Scatophila picta Sturtevant and Wheeler

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 : 88-91

24. Scatophila picta Sturtevant and Wheeler

Figs. 167 , 204 , 212–216 , 223

Scatophila picta Sturtevant and Wheeler 1954: 196 .— Wirth 1965: 758 [ Nearctic catalog].— Zatwarnicki 1987: 293–294 [checklist].— Zatwarnicki and Mathis 1994: 366 [phylogeny, not placed in a species group].— Mathis and Zatwarnicki 1995: 285 [world catalog].

Diagnosis.—This species is distinguished from congeners by the following combination of characters: This species is mostly dark colored but with contrasted coloration; small shore flies, body length 1.80 mm.

Head ( Figs. 215–216 , 223 ): Frons mostly brown with gray spots anteriorly, 1 medially, and 2 laterally, just dorsad of antennal bases; fronto-orbits blackish brown with narrow, gray stripe immediately adjacent to eye. Face of ♂ with medial area very shallowly depressed to flat, ventral margin slightly projected, bearing several setulae; facial coloration gray except for inverted Y-shaped marking, each arm of Y robustly developed and with patch of setulae; oral margin with 2–3 stout setae on each side, above them with cluster of smaller setulae arising from a brown area. Gena moderately high, height subequal to height of basal flagellomere; gena-to-eye ratio 0.27.

Thorax ( Figs. 204 , 223 ): Mesonotum ( Fig. 223 ) generally mottled, mixture of brown and gray. Presutural dorsocentral setae lacking. Scutum mottled, generally mostly brown medially and mostly gray laterally, with linear gray spots between acrostichal rows subanteriorly and with gray vitta between acrostichal and dorsocentral tracks anteriorly. Scutellum mostly brown with a distinct basal and apical gray spots, lateral margins darkened; presutural dorsocentral setae lacking; pleural area extensively gray but with brown markings; anepisternum with large brown spot subdorsally; an irregular brown area at ventral portion of anepisternum and anepimeron and dorsal area of katepisternum. Wing ( Fig. 204 ) generally infuscate, brown with distinctive white spots and markings, length 2.00 mm; Cell r 1 with 4 white spots, apical spot less distinct; veins R 2+3 and R 4+5 shallowly sinuous; costal vein ratio 0.27; M 1 vein ratio 0.72. Knob of halter yellow. Femora and tibiae black; male midfemur lacking row of spine-like setulae along posteroventral margin; basitarsi yellow; other tarsomeres becoming darker with apical 1–2 brown.

Abdomen ( Figs. 212–214 ): Tergites dark brown from dorsal view; lateral and ventral portions with gray markings, especially toward posterior margins. Male terminalia ( Figs. 212–214 ): Epandrium in posterior view ( Fig. 212 ) generally irregularly rectangular, width almost 1/2 height, ventral margin somewhat truncate ( Fig. 212 ) with a very slight medial indentation, ventral margin only slightly wider than width of cercal opening; dorsal margin of epandrium in posterior view ( Fig. 212 ) broadly rounded, with very obtuse angles at corners, lateral margins widest at midheight, midheight indicated by lateral, shallow, bump, thereafter ventrally somewhat parallel sided to rounded posterolateral corner; epandrial setulae about equal in length, sparser medially and laterally, those along ventral and dorsal margins longer; width of cercal opening about 0.55 epandrial height, lateral margins sinuous, bulged at ventral 2/3, thereafter ventrally tapered to more narrowly rounded ventral margin; cerci in posterior view ( Fig. 212 ) robustly lunate, slightly more narrowed dorsally; aedeagus in lateral view ( Fig. 214 ) robustly and irregularly rounded basally, generally forming irregular triangle, posterior portion broadly and shallowly sinuously truncate, lateral margins tapered to ventral, narrowly rounded apex, lacking a dorsal cavity, but with a long, sinuous, dorsal thumb-like projection, in ventral view ( Fig. 213 ) bell-like, basal margin more narrowly rounded, thereafter flared toward ventral margin, ventrolateral corners angulate, ventral margin broadly and shallow rounded with a medial, shallow triangular notch; ventral aedeagal process sinuous; phallapodeme in lateral view ( Fig. 214 ) elongate, narrow, elbowed, dorsal extension about 1/3 ventral extension, dorsal extension with slightly expanded apical half, in ventral view ( Fig. 213 ) T-shaped, width of basal crossbar about half length of medial process, crossbar tapered laterally, another crossbar below, as an inverted, robust W; postgonite in lateral view ( Fig. 214 ) irregularly V-shaped, with dorsal arm somewhat rectangular, anteroventral corner produced, thumb-like but with acutely pointed apex, bearing setulae, ventral arm elongate, parallel-sided, nearly straight, in ventral view ( Fig. 213 ) 2 postgonites forming a Hlike structure with medially directed, narrow process at basal 2/3, apices rounded, bearing setulae along lateral and apical margins; neohypandrium in lateral view ( Fig. 214 ) narrow, deeply sinuous.

Type Material.—The holotype male of Scatophila picta is labeled “MatanuskaAlaska Oct.2 1945 RotaryTrapColl J.C.Chamberlin [“2” and “5” handwritten]/ HOLOTYPE Scatophila picta Stvt & Whlr [pink].” The holotype is double mounted (glued to a paper triangle), is in excellent condition, and is deposited in the USNM.

Type Locality.— United States. Alaska. Matanuska-Susitna: Matanuska (61°32.5'N, 149°13.8'W) .

Distribution ( Fig. 167 ).— Nearctic : United States (Alaska).

Remarks.—This species is placed in the quadriguttata group, and is only known, thus far, from the holotype male.

Figures

FIGURE 167. Distribution map of Scatophila bisignata Cresson (circles), and S. picta Sturtevant & Wheeler (square).

FIGURES 202–204. Head, thorax, and wing of Scatophila. 202. S. hirsuta Sturtevant & Wheeler, head and thorax, dorsal view. 203. S. mystacina sp. nov. male, wing, dorsal view. 204 S. picta Sturtevant & Wheeler, wing, dorsal view. Scale bar = 0.2 mm.

FIGURES 212–214. Male terminalia of Scatophila picta Sturtevant & Wheeler. 212. Epandrium and cerci, posterior view. 213. Internal male terminalia (gonite, phallapodeme, aedeagus, neohypandrium), ventral view. 214. Same, lateral view. Scale bar = 0.1 mm.

FIGURES 215–219. Head, thorax, and wing of Scatophila. 215–216. Head of Scatophila picta Sturtevant & Wheeler. 215. Latero-oblique view. 216. Lateral view. 217. Scatophila mystacina sp. nov., head and thorax, dorsal view. 218–219. Wing, dorsal view. 218. S. pulchra Sturtevant & Wheeler. 219. S. rubribrunnea Sturtevant & Wheeler. Scale bar = 0.2 mm.

FIGURES 221–225. Head and thorax of Scatophila. 221–222. Head of S. pulchra Sturtevant & Wheeler. 221. Latero-oblique view. 222. Lateral view. 223–225. Head and thorax, dorsal view. 223. Scatophila picta Sturtevant & Wheeler. 224. S. pulchra Sturtevant & Wheeler. 225. S. rubribrunnea Sturtevant & Wheeler. Scale bar = 0.2 mm.