Neohemigaster tetralineata 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 : 280

Neohemigaster tetralineata Galinskaya & Shatalkin sp. nov.

( Fig. 8 )

Type material. Holotype 3: “ Formosa, coll. Oldenberg, Sauter R.” (SDEI). Paratypes. 53: “ Formosa, coll. Oldenberg, Sauter R.” (SDEI).

Diagnosis. The new species belongs to the species group including N. ornata and N. angustifrons sp.n. All the three species are similar in the structure of stigmatal band, which not reachs to r-m vein. The new species differs from N. ornata in having scutellum with broad yellow bordering and in possessing abdominal tergites with yellow bordering on posterior margin (by these characters N. tetralineata sp. nov. is similar to N. flavopicta Hennig ). The new species is characterized by the entire prediscal band, connected with the mark on r-m vein (in N. ornata this band broken into spots). N. tetralineata sp. nov. has discal band bifurcated in r4+5 cell and reconnected in m cell. It should be noted that Hennig (1940, Taf. 24, Fig. 6 ) gave a photo of the wing with poorly printed wing pattern. In this paper we give a figure, made from the wing slide of N. ornata type specimen ( Fig. 4 d). Note also, that Hennig (1940) in description of N. ornata did not point the presence of spot between antenna base and eye, which is present in N. tetralineata . N. angustifrons differs from N. tetralineata sp. nov. by the absence of medial facial brown spots; blackish-brown marking on scutellum disk broken into two spots; ventral yellow spot on anepisternum stretching posteriorly over anepisternum border, comes up to anepimeron, apical part of katepisternum and katepimeron.

Description of the holotype. Male. Head yellow ( Fig. 8 c,d). Head ratio (length:height:width) = 1:1.85:2.2. Frons: relatively wide, almost as wide as eye, yellow, with one pair of black round spots, widely separated from each other and narrowly separated from eye margin; narrow brown median stripe stretching from black ocellar triangle to posterior margin of above-mentioned spots; in addition, in the direction of eye margin stretching two lateral stripes, turn 90 before reaching eye margin. Eyes bare, about 1.6 times as high as wide. Gena about 0.28 times as high as eye. Lunule yellow, black setulose. Parafacial very narrow at antennal groove level; smooth, with brown stroke spot between antennal base and eye margin. Facial ridge broad, yellow; its ventral part with a group of black hairs not in a linear series. Face yellow with black middle spot and two black spots in the point of bend of frontogenal suture; these lateral spots continue across facial ridge up to ptilinal fissure. Mouth margin with triangular middle brown spot and two stroke lateral brown spots. Occiput black in dorsal half and yellow in ventral half. Brown spot in ventral part of occiput at the eye margin. Antenna yellowish-brown. First flagellomere narrowly yellow at the base, about 1.2 times as long as wide. Arista moderately long haired, its feathering about 0.4 times as wide as first flagellomere. Palp yellow, covered with blackish setulae. Proboscis yellow; prementum densely covered with yellow setulae.

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

Thorax mostly black ( Fig. 8 b). Postpronotal lobe yellow. Mesonotum (as in N. eurysterna ) with 5 longitudinal yellow stripes. Three of them (median and pair of lateral stripes) reaching from its anterior margin (at the level of middle of postpronotal lobes) to scutellum. Two marginal mesonotal stripes starting from transverse suture merging with long lateral stripes of scutellum. Two transverse stripes in postsutural area of scutum between long lateral stripes. Yellow stripes at dorsal margin and in ventral part of anepisternum reaching its posterior margin ( Fig. 8 a). Scutellum black with yellow bording.

Setae: 1 pprn, 2 npl, 1 psut spal, 1 very strong pal and 1 very strong ial, 1 weak dc; 3 rather stout sctl at posterolateral corner and posterior margin; 1 anepst; kepst lacking.

Legs. Femora brownish-black except yellow knees. Tibiae with a middle yellow ring and broad yellow bases. Tarsomeres 1–3 yellowish-white, tarsomere 4 brownish-yellow, tarsomere 5 brown.

Wing hyaline, with numerous brownish-grey irregular spots ( Fig. 8 e): prediscal band reach dark marking at rm vein; discal band bifurcated at cell r4+5 and reconnected in medial cell. Stem R vein without dorsal setulae. Vein R4+5 setulose dorsally on 9/10 of its length, and bare ventrally. Halter yellow. Calypters white.

Abdomen shining black. Tergites 2–5 narrowly yellow at posterior margin.

Body length 5.0 mm. Wing length 5.0 mm.

Female not known.

Etymology. The species name is derived from the Greek “tetra”, four, and Latin “lineatus”, striped, because of 4 transversal bands in cell r4+5.

Figures

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 6. Neohemigaster eurysterna Hendel, 1914, male; a—habitus, lateral view, b—head and thorax, dorsal view; chead, lateral view; d—head, anterior view; e—wing.

FIGURE 8. Neohemigaster tetralineata sp. nov., male holotype; a—habitus, lateral view, b—head and thorax, dorsal view; c—head, lateral view; d—head, anterior view; e—wing.