Scatella (Scatella) Robineau-Desvoidy, 1830

Costa, Daniel N. R., Mathis, Wayne N., Marinoni, Luciane & Sepúlveda, Tatiana A., 2024, Phylogeny and taxonomy of the shore-fly tribe Scatellini (Diptera: Ephydridae: Ephydrinae), Zoologia (e 23100) 41, pp. 1-35 : 21-22

Scatella (Scatella) Robineau-Desvoidy, 1830

Figs 6–8 , 15 , 27–30, 46 , 58–62

Scatella Robineau-Desvoidy 1830: 801 (as a genus; feminine). Type species: Scatella buccata Robineau-Desvoidy 1830 (= Ephydra stagnalis Fallén 1813 ), designated by Coquillett 1910: 603. – Mathis and Zatwarnicki 1995: 270–279 [world catalog]. –Zhang and Yang 2005: 1–11 [review, Chinese fauna].

Neoscatella Malloch 1933: 9 (as a genus; feminine). Type species: Neoscatella atra Malloch 1933 , original designation. – Sturtevant and Wheeler 1954: 178 [as a subgenus]. – Beardsley 1991: 142–145 [parasite of a Hawaiian species ( Eucoilidae )]. syn. nov.

Strandella Duda 1942: 30 (as a subgenus of Scatella ; feminine). Type species: Scatella silacea Loew 1860 , original designation. – Dahl 1959: 119 [synonymy].

Trixostomus Rondani 1856: 130 (as a genus; masculine). Type species: Ephydra stagnalis Fallén 1813 , original designation. –Beck- er 1905: 210 [synonymy].

Diagnosis. Scatella (Scatella) is distinguished from other subgenera of the genus Scatella mainly by the presence of white spots in the wing. Other characters useful to differentiate species of Scatella include the following: facial setae conspicuous, 1–2 lateral facial setae curved laterodorsally; wings lightly to darkly infuscate with few to several white spots; row of acrostichal setae not extending to scutellum; sutural acrostichal setae usually longer than other acrostichal setae (if absent, presutural dorsocentral seta present).

Description. Minute to medium-sized shore flies, body length 1.00–3.00 mm; blackish brown to cinereous species, rarely yellow; species macropterous or with wings reduced.

Head ( Figs 15 , 58, 59 ): Frons dull usually with distinct, subshiny to shiny frontal vitta; lateroclinate fronto-orbital seta 2 rarely 3. Antenna short, dark; pedicel setae typical; basal flagellomere round; arista macropubescent to at most bearing short, dorsal, hair-like branches. Face conspicuously protruding, with an interfoveal, dorsal hump, uniformly sclerotized, no processes; facial setae conspicuous, 2–3 lateral facial setae curved laterodorsally or ventrally curved, indistinctly from medial facial setae; small to long ventroclinate setae along oral margin. Eye usually nearly round. Gena short to moderately high, usually bearing a large seta.

Thorax ( Figs 6, 7 , 60 ): Mesonotum generally dark colored, microtomentose, density of tomentum varying, generally unicolorous or with longitudinal stripes, not conspicuously multicolored with pattern of bands and/or spots; dorsocentral setae 2 (0+2), or 3 (1+2); scutellum flat, disc bare, bearing 2 pairs of marginal setae; basal scutellar setae smaller than apical setae; pleural region generally gray, lighter than mesonotum; legs typical, usually without distinct setae (forefemur sometimes with a row of short, stout setae anteroventrally in some species); color of tarsi variable; tarsal claws conspicuously curved and puvilli present below each claw; stem of halter short, head oval, white. Wing generally palely to conspicuously infuscate with white spots, especially in cells r 2+3, r 4+5, and dm but exceptionally in cell r 1 and m 4; costa long, extended to vein M 1, sometimes bearing spines; wing reduced, usually stenopterous in a few species.

Abdomen: Tergites gray to brown, microtomentose, sometimes with lighter posterior margins, or mostly shiny, blackish brown. Male terminalia ( Figs 61, 62 ): sternites 5 and 6 well developed, very small or absent. Epandrium and internal structures typical of Scatella ; ventral projections of epandrium separated or indistinguishable; phallapodeme absent; ejaculatory apodeme present, L shaped, dorsoventrally. Female terminalia ( Figs 8 , 27–30, 46 ): sternite 7 as one rectangular sclerite or 2 lateral, small, circular to partially quadrate sclerites; sternite 8 divided, as 2 lateral, lunate sclerites; female cerci bearing one strong, prominent seta, inserted posteroventrally. Female ventral receptacle tubular shaped, one to five times longer than wide. Species moved from Neoscatella Malloch as new combinations: S. (S.) albilutea Mathis and Wirth, 1981 ; S. (S.) amnica ( Tenorio, 1980) , S. (S.) atra ( Malloch, 1933) ; S. (S.) aurulenta Giordani Soika, 1956 ; S. (S.) austrina Mathis & Wirth, 1981 ; S. (S.) bicolor Mathis & Wirth, 1981 ; S. (S.) bryani Cresson, 1926 ; S. (S.) cilipes ( Wirth, 1948) ; S. (S.) clavipes ( Wirth, 1948) ; S. (S.) crassicosta Becker, 1896 ; S. (S.) curtipennis ( Becker, 1905) ; S. (S.) fluvialis ( Tenorio, 1980) ; S. (S.) furens Cresson, 1931 ; S. (S.) gestiens Cresson, 1931 ; S. (S.) gregaria Cresson, 1931 ; S. (S.) hawaiiensis Grimshaw, 1901 ; S. (S.) ignara Cresson, 1931 ; S. (S.) immaculata Malloch, 1925 ; S. (S.) insularis Mathis and Wirth, 1981 ; S. (S.) karakensis Stuke, 2012 ; S. (S.) kauaiensis ( Wirth, 1948) ; S. (S.) megastoma (Zetterstedt, 1855) ; S. (S.) nelsoni Tonnoir & Malloch, 1926 ; S. (S.) norrisi Mathis & Wirth, 1981 ; S. (S.) oahuense Williams, 1938 ; S. (S.) obscuriceps Cresson, 1915 ; S. (S.) praia Mathis, Marinoni & Costa, 2014 ; S. (S.) setosa Coquillett, 1900 ; S. (S.) sexnotata Cresson, 1926 ; S. (S.) silacea Loew, 1860 ; S. (S.) stuckenbergi ( Wirth, 1956) ; S. (S.) subguttata ( Meigen, 1830) ; S. (S.) tasmaniae Mathis & Wirth, 1981 ; S. (S.) terryi Cresson, 1926 ; S. (S.) victoria ( Cresson, 1935) ; S. (S.) vittithorax Malloch, 1925 ; S. (S.) warreni Cresson, 1926 .

Distribution. Widespread: Afrotropical ( Ethiopia to Cape), Australasian/Oceanian, Nearctic, Neotropical (especially Andean), Oriental, Palearctic Regions.

Remarks. This subgenus comprises 116 species from all tropical and temperate biogeographic regions and is the most speciose taxon in the tribe and subfamily. Most species occur in the Australasian/Oceanic and Neotropical Regions ( Mathis and Zatwarnicki 1995). The species occur in typical habitats to the tribe, such as marshes, mangroves, intertidal areas, dunes and sandy beaches, rocky coasts, muddy and sandy areas along riverbanks and lakes, with emphasis on the species that occur in alkaline or acid hot springs ( Wirth and Mathis 1979). Sixteen species have some immature stage described (see Williams 1938, Tenorio 1980 for the main examples). Scatella stagnalis is found in greenhouses and is the vector of a root disease caused by a Pythium fungus to crops in hydroponic cultures ( Goldberg and Stanghellini 1990). Nine species with reduced wings are known, three from New Zealand and six from Neotropical Region ( Mathis 1980, Harrison 1964, 1976, Wirth 1955).

The species that were formally classified in Neoscatella are interspersed with those of this subgenus, and lacking evidence of monophyly, we have elected to recognize a single subgenus; thus, the synonymy of Neoscatella with Scatella .

Figures

Figures 3–9. (3)Scatella (Teichomyza) fusca, head anterior; (4) Scatella (Synsoplos) sturdeeanus, head lateral; (5)Lamproscatella cephalotes, head dorsal; (6–8) Scatella (Scatella) stagnalis, thorax lateral; (7) thorax dorsal; (8) female, abdomen lateral; (9) Haloscatella arichaeta, thorax dorsal. Abbreviations: anepst, anepisternum; ar, arista; d ped s, dorsal pedicel seta; dc s, dorsocentral seta; fr-orb s, fronto-orbital seta; fr vit, frontal vitta; gn s, genal seta; ial s, intra-alar seta; kepst, katepisternum; npl s, notopleural seta; p spal s, posterior supra-alar seta; pprn lb, postpronotal lobe; prepst, proepisternum; presut acr s, presutural acrostichal seta;presut spal s, presutural supra-alar seta;sctl, scutellum; spal s,supra-alar seta;sctl s,scutellar seta.

Figures 10–23. Head, wing and legs characters: (10) Limnellia sp., head anterior; (11) Scatella (Scatella) sp., head anteri- or; (12) Scatella (Parascatella) sp., head anterior; (13) Hyadina sp., head lateral; (14) Scatella (Parascatella) pilifera, head anterior; (15) Scatella (Scatella) stagnalis, mouth parts; (16) Philotelma sp., head lateral; (17) Physemops nemorosus, head anterior; (18)Ephydra riparia, mouth parts; (19) Scatophila caviceps, wing; (20) Scatella (Scatella) stagnalis, wing; 21, Dagus rostratus, wing; (22) Scatophila mesogramma, male, mid femur posteroventral; (23) Scatella (Scatella) stagnalis, male, fore femur anteroventral.

Figures 24–47.Abdominal sternites and terminalia: (24)Philotelma sp.,female; (25)Philotelma sp.,male;(26)Ephydra (Ephydra) riparia, female; (27) Scatella (Scatella) stagnalis, female; (28) Scatella (Scatella) tenuicosta, female; 29, Scatella (Scatella) tenuicosta, male; (30) Scatella (Scatella) paludum, male; (31) Lamproscatella sibilans, epandrium and cerci, posterior; (32) Haloscatella arichaeta, epandrium andcerci,posterior;(33)Haloscatella karekare,epandrium and cerci,posterior;(34)Hyadina sp., aedeagus lateral;(35)Parydra aquila, aedeaguslateral;(36)Thinoscatella lattini, internal structures ofmaleterminalia (aedeagus[shaded], phallapodeme, gonite+hypandrium), lateral; (37) Diedrops steineri, aedeagus, lateral; (38)Lamproscatella sibilans, internal structures of maleterminalia (aedeagus [shaded],phallapodeme,gonite+hypandrium),ventral;(39)Lamproscatella sibilans, internal structuresof maleterminalia(aedeagus[shaded],phallapodeme,gonite+hypandrium), lateral;(40)Haloscatella arichaeta epandrium and cerci, lateral; (41) Haloscatella arichaeta, internal structures of male terminalia (aedeagus [shaded], phallapodeme, gonite+hypandrium),lateral;(42)Haloscatellakarekare,internal structures of maleterminalia (aedeagus[shaded],phallapodeme, gonite+hypandrium), ventral; (43) Haloscatella karekare, internal structures of male terminalia (aedeagus [shaded], phallapodeme, gonite+hypandrium), lateral; (44) Paracoenia bisetulosa, ventral receptacle lateral; (45) Notiocoenia paniculate, ventral receptacle lateral; (46)Scatella (Scatella) stagnalis, ventral receptacle lateral; (47)Philotelma defectum, ventral receptacle lateral.

Figures 48–62. Scatella fusca: (48) head, anterior; (49) head, lateral; (50) thorax, dorsal; (51) male mid leg, posterior; (52) epandrium and cerci posterior; (53) male internal terminalia, lateral.Scatella (Synhoplos) sturdeeanus: (54) head, lateral; (55) thorax, dorsal; (56) epandrium and cerci, posterior; (57) male terminalia, lateral. Scatella (Scatella) curtipennis: (58) head, anterior; 59, head, lateral; (60) thorax, dorsal; (61) epandrium and cerci, posterior; (62) male terminalia, lateral.