Dasythereva patagonia, 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 : 61-64

Dasythereva patagonia sp. n.

( Figs 5B , 6B , 7–10 , 11B , 12B, D , 13 , 15–16 ) https://zoobank.org/ urn:lsid:zoobank.org:act:11589610-F958-4632-A089-2C2FF871CE97

Common name. Patagonian woolly Stiletto Fly.

Diagnosis. Scale-like setal pile on head and thorax yellowish-tan, admixed black filiform setae sparse; abdominal setae entirely white.

Description. Body length: 8.0– 9.5 mm (male), 9.0– 9.5 mm (female). Head with greyish-brown pubescence, darker on upper frons ( Fig. 5B ); frons with dense, erect and dishevelled pile of lanceolate (scale-like) setae, yellowish-brown dorsally, lighter ventrally on lower frons and parafacial, upper frons also admixed with erect, filiform black setae (longer and denser in male); parafacial with dense yellowish-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 yellowish-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 dark 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), light 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 irregular dishevelled appearance, upper part of pleuron with yellowish suffusion, setae absent on meron and katepisternum, admixed with black, filiform setae on anepisternum; 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 to black; haltere yellowish; wing ( Fig. 12B, D ) 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 setae on tergites 2–5 (some females denuded medially, e.g., Fig. 11B ); segments 6–8 of female predominately with much shorter, erect, black setae. Male genitalia ( Figs 13 , 15 ): Epandrium quadrangular, elongate 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. The species epithet refers to the Patagonian region of South America where this species occurs.

Comments. Dasythereva patagonia sp. n. is distinguished from D. penai sp. n. by the uniform white lanceolate setae on the abdomen and the less-dense pile of black filiform setae on the scutum. This species is known from dune habitats in Argentina and Chile. The type series comprises specimens that were hand-netted or reared from larvae, and consequently they are in good condition. The additional 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: Santa Cruz Province: 2 km S Caleta Olivia [-46.4865, - 67.4881], 10m. 12.xii.1967, E.I. Schlinger, M.E. Irwin, coastal dunes ( MEI1147432 , MNBR).

Paratypes. ARGENTINA: Santa Cruz Province: 20 males, same data as holotype (147433–44, 147449, 153376, 153378, 167945, 167947–9, CSCA, UCCS) ; 4 males, 5 km NW [Comandate Lius] Piedrabuena [-49.9722, -68.9894], 130m, 10.xii.1966, E.I. Schlinger, M.E. Irwin, low dunes [reared] ( MEI147445–7 , 167946 , CSCA) .

Other material examined. ARGENTINA: Chubut Province: 2 males, Arroyo Pescado [-43.0754, -70.8150], 630m, 19.xi.1966, M.E. Irwin, E.I. Schlinger, fine blown dune sand ( MEI147448 , 153380 , CSCA) ; 1 male, 25km S Comodore Rivadavia [-45.9968, -67.5985], hand net on hillside dune, M.E. Irwin , 7.i.2006, 30m ( CSCA) . CHILE: Choapa Province: 2 males, 7 km N. Los Vilos, 9.ii.1989, R. Miller, L. Stange [-31.851, -70.495] ( MEI146229 , 146280 , FSCA) . Copiapo Province: 1 female, Rodillo, 7 km N. Caldera , 2.x.1997, 5 m, dry canyon, M.E. Irwin, D.K. Yeates [-27.0058, -70.7851], [larva sieved form sand] pupated? 15.ii.1998, eclosed? 9.iii.1998 [teneral specimen] ( MEI114569 , CSCA) . Coquimbo Province: 1 female, near Tongoy [-30.25, -71.50], 10.i.1989, B. R. Miller, L.A. Stange, under plants, coastal dunes [reared] ( MEI167934 , FSCA) . Limarí Province: 1 female, Fray Jorge National Park, Quebrada las Vacas , 16.xi.1997, Malaise across damp wash, M.E. Irwin, E.I. Schlinger, 145m [- 30.6710, -71.6421] ( MEI0106338 , CSCA) .

Figures

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 7. Dasythereva patagonia sp. n., adult male, lateral view. Body length: 9.0 mm.

FIGURE 8. Dasythereva patagonia sp. n., adult male, oblique view. Body length: 9.0 mm.

FIGURE 9. Dasythereva patagonia sp. n., adult female, lateral view. Body length: 9.1 mm.

FIGURE 10. Dasythereva patagonia sp. n., adult female, oblique view. Body length: 9.1 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 13. Dasythereva patagonia sp. n., Male genitalia.A. epandrium; B. gonocoxites, ventral view; C. same, lateral view; D. aedeagus, lateral view; E. same, dorsal view. Female genitalia. F. Furca and internal genitalic structures. Scale line: 0.2 mm. Abbreviations: ag, accessory gland; d, distiphallus; da, dorsal apodeme of parameral sheath; ea, ejaculatory apodeme; f, furca; ga, gonocoxal apodeme; gs, gonostylus; igp, inner gonocoxal process; ogp, outer gonocoxal process; s, spermatheca; sd, spermathecal duct; ss, spermathecal sac; ssd, spermathecal sac duct; vl, ventral lobe.

FIGURE 15. Dasythereva patagonia sp. n., genitalia. A. epandrium and tergite 8; B. gonocoxites, ventral view; C. aedeagus, lateral view; D. same, dorsal view; E. gonocoxites, lateral view. Scale line: 0.2 mm.

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