Dasythereva penai, Irwin & Winterton, 2020

Irwin, Michael E. & Winterton, Shaun L., 2020, A new genus of therevine stiletto flies from South America (Diptera: Therevidae), Zootaxa 4838 (1), pp. 52-70 : 56-59

Dasythereva penai sp. n.

( Figs 1–4 , 5A , 6A , 11A , 12A, C , 14 , 16 ) https://zoobank.org/ urn:lsid:zoobank.org:act:03BFAE2D-A1B1-451E-AEE1-F71F38649DB2

Common name. Peña’s Woolly Stiletto Fly

Diagnosis. Scale-like setal pile on head and thorax whitish-tan, admixed with black, filiform setae; abdominal setae white with black medial and lateral stripes.

Description. Body length: 9.0–11.0 mm (male), 8.5–9.5 mm (female). Head with grey-silver pubescence, darker on upper frons ( Fig. 5A ); frons with dense, erect and dishevelled pile of lanceolate (scale-like) setae, light brown dorsally, predominantly white ventrally on lower frons and parafacial ( Fig. 5A ), upper frons also admixed with erect, filiform black setae (longer and denser in male); parafacial with dense white setal pile; occiput with sparse silver pubescence, black macrosetae admixed with erect lanceolate setae, light brown dorsally, whiter laterally to gena; gena with dense white setal pile composed of admixed lanceolate and filiform setae, small patch of dark setae ventrally, adjacent to parafacial; labellum dark with erect white setal pile; palpus with dense white setal pile; antenna dark, scape with grey-silver pubescence and with large black setae admixed with smaller, white lanceolate setae; pedicel with grey-silver pubescence and band of small darks setae; flagellum dark brown; thorax ground colour black with sparse silver pubescence on pleuron, brown on scutum and scutellum; scutum and scutellum with recumbent (directed posteriorly), yellowish-brown, lanceolate setae admixed with longer, erect, black, filiform setae (longer in male); scutal macrosetae black; pleuron with dense pile of elongate, white, lanceolate setae with dishevelled appearance (upper part of pleuron yellowish suffusion in female), absent on meron and katepisternum, admixed with black, filiform setae on anepisternum and katatergite; coxae and femora black with elongate lanceolate and filiform setae; femora with shorter, yellowish and adpressed, lanceolate setae dorsally, longer and erect lanceolate setae ventrally admixed with black and white filiform setae; legs with all macrosetae black and relatively elongate; tibiae dark yellow to brown, darker apically; tarsi brown with black suffusion distally; haltere yellowishbrown; wing ( Fig. 12A, C ) whitish translucent with leathery appearance, venation brown with yellowish suffusion on membrane along veins, brown markings on veins and cross-veins; infuscation in centre of most wing cells, especially towards wing margin; wing base with black setae as well as patch of short, white lanceolate setae; abdomen ground colour black with sparse grey to brown pubescence, admixed with extensive matted and dishevelled, white, lanceolate setal pile, setal longer laterally, black stripe of setae medially and laterally on tergites 2–5; segments 6–8 of female predominately with much shorter, erect, black setae; terminalia with erect black setal pile. Male genitalia ( Fig. 14 ): Epandrium quadrangular, rounded processes posterolaterally, strong black setae in posterior half, longer laterally, shorter and denser posterolaterally; cerci elongate; gonocoxite broadly rounded anteriorly, quadrangular posteriorly with small outer gonocoxal process and smaller process posteroventrally; large, erect setae longer laterally and posteroventrally on processes; gonocoxal apodeme very small; hypandrium narrow and band-like; ventral lobe narrow and truncate, inner gonocoxal apodeme short, truncated apically with few setae; gonostylus robust with strong keel and acuminate apex; aedeagus with dorsal apodeme of parameral sheath large, subtriangular, ventral apodeme narrow, distiphallus narrow and recurved ventrally; ejaculatory apodeme narrow, spatulate apically. Female terminalia as per genus description.

Etymology. This species is named in honour of the noted Chilean field entomologist, the late Luis (Lucho) Peña.

Comments. Dasythereva penai sp. n. is easily distinguished from D. patagonia sp. n. by the black stripes of lanceolate setae on the abdomen and the denser pile of black filiform setae on the scutum. This species is known from sandy habitats (e.g., dunes, dry sandy river beds, etc.) in Argentina and Chile. It has been reared from larvae collected by sifting sand around the base of vegetation. The type series from Argentina comprises specimens that were hand-netted or reared from larvae, and consequently they are in good condition. The specimens from Chile were collected into ethanol-filled Malaise traps before being dried and pinned. Unfortunately, most of these specimens are almost completely denuded and are lacking much of the diagnostic erect setal pile. While they are confirmed to belong to this species they have been included as additional material due to their poor condition rather than being included in the type series.

Type material. Holotype male, ARGENTINA: Neuquén Province: Neuquén, 10.2 km S Zapala [-38.9905, -70.0969], 1020 m, 17.xii.1966, E.I. Schlinger, M.E. Irwin ( MEI028441 , MNBR).

Paratypes. ARGENTINA: Neuquén Province: 7 males, 5 females, same data as holotype ( MEI147455– 60 , 167935–6 , 167952–5 , CSCA) . Santa Cruz Province: 2 females, 5 km NW [Comandate Lius] Piedrabuena [-49.9722, -68.9894], 130 m, 10.xii.1966, E.I. Schlinger, M.E. Irwin, low dunes [reared] ( MEI147454 , 167937 , CSCA) ; 11 females, 2 km S Caleta Olivia [-46.4865, -67.4881], 10 m . 12.xii.1967, E.I. Schlinger, M.E. Irwin, coastal dunes ( MEI147450–53 , 153375 , 153377 , 167938–41 , 167956 , CSCA, UCCS) .

Other material examined. CHILE: Atacama Province: 2 males, 1 female, 5 km S San Pedro de Atacama Solor [-22.944, -68.175], 2414 m, M.E. Irwin, F.D. Parker ( CSCA) ; one female, 13 km E San Pedro de Atacama [-22.9225, -68.0758], 15.xi–21.xii.2003, 2568 m, Malaise in wide wash with shrubs, M.E. Irwin, F.D. Parker ( CSCA) . Copiapó Province: 21 males, 11 females, 125 km SE Copiapó, Fundo La Semilla [-28.2506, -69.741], 2028 m, Malaise in ravine, alluvium in river, various dates (17.xi–19.xii.2003), M.E. Irwin, F.D. Parker ( CSCA, UCCS) . Coquimbo Province: 2 males, Elqui Quebrada Las Mulas, nr. El Indio Mine [-30.226, -70.492], 3100 m, 19.i–23.ii.1993, Malaise trap, H. Vasques C. ( MEI147463 , 106984 , CSCA) . Limarí Province: 1 female, Fray Jorge National Park, Quebrada las Vacas , 2 km NW Admin, 3.xi.1997, Malaise across damp wash, M.E. Irwin, E.I. Schlinger, 550 ft. [168m], [-30.6710, -71.6421] ( MEI106990 , CSCA) .

Figures

FIGURE 1. Dasythereva penai sp. n., adult male, lateral view. Body length: 9.5 mm.

FIGURE 2. Dasythereva penai sp. n., adult male, oblique view. Body length: 9.5 mm.

FIGURE 3. Dasythereva penai sp. n., adult female, lateral view. Body length: 9.2 mm.

FIGURE 4. Dasythereva penai sp. n., adult female, oblique view. Body length: 9.2 mm.

FIGURE 5. Dasythereva gen. n., adult males, anterior view. A. D. penai sp. n.; B. D. patagonia sp. n.

FIGURE 6. Dasythereva gen. n., adult males, dorsal view. A. D. penai sp. n., body length: 9.5 mm; B. D. patagonia sp. n., body length: 9.0 mm.

FIGURE 11. Dasythereva gen. n., adult females, dorsal view. A. D. penai sp. n., body length: 9.2 mm; B. D. patagonia sp. n., body length: 9.1 mm.

FIGURE 12. Dasythereva gen. n., wings. A. D. penai sp. n., male; B. D. patagonia sp. n., male; C. D. penai sp. n., female; B. D. patagonia sp. n., female.

FIGURE 14. Dasythereva penai sp. n., genitalia. A. epandrium; B. gonocoxites, lateral view; C. aedeagus, lateral view; D. gonocoxites, ventral view E. aedeagus, ventral view. Scale line: 0.2 mm.

FIGURE 16. Distribution of Dasythereva spp. collecting records throughout Argentina and Chile.