margin. Cerci small and lobelike or large and elongate. Female with sternite 7 and tergite 7 fused laterally to form stout oviscape and enclosing seventh pair of abdominal spiracles. Ovipositor shaft-like, with cerci fused to form apical point. Two or three sclerotized spermathecae present. Larva with cephalopharyngeal skeleton consisting of paired simple mandibles and dental sclerites, parastomal bars, and a hypopharyngeal sclerite that is clearly separated from pale tentoropharyngeal sclerite. Anterior spiracles fan-shaped, each with five or six papillae. Creeping spines present only anteroventrally on seven or eight abdominal segments. Terminal abdominal segment bluntly rounded posteriorly, without tubercles, but with stump-like projections bearing spiracles.

<==Pallopteridae M87
    |  i. s.: Hypsomyia goilala O98
    |--Eurygnathomyia [Eurygnathomyiinae] M87
    |    `--E. bicolor M87
    `--Pallopterinae M87
         |--Temnosira subarcuata M87
         |--Neomaorina M87
         |--Glaesolonchaea electrica M87
         |--Toxoneura superba M87
         |--Sciochthis M87
         |--Aenigmatomyia M87
         |--Heloparia M87
         |--Homaroides M87
         |--Pseudopyrgota M87
         |--Pallopterites electrica M87
         |--Morgea M87
         |    |--M. freidbergi P92
         |    `--M. mcalpinei M87
         `--Palloptera M87
              |--P. claripennis M87
              |--P. scutellata M87
              |--P. superba M81
              `--P. umbellatarum WT11

*Type species of generic name indicated

REFERENCES

[M81] McAlpine, J. F. 1981. Key to families—adults. 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. 89–124. Research Branch, Agriculture Canada.

[M87] McAlpine, J. F. 1987. Pallopteridae. In: McAlpine, J. F. (ed.) Manual of Nearctic Diptera vol. 2 pp. 839–843. Research Branch, Agriculture Canada.

[O98] Oosterbroek, P. 1998. The Families of Diptera of the Malay Archipelago. Brill: Leiden.

[P92] Poinar, G. O., Jr. 1992. Life in Amber. Stanford University Press: Stanford.

[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.