Pterogenia tenebrica Galinskaya & Shatalkin

Galinskaya, Tatiana V. & Shatalkin, Anatole I., 2013, Neohemigaster Malloch, 1939 and Pterogenia Bigot, 1859 (Diptera: Platystomatidae) from eastern Eurasia, with the description of four new species, Zootaxa 3666 (2), pp. 267-285 : 270-274

Pterogenia tenebrica Galinskaya & Shatalkin sp. nov.

( Fig. 3 )

Type material. Holotype Ƥ: “ Formosa, Sokutsu, VI 1912, Sauter H.” (SDEI). Paratypes. 2 Ƥ: “ Formosa, Sokutsu, VI 1912, Sauter H.” (SDEI); 3: “ Formosa, Sokutsu, VI 1912, Sauter H.” with handwritten label “ Pterogenia luctuosa det. Hendel” (SDEI); 3: “ Formosa, coll. Oldenberg, Sauter R.” (SDEI).

Diagnosis. The new species is very similar to P. luctuosa . Hendel (1914b, S. 308) described Pterogenia luctuosa based on a single male, which, as he mentioned in description, has a label and depositary: 13 aus Formosa, Kosempo (leg. H.Sauter), im Deutsch. Ent. Nat. Museum. He meant Deutschen Entomologischen National-Museum zu Berlin, later Deutsches Entomologisches Institut (Eberswalde, DEI), now Senckenberg Deutsches Entomologisches Institut Müncheberg. In SDEI, due to kindly help of Dr. Frank Menzel, all the Pterogenia material was looked through. A type specimen of Pterogenia luctuosa is absent there. It also was not listed by Rohlfien and Ewald (1972). Based on our own search and information from Dr. Joachim Ziegler the type specimen is also absent in Museum für Naturkunde der Humboldt-Universität zu Berlin. Dr. Peter Sehnal from Naturhistorisches Museum Wien (NHMW) kindly inform us, that type of Pterogenia luctuosa is absent in the Hendel’s collection in Vienna; however there are non-type specimens of Pterogenia luctuosa with label "Sokutsu Formosa " (2 3, 2 Ƥ).

Due to absence of the type, in the diagnostics of Pterogenia luctuosa we follow Hendel’s (1914b) description. P. tenebrica sp.nov. differs from P. l u c t u o s a in having the brown spot between antennal base and eye and by lunule dark brown (lunule yellow in P. luctuosa ). In wing color pattern the new species differs from P. luctuosa by prediscal wing band (short transverse band beginning from R1 apex) merging with stigmatal wing band (broad band beginning from Sc apex) in r4+5 cell ( Fig. 3 e). In P. l u c t u o s a prediscal band does not reach stigmatal one ( Fig. 5 e). P. luctuosa and P. tenebrica sp.nov. may be confused with P. hamifera Frey from Burma. The transverse wing band beginning from R2+3 apex is contiguous in P. hamifera ( Fig. 4 a), but broken into separate spots in P. l u c t u o s a and P. tenebrica .

We marked female as a holotype in this case, because genitals have never been used to separate species in these genera. All species are well separated by characters of external morphology (in which males and females do not differ). McAlpine, describing Platystomatidae , often marked female as a holotype in the presence of males in type series.

Description of the holotype. Female. Head black ( Figs 3 c,d). Head ratio (length:height:width) = 1:2.0:2.5. Frons: relatively wide, 0.4 times as wide as head and 1.3 times as wide as eye; black, yellow anteriorly and narrowly yellow behind ocellar triangle; with pair of middle yellow transverse stripes, widely separated from each other and merging with eye margin; evenly covered with short and thin black setulae. Black spot between antenna base and eye. Eye bare. Eye 1.8 times as high as wide. Gena 0.3 times as high as eye. Lunule dark brown, black setulose. Parafacial very wide, wrinkled, brownish-yellow. Facial ridge very narrow, yellow, its ventral part with very short black setulae. Margin of peristomal cavity with a pair of lateral light brown spots. Occiput dark brown. Scape dark brown. Pedicel dark brown, yellowish in apical third. First flagellomere blackish-brown, short, 1.3 times as long as wide. Arista dark brown, yellow in base, covered by short hairs. Arista feathering as wide as or slightly longer than thickness of arista base. Palp and proboscis black.

Setae: 1 o vt, 1 i vt; orb, oc and poc absent; gn well-developed, black.

Thorax and scutellum completely black ( Fig. 3 b). Anepisternum with stripe of goldish setulae at ventral margin ( Fig. 3 a).

Setae: 1 pprn, 1 npl, 1 psut spal, 1 very strong pal and ial, 1 weak dc; 6 pairs of rather stout sctl at its posterolateral corner and posterior margin; 1 anepst; kepst lacking.

Legs. Femora and tibiae black. Tarsomeres 1–3 yellowish-white, tarsomeres 4–5 brown.

Wing hyaline, with numerous brownish-grey bands and irregular spots ( Fig. 3 e); short transverse prediscal band merge with stigmatal band. Stem R vein with dorsal black setulae. Vein R1 setulose dorsally from base to apex. Vein R4+5 setulose dorsally on 9/10 of its length, and bare ventrally. Haltere yellow with brownish knob. Calypters brown.

Abdomen black.

Body length 5.4 mm. Wing length 5.3 mm.

Male similar to female.

Etymology. The species name is based on the Latin “tenebricus”, dark, gloomy; because of its uniformly dark appearance.

Figures

FIGURE 3. Pterogenia tenebrica sp. nov., female holotype; a—habitus, lateral view, b—head and thorax, dorsal view; chead, lateral view; d—head, anterior view; e—wing.

FIGURE 4. a— Pterogenia hamifera Frey, 1930, wing (from Frey’s figure 3, Taf. 1); b— Neohemigaster minuspicta Hennig, 1940, wing (Typus); c— Neohemigaster flavopicta Hennig, 1940, wing (Typus); d— Neohemigaster ornata Hennig, 1940, wing (Typus).

FIGURE 5. Pterogenia luctuosa Hendel, 1914, male; a—habitus, lateral view, b—head and thorax, dorsal view; c—head, lateral view; d—head, anterior view; e—wing.