Neoephydra prionoptera (Thomson)

Mathis, Wayne N. & Marinoni, Luciane, 2016, Revision of Ephydrini Zetterstedt (Diptera: Ephydridae) from the Americas south of the United States, Zootaxa 4116 (1), pp. 1-110 : 67-69

21. Neoephydra prionoptera (Thomson)

Figs. 92–94 , Map 21

Ephydra prionoptera Thomson 1868: 590 .— Hendel 1930: 150 [review].— Cresson 1931: 85 [review].

Dimecoenia prionoptera .— Hendel 1933: 223 [generic combination].— Edwards 1933: 119.— Cresson 1935: 350 [review].— Oliveira 1954a: 188 [list].— Wirth 1968: 23 [Neotropical catalog].—Lizarralde de Grosso 1989: 58 [list, Argentina].— Mathis and Zatwarnicki 1995: 239 –240 [world catalog].

Neoephydra prionoptera .— Mathis 2008: 10 [generic combination].

Dimecoenia densa Cresson 1931: 105 .— Edwards 1933: 119 [synonymy].

Dimecoenia travassosi Mello and Oliveira 1992: 137 [ Brazil. Rio de Janeiro, Santa Cruz; HT ♂, IOC (50016)]. New synonym

Neoephydra travassosi .— Mathis 2008: 10 [generic combination].

Diagnosis. Specimens of N. prionoptera are distinguished from similar congeners of the araucaria group by the following characters: appearance generally dark, particularly the legs; face moderately setose; gena moderately high; and structures of male terminalia with distinctive conformation. Medium-sized to moderately large shore flies, body length 3.80–4.95 mm; generally dull, grayish brown to gray with some subshiny areas dorsally.

Head: Head ratio 0.57–0.60; frontal ratio 0.47–0.51; mesofrons with dark, blackish blue, metallic luster; ocellar triangle and parafrons nearly concolorous, microtomentose, brownish gray to charcoal gray; parafrons becoming more charcoal colored anteriorly; fronto-orbits with narrow strip through insertions of fronto-orbital setae subshiny, with some faint metallic luster; number of fronto-orbital setae 2. Antenna mostly concolorous, blackish brown. Facial ratio 0.82; mostly moderately setulose particularly along oral margin and toward posteroventral portions of face; dorsum of interfoveal hump with subshiny area more or less concolorous with mesofrons, otherwise face densely microtomentose, grayish brown to gray, becoming gradually paler ventrally. Eye ratio 0.89–0.93; gena-to-eye ratio 0.40–0.43; gena high, coloration gray to whitish gray but with faint tinges of olivaceous green.

Thorax: Mostly microtomentose; mesonotum mostly brown, darker and subshinier posteriorly; anterior margin microtomentose, gray to bluish gray, subshiny luster concolorous with mesofrons; pleural areas paler, grayer ventrally; anepisternum mostly gray to olivaceous, often with some faint bluish or greenish metallic coloration and usually with diffuse, brown area toward posterior margin; other pleural areas including coxae whitish gray, concolorous. Wing length averaging 3.34 mm; mostly very palely infuscate, faintly grayish brown; costal vein ratio 0.34; M vein ratio 0.67. Legs dark generally; femora gray, microtomentose, only slightly darker than ventral pleural areas; tibiae and tarsi reddish yellow.

Abdomen: Generally microtomentose and unicolorous, grayish olivaceous green to gray, becoming paler toward lateral margins, some specimens with faint bluish tinges of metallic luster; ventral surface of tergites frequently whitish gray. Fifth tergite of male somewhat trapezoidal, truncate apically. Male terminalia ( Figs. 92– 94 ): margins of epandrium in posterior view parallel, rounded dorsally; surstyli in posterior view roughly forming equilateral triangle, produced at base with short curved process that bears setae, apically as 2 narrow, elongate processes oriented medially with a narrow gap between, lateral prong very elongate, robust, bearing an apical tuft of setulae, the main surstylar process narrow, elongate, length about twice length of lateral prong, process gradually tapered, generally arched.

Type material. The lectotype male of Ephydra prionoptera Thomson , here designated to stabilize and make more universal the use of this name, is labeled “Pata-gonia/Kinb./ Typus /299 77 [pink]/Riksmuseum Stockholm [green]/ LECTOTYPE Ephydra prionoptera Thomson by W. N. Mathis [red, handwritten].” The lectotype (body length 4.0 mm) and two paralectotype males (here designated, same locality data as lectotype) are deposited in the NRS. All specimens of the type series are pinned directly and are slightly moldy. The abdomen of one of the male paralectotypes has been removed and dissected; the structures are in an attached microvial.

The holotype male of Dimecoenia densa Cresson is labeled “Castro. 20–22. xi. 1926. [20–22 Nov 1926]/S. Chile: Chiloe I. F. & M. Edwards. B. M. 1927–63./Ƌ/Holo-TYPE Dimecoenia DENSA E. T. Cresson Jr [dark maroon].” This specimen is in excellent condition (right wing slightly torn), is double-mounted (minute nadel) on a celluloid rectangle, and its abdomen has been removed and dissected; the structures are in an attached microvial (total length before dissection 4.08 mm). Cresson's original description also listed three female paratypes, all presumably in the BMNH with the holotype.

The holotype male of Dimecoenia travassosi Mello and Oliveira is labeled “Santa Cruz, Rio de Janeiro[,] BRASIL [,] Paschoal Robbs VI. [19]90/50.016 IOC.” The holotype is pinned directly, is in good condition, and is deposited in IOC.

Type locality. Argentina. Patagonia (44°S, 68°W).

Additional specimens examined. CHILE. Chiloe: Ancud (41°52.2'S, 73°49.2'W), 20 Jan 1952, L. E. Peña (9♂, 8♀; USNM); Chepu (42°02.2'S, 73°57.9'W), Apr 1968, L. E. Peña (6♂, 3♀; USNM); Dalcahue (42°21.8'S, 73°42.1'W), Feb 1961, L. E. Peña (1♂, 1♀; CNC). Coquimbo: Tilama, El Naranjo (32°05'S, 71°10'W), Oct 1967, L. E. Peña (1♀; USNM); Huaquen (35°07'S, 71°43'W), 26 Jul 1960, L. E. Peña (1♂; CNC). Magellanes: Isla Navarino-Puerto Williams (54°56'S, 67°37'W), 1 Jan 1959, P. G. Kuschel (1♂, 2♀; USNM). Palena: Camping Arrayanes (5 km NW Chaitén; 42°53.8'S, 72°40.1'W; Malaise trap), 21 Jan 1987, C. M. and O. S. Flint (1♂; USNM). Santiago: Llolleo (33°35'S, 71°35'W), M. E. Irwin, E. I. Schlinger (6♂, 7♀; CAS, USNM).

Distribution (Map 21). Neotropical: Argentina (Patagonia), Chile (Chiloe, Coquimbo, Magellanes, Palena, Santiago).

MAP 21. Distribution map for Neoephydra prionoptera (Thomson) .

Remarks. The lectotype male (length 4.0 mm) of Ephydra prionoptera differs from other specimens of this species in that the metallic luster or sheen over much of the dorsum is blackish blue to bluish green. The mesofrons and dorsum of the interfoveal hump are purplish blue; the scutum is blackish blue; and the abdomen is dark blue medially, becoming more greenish laterally. The holotype male of D. densa is a large specimen (4.08 mm) and is considerably more brownish in appearance. The mesofrons is bronzish blue-green; the scutum is mostly brown to blackish brown with some metallic luster; and the abdomen is only slightly metallic, medially, becoming more microtomentose and grayer toward the posterior margin of each tergite.

Figures

FIGURES 92 – 94. Structures of male terminalia of Neoephydra prionoptera (Thomson). (92) epandrium, cerci, surstyli, posterior view; (93) same, lateral view; (94) surstylus, lateral view.