Aspistomella schnusei Kameneva & V. Korneyev, 2024

Kovac, Damir, Kameneva, Elena P., Korneyev, Severyn V., Araújo, Alexandre Santos, Savaris, Marcoandre, Smit, John T., Schneider, Alexander, Schreiber, Robert & Korneyev, Valery A., 2024, Revision of the Aspistomella group of genera (Diptera: Ulidiidae: Pterocallinae: Lipsanini), Zootaxa 5530 (1), pp. 1-117 : 66-68

Aspistomella schnusei Kameneva & V. Korneyev , sp. nov.

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Figs 6 B , 39

Material examined. Type. Holotype ♀: “ Peru — Mapiri / 16.I.03 / Sarampioni 700 m ” [Schnuse leg.], “ Paraphyola ”, “Euxestinae / Präp. 3” [W. Hennig’s handwritten labels] ( SMTD).

Diagnosis. Aspistomella schnusei distantly reminds A. angustifrons , A. crucifera , A. garleppi , A. obliqua , and A. terezae in its narrow wings, and A. angustifrons , A. garleppi , and A. pachitea in its narrow frons, but it differs from all of them in that the epistome is conspicuously produced anteriorly and the wing is widely hyaline with narrow bands apically (in the epistome is only weakly developed anteriorly and the wing is widely brown with hyaline incisions apically). It also differs from the other species of the Aspistomella group of genera by its matt, finely and densely microtrichose abdominal tergites.

Description. Female. Head ( Figs 39 A–D ) ratio (length: height: width) = 1: 1.46: 1.85; frons, face above transverse fold, parafacial, and gena reddish to yellowish brown, epistome and occiput mostly black. Frons narrow, slightly narrowed posteriorly, 1.05× as long (from lunule to anterior ocellus) or 1.65× (from lunule to inner vertical seta) as wide (at lunule), with almost matt brown or black ocellar triangle and brown vertical plates; orbits, vertex, gena and occiput silver-white microtrichose; parafacial narrow, reddish-yellow, sparsely white microtrichose. Frontal plates with 9–10 parafrontal setulae, 6–8 frontal setae on each side; frontal vitta sparsely whitish microtrichose, with 3–5 interfrontal setae on each side ( Fig. 39 C ). Eye 2× higher than long, its posterior margin distinctly concave ( Fig. 39 D ). Face white microtrichose (above epistome); epistome brown, sparsely white microtrichose, with metallic bluish sheen. Clypeus yellow, white microtrichose, subshining, less than 1/3 as high as epistome. Gena brownish yellow, with long genal seta and 4–5 additional long peristomal setae anterior of it, as long as genal seta. Occiput black, with cyan metallic sheen, greyish microtrichose.

Antenna yellow; scape and pedicel with black setulae; postpedicel and arista missing in the holotype.

Mouthparts brown to black, prementum black, sparsely microtrichose. Palp yellow, as described for A. angustifrons . Most setae missing in the holotype, except one very long inner vertical seta 17× longer than outer vertical seta; the latter 2× longer than postocular setae and 0.5× longer than postocellar seta. Alveolae of posterior orbital and ocellar setae almost as big as alveola of inner vertical seta, so these setae are supposed to be subequal to the latter one. Alveolae of ocellar setae strongly approxamated and touching.

Thorax ( Figs 39 A, B, E ) brown to black, silvery subshining, on pleura with suberect white microtrichia not hiding underlying cuticle. Mesonotal scutum 1.4–1.5× longer than wide; matt, shagreened and covered with curled white microtrichia; black setulose, with 7–8 rows of setulae between rows of dorsocentral setulae; acrostichal prescutellar seta absent. Other setae as described for the genus, black. Scutellum dorsally rather flattened, brown, silvery subshining, microtrichose, without setulae. Subscutellum and mediotergite black, subshining, sparsely microtrichose. Pleura smooth, shining, sparsely white microtrichose, with cyan sheen.

Wing ( Fig. 6 B ) 3.9 mm long (♀), 3.8× longer than wide; basicostal cell hyaline; costal cell straight, 5.1× longer than wide, brown in basal 1/6 of its length; pterostigma entirely brown, narrowly triangular, 3.5× longer than wide, vein R 1 bare, ending proximally of crossvein r-m level; vein R 2+3 slightly arcuate in basal half, straight at apex. Crossvein r-m distal to mid-length of cell dm. Cell r 4+5 5.7× longer than wide. Cell m 1 narrowly triangular; ultimate section of M 1 3.3× longer than crossvein dm-m and 1.8× longer than penultimate section, posteriorly conspicuously dipping at middle. Vein CuA Z-shaped, forming moderately short posteroapical lobe of cell cua along vein CuP, 1.2× longer than its anterior shoulder. Wing pattern with short subbasal crossband from humeral vein through cell cua into alula, entirely brown pterostigma, narrow brown band crossing cell r 1 posterior of it and very large brown mark posterior of it in cell br and basal halves of cells dm and cua 1 proximally of crossvein r-m, leaving bases of these cells and cell r 2+3 at radial fork hyaline; inconspicuous dark mark in cells r 1 and r 2+3 distally or r-m level; apical half of wing mostly hyaline, with oblique narrow brown band from subapical part of cell r 2+3 through oblique vein dm-m and faint band along apical parts of cells r 4+5 and m 1 leaving very apex of wing hyaline ( Fig. 6 B ). Cell cup and anal lobe half as wide as cell cua. Alula 4× longer than wide, grey. Calypters white, with white cilia. Halter yellow.

Legs ( Fig. 12 ) with fore coxa mostly black, except yellow mesal and distal 1/6, densely white microtrichose; mid and hind coxae yellow, as well as all trochaners and tarsi; femora black in basal 0.8–0.9, tibiae black in basal 0.6–0.8, apically yellow, black setose and setulose. Fore femur uniformly setulose, without strong erected setae. Mid femur anteriorly with short suberect setulae; mid tibia ventrally with single spur-like seta 3.8× longer than tibia width. Hind femur without dorsal setae.

Abdomen matt black, tergites fine shagreened, black setulose; tergite 5 shagreened, subshining; oviscape sparsely white microtrichose and black setulose, shining.

Male: not known.

Female terminalia (not dissected): aculeus with ovoid, long-setulose cercal unit (partly exposed).

Etymology. The species is named in honour of Karl August Wilhelm Schnuse (1850–1909), a German entomologist, who collected the type specimen and many other specimens of the species mentioned in this paper.

Remarks. The left wing of the holotype has been removed (obviously by W. Hennig in the late 1930s during the preparation of the volumes of “Die Fliegen der Palaearktischen Region). At that time he was working with the picture-winged flies and illustrated most of his monographs with wing photographs; only a few slides were in the MNKB, but certainly not of the South American Ulidiidae . He has never described this specimen or used the photograph of its wing elsewhere. Several specimens, apparently borrowed from the Schnuse collection, were found among unsorted material at the SDEI, where Hennig worked in the late 1930s.

We tentatively place this species in Aspistomella , based on distant similarity to the species previously assigned to Paraphyola , and transferred here. As the male genitalia are unknown, its relationships to the other taxa in this group of genera remain rather unclear. It differs from all the species assigned here in that the abdominal tergites are matt and densely covered with dense rows of very fine and short microtrichia (shiny and sparsely microtrichose in most other species of the group).

Figures

FIGURE 6. Aspistomella, wing. A, A. sachavaca sp. nov.; B, A. schnusei sp. nov.; C, A. angustifrons (Hendel); D, A. garleppi sp. nov.; E, A. crucifera (Hendel); F, A. quinquincisa sp. nov.; G, A. teresensis sp. nov.; H, A. obliqua sp. nov. Abbreviations: C—costal vein; c—costal cell; M1—first branch of media; m1—first medial cell; ptstg—pterostigma; r1—first radial cell; rm—radial-medial crossvein. Scale bar: 1 mm.

FIGURE 12. Aspistomella angustifrons (Hendel) ♀. A, abdomen, ventral; B, apex of aculeus; C, spermathecae.

FIGURE 39. Aspistomella schnusei sp. nov., holotype ♀ (SDEI). A, habitus, right; B, same, left; C, head, anterior; D, same, left; E, mesonotum, dorsal; F, abdominal tergites 1–3, dorsal; G, abdominal tergites 4–7, dorsal; H, labels.