Pachyrrhiza argentata Oldroyd

Irwin, Michael E. & Winterton, Shaun L., 2021, Revision of the Patagonian stiletto fly genus Pachyrrhiza Philippi (Therevidae Agapophytinae), Zootaxa 4975 (2), pp. 273-305 : 277-278

Pachyrrhiza argentata Oldroyd

( Figs 4–8 , 30A, E , 31E , 33A , 35 )

Pachyrrhiza argentata Oldroyd, 1968: 383 — Webb et al. (2013: 15) [catalogue].

Diagnosis. Parafacial with distinct patch of black setae adjacent to gena; hind femur with one or two subapical anteroventral macrosetae; prosternum with setae present or absent; wing mottled; male abdomen with silver velutum pubescence present; mid and hind coxal pile absent on posterior surface (rarely present on mid coxa).

Redescription. Body length: 5.0– 6.8 mm. Head with frontal pubescence light brown dorsally, silver around antennal base, dark brown band above antenna in female; parafacial with small dark patch of setae adjacent to gena; genal setae pale; male frontal vestiture consisting of patch of short setae above antenna, shorter than setae on scape; female frontal vestiture consisting of scattered dark, short to moderate length setae; occiput grey with brown pubescence; antennal scape length slightly longer than maximum width, brown, overlain with grey pubescence, numerous erect, large black macrosetae; flagellum brown with grey pubescence. Thorax with scutum pubescent grey with broken, dark brown stripes, some setal bases dark brown, two dark medial stripes anteriorly joining posteriorly, lateral stripes irregular, vestiture as numerous erect black setae, longer and denser in male; prosternum with setae present or absent medially; pleuron dark, overlain with grey pubescence; katatergite setae all white; posterior surface of mid coxa without setae, rarely with a few white setae present; femora dark brown (usually males) to dark yellow, suffused with brown-black dorsally (female), short dark setae admixed with elongate pale setae ventrally; hind femur with 1 or 2 subapical anteroventral macrosetae; tibiae yellow, dark grey-brown apically; tarsi dark yellow with apices brown; wing mottled dark infuscate, fenestrate in some cells; costal cell brown infuscate basally, yellow infuscate distally; scutal chaetotaxy (macrosetae pairs): notopleural 3, supra alar 1, post alar 1, dorsocentral 3–5, scutellar 2. Abdomen of male abdomen base colour dark brown dorsally, yellow laterally, silver velutum on tergites 2–7, male vestiture mostly elongate pale setae, denser laterally; terminalia dark yellow; female abdominal markings mostly dark brown, posterior margin pale, broader laterally, intersegmental membrane distinctly pale coloured, well defined. Male and female genitalia as per genus description except male with epandrium with dark medial stripe; aedeagus with distiphallus narrow apically.

Comments. Pachyrrhiza argentata is easily distinguished from other Pachyrrhiza species by the mottled wing pattern, 1–2 subapical anteroventral macrosetae on the hind femur and male abdomen with silver velutum. It appears closely related to P. parargentata sp. n. and P. argentatoides sp. n. and while their respective distributions overlap, P. argentata is more widely distributed along the Argentinian eastern slopes of the southern Andes mountain range ( Fig. 35 ).

Type material. Holotype male, ARGENTINA: Río Negro Province: San Carlos de Bariloche, San Ramon [-41.1373, -71.2482], 22.iv.1966, [reared] pupated 14.xi.1966, emerged 8.xii.1966 ( NHM) . Paratypes. ARGENTINA: Río Negro Province: 6 females, 2 males, same data as holotype [various dates, also reared] ( NHM). Neuquen Province: 1 male, Estancia Fortin Chacabuco [approximated as -41.0044, -71.1638], 3.iv.1966, [reared] pupated 25.xi.1966, emerged 23.xii.1966 ( NHM). (Types examined)

Other material examined. ARGENTINA: Chubut Province: 2 females, El Maitén [-42.0517, -71.1667], 18.XI.1966, L. Pena ( MEI167328 , 167352 ; CSCA) ; 1 male, Esquel [-42.9099, -71.2849], 590 m, hand netted on walkway ( CSCA) ; 7 males, 4 females, Cholila, Chacra of Stephen Bussey, Malaise in steep gorge [-42.4503, -71.45], 23–31.XII.2005, M.E. Irwin, 560 m ( CSCA) ; 2 males, 13 females, Sierra de San Berardo, 57 km W. Sarmiento [- 45.4555, -69.682], 540 m, Malaise in small wash, 21–31.XII.2005, M.E. Irwin ( CSCA) ; 2 males, 1 female, Parque Nacional Alerces, 530 m, Lago Futalaufquen, nr. Hosteria Quime Quipan [-42.8611, -71.6026], 22.XII.2005, Malaise, Nothophagus, M.E. Irwin ( CSCA) . Mendoza Province: 1 male, 1 female, Ref. Gral. Alvarado [approximated as -32.895, -68.842], Col. Duret, 13.XII.53 ( MNHN) . Rio Negro Province: 45 males, 57 females, Nahuel Huapi National Park, 2 km S. Rincon Chico, Malaise in Patagonian steppe [-41.0025, -71.1268], 24–31.XII.2005, M.E. Irwin, 890 m ( CSCA) . Neuquen Province: 2 males, Parque Nacional Lanin, 4 km E. Estancia Los Helechos at Arroyo Blanco [-39.7836, -71.0345], Malaise in steppe prairie, 25.XII.2005 – 2.I.2006, M.E. Irwin, 990 m ( CSCA) . 12 males, 20 females, 9 km W. highway 23 on highway 60, Estancia Mamuil Malal Lolen [-39.7555, -71.1248], Malaise in sand prairie, 26.XII.2005 – 3.I.2006, M.E. Irwin, 890 m ( CSCA) ; 24 females, Dept. Collon Cura, 54 km S. La Rinconada, Malaise in dry wash [-40.4038, -70.6538], 25–27.XII.2005, M.E. Irwin, 670 m ( CSCA) . CHILE: Aysén Province: 1 male, 1 female, 5.8 km W. Chile Chico [-46.5483, -71.8047], 450 m, 23.XI.1966, E.I. Schlinger, M.E. Irwin ( MEI167363 , 167323 ; CSCA) ; 7 males, 2 females, 8 km W. Chile Chico [-46.5517, -71.8355], 540 m, 22.XI.1966, E.I. Schlinger, M.E. Irwin ( MEI167366–7 , 167371 , 167373–6 , 167327 , 167329 ; CSCA) . Los Rios Province: 1 female, Panguipulli [approximated as -39.638, -72.335], Jan.1945 ( MEI167474 ; CSCA) . Malleco Province: 1 female, Marimenuco [approximated as -38.712, -71.107], 10.XII.1959, L.E. Peña, 1100 m ( MEI167460 ; CSCA) .

Figures

FIGURE 4. Pachyrrhiza argentata Oldroyd, 1968, holotype male with pupal case, oblique view.

FIGURE 5. Pachyrrhiza argentata Oldroyd, 1968, adult male, oblique view.

FIGURE 6. Pachyrrhiza argentata Oldroyd, 1968, adult male, lateral view.

FIGURE 7. Pachyrrhiza argentata Oldroyd, 1968, adult female, oblique view.

FIGURE 8. Pachyrrhiza argentata Oldroyd, 1968, adult female, lateral view.

FIGURE 30. Pachyrrhiza spp. heads, oblique view. A. P. argentata Oldroyd, 1968, male; B. P. subpictipennis sp. n., male; C. P. argentatoides sp. n., male; D. P. pictipennis Philippi, 1865, female; E. P. argentata Oldroyd, 1968, female; F. P. elegantissima sp. n., female; G. P. pictipennis Philippi, 1865, male; H. P. parargentata sp. n., male; I. P. argentatoides sp. n., female; J. P. subpictipennis sp. n., female; K. P. elegantissima sp. n., male.

FIGURE 31. Pachyrrhiza spp. wings. A. P. subpictipennis sp. n.; B. P. argentatoides sp. n.; C. P. parargentata sp. n.; D. P. elegantissima sp. n.; E. P. argentata Oldroyd, 1968; F. P. pictipennis Philippi, 1865.

FIGURE 33. Pachyrrhiza spp. male genitalia, gonocoxites with aedeagus in situ, ventral view (left) and epandrium (right). A. P. argentata Oldroyd, 1968; B. P. argentatoides sp. n.; C. P. elegantissima sp. n. Scale line: 0.2 mm.

FIGURE 35. Distribution of Pachyrrhiza species in Chile and Argentina.