Scatophila Becker

Zatwarnicki, Tadeusz & Mathis, Wayne N., 2024, Revision of the Nearctic Species of the Shore-Fly Genus Scatophila Becker (Diptera: Ephydridae), Zootaxa 5487 (1), pp. 1-100 : 9-13

publication ID

https://doi.org/ 10.11646/zootaxa.5487.1.1

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lsid:zoobank.org:pub:50AC1672-FC20-4502-8D8A-4BCAE95F719B

DOI

https://doi.org/10.5281/zenodo.13243592

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https://treatment.plazi.org/id/03D187B7-3A5B-7B5F-FF4E-F9E352F6FA87

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scientific name

Scatophila Becker
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Genus Scatophila Becker View in CoL

Scatophila Becker 1896: 237–245 . Type species: Ephydra caviceps Stenhammar 1844 , by original designation.— Becker 1905: 212–214 [Palearctic catalog]; 1926: 86–91 [review of Palearctic species].— Cresson 1930: 128–131 [notes].— Sturtevant and Wheeler 1954: 183–201 [revision of Nearctic species].— Wirth 1965: 758–759 [catalog of Nearctic species]; 1968: 27–28 [catalog of Neotropical species].— Dahl 1959: 127–130 [review of Scandinavian species].— Papp 1975b: 123–128 [review of Hungarian species].— Cogan 1984: 169–171 [catalog of Palearctic species].— Zatwarnicki 1987: 277–298 [notes, synonymies of species].— Zatwarnicki and Mathis 1994: 351–370 [classification, phylogeny].— Mathis and Zatwarnicki 1995: 281–288 [world catalog].

Centromeromyia Frey 1954: 40 . Type species: Centromeromyia eremita Frey 1954 , original designation.—Zatwarnicki 1991: 329 [synonymy].

Diagnosis. Scatophila is distinguished from other genera of the tribe Scatellini by the following combination of characters: 1 fronto-orbital seta (some Neotropical species have 2); costa relatively short, extended to vein R 4+5; crossvein r-m distinctly distal to subcostal break.

Description. Tiny to moderately small shore flies, body length 0.80–2.70 mm.

Head: Frons dull usually with distinct, subshiny to shiny ocellar triangle; generally 1 fronto-orbital seta (some Neotropical species with 2). Antenna short, dark colored; pedicel setae typical; basal flagellomere round; arista almost bare, without long dorsal branches. Face projected, sometimes central portion membranous and distinctly incised or oral margin with a protruded, narrow, sometimes spine-like projection (sexual dimorphism is frequently evident in the conformation of the face); facial setae conspicuous, lateral facial setae ventrally curved, usually indistinctly from medial facial setae, inserted mostly in the middle and ventral portions of face, 4–8 setae on the oral margin. Eye nearly round or obliquely ovate. Genal seta generally present; genal height short to high, gena-to-eye ratio 0.14–0.55. Maxillary palpus elongate, mostly dark, yellow as an exception; proboscis of Scatophila is generally typical for Scatellini with rounded posterodorsal margin of the rostrum ( Fig. 3 View FIGURES 3–5 ), and 5 pseudotracheae (as mentioned by Bolwig (1941) for S. unicornis Czerny ); pseudotracheal rings ended by attachments ( Tuxen (1944) called these “scrapers”); in most Scatellini the cibarium bears 2 dorsolateral parallel bands, as shown by Andersson (1967, figs. 1 A –1C, page 109) and Zatwarnicki (2023, fig. 23, page 668), which are reduced in Scatophila ( Fig. 4 View FIGURES 3–5 ).

Thorax: Mesonotum microtomentose, appearing with a multicolored pattern of bands and/or spots in many species; postsutural dorsocentral setae usually 2, rarely 3 (then with 1 presutural seta); acrostichal setae in 2 rows, extended to scutellum, equal in length; scutellum flat, disc bare, bearing 2 posterior setae laterally, basal scutellar setae smaller than apical setae; pleurae generally gray, lighter than mesonotum, posterior anepisternal seta well developed. Wing faintly to conspicuously infuscate with white spots distributed over most of wing, but exceptionally within cell r 1; costa short, extended to vein R 4+5; crossvein r-m distinctly distal to subcostal break; wings reduced in a few species; stem of halter short, head oval, white. Legs typical, usually without distinct setae (ventral row of spinulae on mid tibiae of males of some species); color of tarsi variable; tarsal claws conspicuously curved and pulvilli present below each claw.

Abdomen: Tergites gray, microtomentose, sometimes with lighter posterior margins, or entirely shiny black. Male terminalia: Sternite 5 present, sternite 6 absent. Epandrium a closed plate; cercal opening circular to oval; cerci lunate to hemispherical; dorsal epandrial margin rounded, ventral epandrial margin straight or slightly convex to incised medially forming two lateral lobate process; phallapodeme elongate, curved or angular, sometimes with slightly raised keel; postgonites V-shaped, asymmetrical, usually sharply terminated posteriorly, sometimes bearing setae on dorsal margin of anterior portion; hypandrium, when present, as an inverted V-shaped structure bounded with the postgonites or as a more or less sinuous band; phallapodeme in lateral view shallowly curved or angulate, keel not evident or shallow, in ventral view usually T-shaped, with basal crossbar; aedeagus shoe-shaped in lateral view, in most species bearing narrow, un- or paired sinuous ventral process that originates from ventral side of distal aedeagal margin; ejaculatory apodeme lacking. Female Terminalia: sternite 8 divided, as 2 lateral, subquadrate sclerites, bearing a long seta on posterior margin; female cerci without prominent setae. Operculum of ventral receptacle helmet-like, somewhat round, covering extended process.

Natural history.—Like most taxa included in the tribe Scatellini , the habitats where adults of Scatophila are found have sandy or muddy shores that are associated with lentic, freshwater systems, although some species are associated with inland alkaline or saline habitats. Deonier (1974) suggested that adults feed on algae and bacteria. Immature stages are known for only two species: Scatophila unicornis and Scatophila iowana ( Bolwig 1940a, Deonier 1974).

Among shore flies, brachyptery is disproportionally expressed in species of the tribe Scatellini , including Scatophila , which has two described species with brachypterous wings: S. gorodkovi ( Krivosheina and Ozerov 2016; Russia. Chukotka: Wrangel Island. Mineeva Mountains; near lemming hole), and S. stenoptera ( Papp 1979; Papua New Guinea. Mount Wilhelm, slightly below Brass Tarn). In addition to these described species, at least two undescribed brachypterous species are known from the austral Neotropics.

Discussion.— Scatophila currently comprises 50 species of which most occur in the Holarctic Region ( Mathis and Zatwarnicki 1995 and electronic updates). Zatwarnicki and Mathis (1994) proposed nine species groups for these species on a global basis, and of the nine species groups, five include species that are found in the Nearctic Region. The species groups were characterized primarily using structures of the male terminalia and these structures are likewise used extensively herein to recognize species. To facilitate the identification of species and to provide morphological evidence for how these species are classified, we provide detailed illustrations and descriptions of these structures, most for the first time. In addition, numerous photographs of key external characters are included. A key to the five species groups found in the Nearctic Region follows this discussion and is immediately followed by a key to the known Nearctic species.

Key to Species Groups of Scatophila Occurring in the Nearctic Region based primarily on structures of the male terminalia

1. Aedeagus lacking a ventral process ( Figs. 13 View FIGURES 11–13 , 20 View FIGURES 18–20 , 29 View FIGURES 27–29 , 36 View FIGURES 34–36 )...................................................... 2

- Aedeagus with a ventral process, sinuous ( Figs. 44 View FIGURES 42–44 , 55 View FIGURES 53–55 , 63 View FIGURES 61–63 , 70 View FIGURES 67–70 , 80 View FIGURES 77–80 , 88 View FIGURES 86–88 , 99 View FIGURES 97–99 , 106 View FIGURES 104–106 , 118 View FIGURES 115–118 , 124 View FIGURES 122–124 , 136 View FIGURES 134–136 , 144 View FIGURES 142–144 , 155 View FIGURES 153–155 , 166 View FIGURES 164–166 , 174 View FIGURES 172–174 , 182 View FIGURES 180–182 , 190 View FIGURES 188–190 , 201 View FIGURES 199–201 , 207 View FIGURES 205–207 , 214 View FIGURES 212–214 , 228 View FIGURES 226–228 , 235 View FIGURES 233–235 )................................................................................ 3

2. Neohypandrium absent ( Figs. 28–29 View FIGURES 27–29 ; 35–36 View FIGURES 34–36 )................................................ The despecta Group

- Neohypandrium present ( Figs. 12–13 View FIGURES 11–13 , 19–20 View FIGURES 18–20 )............................................. The contaminata Group

3. Fold on dorsal aedeagal opening convex with lateral processes ( Figs. 43 View FIGURES 42–44 , 54 View FIGURES 53–55 , 62 View FIGURES 61–63 , 69 View FIGURES 67–70 , 79 View FIGURES 77–80 , 87 View FIGURES 86–88 )....... The mesogramma Group

- Fold on dorsal aedeagal opening generally angulate, sometimes incised medially, but without lateral processes ( Figs. 99 View FIGURES 97–99 , 106 View FIGURES 104–106 , 118 View FIGURES 115–118 , 124 View FIGURES 122–124 , 136 View FIGURES 134–136 , 144 View FIGURES 142–144 , 155 View FIGURES 153–155 , 166 View FIGURES 164–166 , 174 View FIGURES 172–174 , 182 View FIGURES 180–182 , 190 View FIGURES 188–190 , 201 View FIGURES 199–201 , 207 View FIGURES 205–207 , 214 View FIGURES 212–214 , 228 View FIGURES 226–228 , 235 View FIGURES 233–235 )............................................ 4

4. Fold on dorsal aedeagal opening incised medially or broadly semicircular ( Figs. 98 View FIGURES 97–99 , 105 View FIGURES 104–106 , 117 View FIGURES 115–118 , 123 View FIGURES 122–124 , 135 View FIGURES 134–136 ); sometimes distal margin of epandrium with lateral processes or with broad medial projection ( Figs. 97 View FIGURES 97–99 , 104 View FIGURES 104–106 , 116 View FIGURES 115–118 , 122 View FIGURES 122–124 , 134 View FIGURES 134–136 )..................................................................................................... The noctula Group

- Fold on dorsal aedeagal opening with medial process or exceptionally flat ( Figs. 143 View FIGURES 142–144 , 154 View FIGURES 153–155 , 165 View FIGURES 164–166 , 173 View FIGURES 172–174 , 181 View FIGURES 180–182 , 189 View FIGURES 188–190 , 200 View FIGURES 199–201 , 206 View FIGURES 205–207 , 213 View FIGURES 212–214 , 227 View FIGURES 226–228 , 234 View FIGURES 233–235 ), often distal margin of epandrium with sharp medial process, sometimes concave ( Figs. 164 View FIGURES 164–166 , 180 View FIGURES 180–182 , 188 View FIGURES 188–190 , 199 View FIGURES 199–201 , 205 View FIGURES 205–207 , 233 View FIGURES 233–235 )............................................................................. The quadriguttata Group

Key to Nearctic Species of Scatophila (some couplets for males)

1. A presutural pair of dorsocentral setae present ( Figs. 175, 177 View FIGURES 175–179 )................................................. 2

- Presutural dorsocentral setae lacking ( Fig. 5 View FIGURES 3–5 , 10 View FIGURES 6–10 , 22 View FIGURES 22–26 , 31 View FIGURES 31–33 , 45 View FIGURES 45–47 , 58–60 View FIGURES 56–60 , 74 View FIGURES 72–76 , 89 View FIGURES 89–91 , 107 View FIGURES 107–109 , 119–121 View FIGURES 119–121 , 137 View FIGURES 137–141 , 145 View FIGURES 145–147 , 156 View FIGURES 156–158 , 176 View FIGURES 175–179 , 202 View FIGURES 202–204 , 217 View FIGURES 215–219 , 223– 225 View FIGURES 221–225 )................................................................................................ 3

2. Cell r 1 with 2–3 white spots; wing spots generally conspicuous ( Fig. 147 View FIGURES 145–147 ); halter and basal tarsomeres pale; fronto-orbital plate not densely microtomentose ( Fig. 160, 162 View FIGURES 160–163 )................................................. S. bisignata Cresson

- Cell r 1 lacking spots; wing spots small and indistinct ( Fig. 158 View FIGURES 156–158 ); halter and tarsi dark; fronto-orbital plate densely microtomentose, appearing velvety black ( Fig. 178 View FIGURES 175–179 )..................................................... S. cribrata (Stenhammar)

3. Cell r 1 with 2 or more distinct white spots ( Figs. 109 View FIGURES 107–109 , 204 View FIGURES 202–204 )..................................................... 4

- Cell r 1 lacking spots, or with a single, weak, basal white area, or wings very pale, not appearing spotted ( Figs. 8–9 View FIGURES 6–10 , 23–24 View FIGURES 22–26 , 32–33 View FIGURES 31–33 , 46–47 View FIGURES 45–47 , 75–76 View FIGURES 72–76 , 90–91 View FIGURES 89–91 , 108 View FIGURES 107–109 , 138–139 View FIGURES 137–141 , 146 View FIGURES 145–147 , 157 View FIGURES 156–158 , 192–193 View FIGURES 191–193 , 203 View FIGURES 202–204 , 218–219 View FIGURES 215–219 ).................................... 5

4. Scutellum with a distinct basal gray triangle ( Fig. 223 View FIGURES 221–225 ); face of ♂ flat, the oral margin with 2–3 stout setae on each side, above them a cluster of smaller setulae arising from a brown area ( Figs. 215–216 View FIGURES 215–219 )............... S. picta Sturtevant and Wheeler

- Scutellum indistinctly marked ( Fig. 121 View FIGURES 119–121 ); face of ♂ with a snout-like protuberance ventromedially ( Figs. 125–126 View FIGURES 125–128 )............................................................................................ S. unicornis Czerny

5. Quadrate white spot of cell r 3 with a prominent dark center ( Fig. 218 View FIGURES 215–219 ); face yellowish ( Fig. 221–222 View FIGURES 221–225 )............................................................................................. S. pulchra Sturtevant and Wheeler

- Large, quadrate white spot of cell r 3 lacking a dark center ( Figs. 8–9 View FIGURES 6–10 , 23–24 View FIGURES 22–26 , 32–33 View FIGURES 31–33 , 46–47 View FIGURES 45–47 , 75–76 View FIGURES 72–76 , 90–91 View FIGURES 89–91 , 108 View FIGURES 107–109 , 138–139 View FIGURES 137–141 , 146 View FIGURES 145–147 , 157 View FIGURES 156–158 , 192–193 View FIGURES 191–193 , 203 View FIGURES 202–204 , 219 View FIGURES 215–219 ); facial coloration variable, dark to whitish gray ( Figs. 38–41 View FIGURES 38–41 , 49–52 View FIGURES 49–52 , 65–66 View FIGURES 65–66 , 82–85 View FIGURES 82–85 , 93–96 View FIGURES 93–96 , 100–103 View FIGURES 100–103 , 111–114 View FIGURES 111–114 , 130–133 View FIGURES 130–133 , 140–141 View FIGURES 137–141 , 149–152 View FIGURES 149–152 , 168–171 View FIGURES 168–171 , 184–187 View FIGURES 184–187 , 195–198 View FIGURES 195–198 , 208–211 View FIGURES 208–211 , 229–232 View FIGURES 229–232 )............................ 6

6. Larger facial seta inserted toward posteroventral corner curved upward and outward ( Fig. 1 View FIGURES 1–2 , 16–17 View FIGURES 14–17 , 25–26 View FIGURES 22–26 ), as in Scatella ; midfemora of ♂ bearing a row of short spine-like setae along posteroventral margin................................ 7

- Lower facial seta not oriented upward and outward ( Figs. 14 View FIGURES 14–17 , 38, 40 View FIGURES 38–41 , 49, 51 View FIGURES 49–52 , 56 View FIGURES 56–60 , 72 View FIGURES 72–76 , 82, 84 View FIGURES 82–85 , 93, 95 View FIGURES 93–96 , 100, 102 View FIGURES 100–103 , 111, 113 View FIGURES 111–114 , 130, 132 View FIGURES 130–133 , 195, 197 View FIGURES 195–198 , 229, 231 View FIGURES 229–232 ); midfemora of ♂ lacking row of spine-like setae............................................. 8

7. Epandrium diamond-shaped in posterior view, ventral third in posterior view conspicuously narrowed ( Fig. 27 View FIGURES 27–29 ), width about equal to width of cercal cavity, ventral emargination shallow, rounded vertex; postgonites in ventral view nearly straight, tapered from wider base ( Fig. 28 View FIGURES 27–29 ).......................................................... S. angusta sp. nov.

- Epandrium ovate in posterior view with ventral third conspicuously wider than width of cercal cavity ( Fig. 34 View FIGURES 34–36 ), ventral emargination wide, deeply and broadly V-shaped, vertex angulate; postgonites in ventral view conspicuously curved medially ( Fig. 35 View FIGURES 34–36 )............................................................................ S. variabilis Cresson

8. Body tan, brown, or black, usually with some lighter markings, scutellar disc mostly dark but often with basal and sometimes with apical areas gray ( Figs. 5 View FIGURES 3–5 , 10 View FIGURES 6–10 , 45 View FIGURES 45–47 , 58–59 View FIGURES 56–60 , 74 View FIGURES 72–76 , 89 View FIGURES 89–91 , 107 View FIGURES 107–109 , 119–120. 137 View FIGURES 119–121 View FIGURES 122–124 View FIGURES 125–128 View FIGURE 129 View FIGURES 130–133 View FIGURES 134–136 View FIGURES 137–141 , 202 View FIGURES 202–204 , 225 View FIGURES 221–225 )................................. 9

- Body mostly whitish to grayish white, usually with some darker markings, scutellar disc mostly to entirely whitish ( Fig. 60 View FIGURES 56–60 , 145 View FIGURES 145–147 , 156 View FIGURES 156–158 , 176 View FIGURES 175–179 , 191 View FIGURES 191–193 , 217 View FIGURES 215–219 )............................................................................... 21

9. Body short, body length 1.10–1.60 mm, extensively blackish brown to black ( Fig. 5 View FIGURES 3–5 ); tergites shiny black; knob of halter blackish; gena very short, gena-to-eye ratio 0.12 ( Fig. 7 View FIGURES 6–10 )............................... S. contaminata (Stenhammar)

- Body size variable but usually larger, mesonotum with some grayish areas ( Figs. 10 View FIGURES 6–10 , 45 View FIGURES 45–47 , 58–59 View FIGURES 56–60 , 74 View FIGURES 72–76 , 89 View FIGURES 89–91 , 107 View FIGURES 107–109 , 119–120. 137 View FIGURES 119–121 View FIGURES 122–124 View FIGURES 125–128 View FIGURE 129 View FIGURES 130–133 View FIGURES 134–136 View FIGURES 137–141 , 202 View FIGURES 202–204 , 225 View FIGURES 221–225 ); tergites not entirely shiny; knob of halter pale, usually yellowish; gena higher, usually above 0.20 ( Figs. 15, 17 View FIGURES 14–17 , 39, 41 View FIGURES 38–41 , 50, 52 View FIGURES 49–52 , 57 View FIGURES 56–60 , 73 View FIGURES 72–76 , 83, 85 View FIGURES 82–85 , 94, 96 View FIGURES 93–96 , 101, 103 View FIGURES 100–103 , 112, 114 View FIGURES 111–114 , 131, 133 View FIGURES 130–133 , 196, 198 View FIGURES 195–198 , 230, 232 View FIGURES 229–232 )................................... 10

10. Acrostichal setae of uniform, small size, arranged in 2 regular rows ( Figs. 59 View FIGURES 56–60 , 74 View FIGURES 72–76 ); scutum generally tannish with scutal pattern not or barely evident.................................................................................. 11

- Acrostichal setae usually irregular in size and arrangement, rarely formed in 2 regular rows ( Fig. 10 View FIGURES 6–10 , 45 View FIGURES 45–47 , 58 View FIGURES 56–60 , 89 View FIGURES 89–91 , 107 View FIGURES 107–109 , 119–120. 137 View FIGURES 119–121 View FIGURES 122–124 View FIGURES 125–128 View FIGURE 129 View FIGURES 130–133 View FIGURES 134–136 View FIGURES 137–141 , 202 View FIGURES 202–204 , 225 View FIGURES 221–225 ), scutal pattern usually evident ( Fig. 10 View FIGURES 6–10 , 45 View FIGURES 45–47 , 58 View FIGURES 56–60 , 89 View FIGURES 89–91 , 107 View FIGURES 107–109 , 119–120 View FIGURES 119–121 , 137 View FIGURES 137–141 , 202 View FIGURES 202–204 , 225 View FIGURES 221–225 )...................... 12

11. Epandrium with ventral margin widely concave, width much wider than width of cercal cavity ( Fig. 77 View FIGURES 77–80 ), produced laterally as a thumb-like, short, process................................................. S. ordinaria Sturtevant and Wheeler

- Epandrium with ventral margin truncate, width about equal to width of cercal cavity, not produced laterally ( Fig. 61 View FIGURES 61–63 )............................................................................................ S. iowana Wheeler

12. A prescutellar pair of acrostichal setae well developed, subequal to length of ocellar setae ( Fig. 10 View FIGURES 6–10 ); small species, length 1.40– 1.55 mm, scutal pattern gray ( Fig. 10 View FIGURES 6–10 ); wings highly spotted ( Fig. 9 View FIGURES 6–10 ); legs black; cephalic setae well developed ( Fig. 14–15 View FIGURES 14–17 ); ♂ and ♀ with similar faces.................................................................... S. exilis Cresson

- Presutural acrostichal setae at most slightly enlarged ( Fig. 45 View FIGURES 45–47 , 58–59 View FIGURES 56–60 , 74 View FIGURES 72–76 , 89 View FIGURES 89–91 , 107 View FIGURES 107–109 , 119–120. 137 View FIGURES 119–121 View FIGURES 122–124 View FIGURES 125–128 View FIGURE 129 View FIGURES 130–133 View FIGURES 134–136 View FIGURES 137–141 , 202 View FIGURES 202–204 , 225 View FIGURES 221–225 ); face of ♂ and ♀ sexually dimorphic, ♂ concave, flattened, protuberant, incised, tuberculate or otherwise modified from female type ( Figs. 38–41 View FIGURES 38–41 , 49–52 View FIGURES 49–52 , 82–85 View FIGURES 82–85 , 93–96 View FIGURES 93–96 , 100–103 View FIGURES 100–103 , 111–114 View FIGURES 111–114 , 195–198 View FIGURES 195–198 , 229–232 View FIGURES 229–232 )........................................... 13

13. Abdomen black, noticeably shiny, especially on posterior tergites, basal tergites at most thinly microtomentose.......... 14

- Abdomen brown to black, rather heavily microtomentose, rarely subshiny....................................... 18

14. Wing yellow at base, otherwise with a conspicuous pattern of white spots in largely infuscate remigium ( Fig. 33 View FIGURES 31–33 ); scutellum with a distinct basal, gray triangle ( Fig. 58 View FIGURES 56–60 ); face of ♂ flat to concave ( Figs. 49–50 View FIGURES 49–52 ), the margin protuberant, grayish to more golden yellow............................................................. S. hesperia Sturtevant and Wheeler

- Wing not strongly yellow at base ( Figs. 90–91 View FIGURES 89–91 , 108 View FIGURES 107–109 , 138 View FIGURES 137–141 ); scutellum with indistinct basal, gray area or none ( Figs. 107 View FIGURES 107–109 , 119– 120 View FIGURES 119–121 , 137 View FIGURES 137–141 ); face more brown than yellow, that of ♂ not shaped as above ( Figs. 93–94 View FIGURES 93–96 , 100–101 View FIGURES 100–103 , 111–112 View FIGURES 111–114 , 130–131 View FIGURES 130–133 )....... 15

15. Face of ♂ with a stout medial conical tubercle nearly as large as basal flagellomere ( Figs. 100–101 View FIGURES 100–103 ), invested with setulae. Ventral epandrial margin essentially truncate, not bifurcate medially or with ventrolateral extensions.......................................................................................... S. hirtirostris Sturtevant and Wheeler

- Face of ♂ not as above ( Figs. 93–94 View FIGURES 93–96 , 111–112 View FIGURES 111–114 , 130–131 View FIGURES 130–133 ). Ventral epandrial margin with ventrolateral extensions or bifurcate medially........................................................................................... 16

16. Scutum subshiny ( Figs. 107 View FIGURES 107–109 , 137 View FIGURES 137–141 ); tarsi often yellow basally; face of ♂ brown, protuberant at ventral margin, with an elongate, medial depression bordered by dense curly setulae ( Figs. 93–94 View FIGURES 93–96 , 130–131 View FIGURES 130–133 ), especially laterally; face of ♀ with some subshiny luster ( Figs. 95–96 View FIGURES 93–96 , 132–133 View FIGURES 130–133 ); ventral epandrial margin with ventrolateral extensions, these narrow ( Figs. 97 View FIGURES 97–99 , 134 View FIGURES 134–136 )....... 17

- Scutum wholly densely microtomentose, appearing dull ( Fig. 120 View FIGURES 119–121 ); tarsi mostly brown or black; face of ♂ with a low medial ridge invested with fine setulae ( Figs. 111–112 View FIGURES 111–114 ); face of ♀ brown, microtomentose, not subshiny or lustrous ( Figs. 113–114 View FIGURES 111–114 ); ventral epandrial margin bifurcate medially, each lateral lobe robustly developed ( Fig. 115 View FIGURES 115–118 )......... S. tuberculosa Cresson

17. Epandrium with ventrolateral extensions small, narrow, length about equal to width of a cercus ( Fig. 97 View FIGURES 97–99 ); aedeagus in ventral view ( Fig. 98 View FIGURES 97–99 ) pentagonal; keel of phallapodeme small, thumb-like................................ S. bolwigi sp. nov.

- Epandrium with ventrolateral extensions large, length equal to height of a cercus ( Fig. 134 View FIGURES 134–136 ); aedeagus in ventral view ( Fig. 135 View FIGURES 134–136 ) rectangular; keel of phallapodeme robust, length almost as long as either arm of phallapodeme.............................................................................................. S. variofacialis Sturtevant and Wheeler

18. Distance between reclinate fronto-orbital seta and medial vertical seta subequal to that between inner and lateral vertical setae ( Figs. 38, 40 View FIGURES 38–41 ); tarsi usually, and sometimes tibiae, pale; face of ♂ with medial indentation at margin ( Fig. 38 View FIGURES 38–41 ) and bearing cluster of long setulae and setae on each side................................................. S. adamsi Cresson

- Reclinate fronto-orbital farther from medial vertical seta than the latter is from the lateral vertical seta ( Fig. 84 View FIGURES 82–85 , 195, 197 View FIGURES 195–198 , 229, 231 View FIGURES 229–232 ); tarsi usually dark but paler in viridella ; face of ♂ not as above ( Figs. 82–83 View FIGURES 82–85 , 195–196 View FIGURES 195–198 , 229–230 View FIGURES 229–232 )................. 19

19. Gena about as high as width of basal flagellomere ( Fig. 83, 84 View FIGURES 82–85 ); frontal triangle scarcely differentiated in color from anterior non-fronto-orbital plate ( Fig. 82, 84 View FIGURES 82–85 ); scutum usually with an olive tint ( Fig. 89 View FIGURES 89–91 ); maxillary palpus pale; tarsi usually partially pale..................................................................... S. viridella Sturtevant and Wheeler

- Gena shorter than width of basal flagellomere ( Figs. 196, 198 View FIGURES 195–198 , 230, 232 View FIGURES 229–232 ); frontal triangle and fronto-orbital plate dull brown, leaving black triangular areas along anterior margin of frons ( Figs. 195, 197 View FIGURES 195–198 , 229, 231 View FIGURES 229–232 ); maxillary palpus and tarsi mostly dark............................................................................................... 20

20. Scutum with medial anterior dark stripe almost black ( Fig. 202 View FIGURES 202–204 ), pale areas on each side of it scarcely visible; dorsum of postpronotum noticeably microtomentose; face of ♂ flat in center, never membranous, the oral margin rather straight ( Figs. 195–196 View FIGURES 195–198 ).................................................................. S. hirsuta Sturtevant and Wheeler

- Scutum with medial anterior dark stripe not much darker than other markings ( Fig. 225 View FIGURES 221–225 ); pale marks over postpronotum continuous with dorsal marks on each side of medial stripe; face of ♂ sunken in middle, usually membranous to a noticeable degree; oral margin protuberant ( Figs. 229–230 View FIGURES 229–232 ).............................. S. rubribrunnea Sturtevant and Wheeler

21. Wings mostly pale, whitish, a spotted pattern scarcely evident ( Fig. 47 View FIGURES 45–47 ); gena broad, more than twice as wide as width of basal flagellomere ( Fig. 66 View FIGURES 65–66 ); coastal species................................................... S. mesogramma (Loew)

- Wings darker, a spotted pattern usually evident ( Figs. 139 View FIGURES 137–141 , 146 View FIGURES 145–147 , 192 View FIGURES 191–193 , 203 View FIGURES 202–204 ; but pale in S. conifera , Fig. 157 View FIGURES 156–158 ); gena narrower than above ( Figs. 141 View FIGURES 137–141 , 150, 152 View FIGURES 149–152 , 169, 171 View FIGURES 168–171 , 185, 187 View FIGURES 184–187 , 209, 211 View FIGURES 208–211 ); western to southwestern species.......................... 22

22. Face of ♂ flat or concave in middle ( Fig. 145 View FIGURES 145–147 , 184–185 View FIGURES 184–187 ); pedicel thickly setulose along medial margin................. 23

- Face of ♂ prominently convex medially ( Fig. 149–150 View FIGURES 149–152 , 168–169 View FIGURES 168–171 , 208–209 View FIGURES 208–211 ); pedicel with sparse setulae; face of ♀ without a pair of divergent setae on upper carina ( Figs. 151–152 View FIGURES 149–152 , 170–171 View FIGURES 168–171 , 210–211 View FIGURES 208–211 )...................................... 24

23. Face of ♂ flat to slightly concave medially, not membranous ( Fig. 145 View FIGURES 145–147 ); 2–3 facial setae along margin at each side rather pale and weak; coloration nearly uniformly whitish, abdomen mostly whitish microtomentose; face of ♀ silvery gray, gena wider than width of basal flagellomere ( Figs. 140–141 View FIGURES 137–141 )............................................. S. arenaria Cresson

- Face of ♂ concave, membranous medially behind oral margin ( Fig. 184–185 View FIGURES 184–187 ); 2–3 stout black setae on each side stronger than those of S. arenaria ; less whitish, especially on abdomen; face of ♀ with a pair of divergent setae on upper carina ( Figs. 186–187 View FIGURES 184–187 )............................................................................. S. disjuncta Cresson

24. Face of ♂ evenly arched in middle ( Figs. 149–150 View FIGURES 149–152 ), thickly setulose, especially 2 large lateral clusters in which 3–5 are stronger; wing spots distinct, including apical spot of cell r 3 ( Fig. 146 View FIGURES 145–147 ); face of ♀ gray with some brownish discoloration ( Figs. 151–152 View FIGURES 149–152 )................................................................ S. bipiliaris Sturtevant and Wheeler

- Face of ♂ protuberant, medial portion forming a broad cone that involves the oral margin ( Figs. 168–169 View FIGURES 168–171 , 208–209 View FIGURES 208–211 ), broad cone surrounded by clustered setae except at margin; wing spots rather indistinct ( Figs. 157 View FIGURES 156–158 , 203 View FIGURES 202–204 )......................... 25

25. Facial protuberance of ♂ pronounced ( Fig. 208–209 View FIGURES 208–211 ), bearing numerous prominent curved black setulae, postgonite in ventral view ( Fig. 206 View FIGURES 205–207 ) with basal margin excavated, very broadly V-shaped; phallapodeme in ventral with crossbar shallowly concave............................................................................. S. mystacina sp. nov.

- Facial protuberance of ♂ and setulae on each side of protuberance smaller ( Figs. 168–169 View FIGURES 168–171 ). Postgonite in ventral view ( Fig. 173 View FIGURES 172–174 ) with basal margin sloped toward apex, not excavated; phallapodeme in ventral with crossbar nearly straight, not concave........................................................................ S. conifera Sturtevant and Wheeler

R

Departamento de Geologia, Universidad de Chile

A

Harvard University - Arnold Arboretum

Kingdom

Animalia

Phylum

Arthropoda

Class

Insecta

Order

Diptera

Family

Ephydridae

Tribe

Scatellini

GBIF Dataset (for parent article) Darwin Core Archive (for parent article) View in SIBiLS Plain XML RDF