Pachyrrhiza subpictipennis, Irwin & Winterton, 2021

Irwin, Michael E. & Winterton, Shaun L., 2021, Revision of the Patagonian stiletto fly genus Pachyrrhiza Philippi (Therevidae Agapophytinae), Zootaxa 4975 (2), pp. 273-305 : 294-295

Pachyrrhiza subpictipennis sp. n.

( Figs 1 , 26–29 , 30B, J , 31A , 34C , 35 )

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Diagnosis. Parafacial with patch of black setae adjacent to gena; hind femur with 3–6 anteroventral macrosetae along segment length; prosternum with setae medially; wing mottled infuscate; abdomen brown, yellow laterally, male without silver velutum pubescence; mid coxa without setae on posterior surface; femora yellow to brown.

Description. Body length: 5.8–8.2 mm. Head with frons light brown prubescent, silver around antennal base, setae dark, small patch similar length to scape setae above antenna in male, female vestiture distributed more widely over frons; occiput brown to grey pubescent; parafacial setae as small dark patch adjacent to gena; genal setae pale; antennal scape length twice maximum width, brown (male) or dark yellow with brown suffusion dorsally (female), overlain with grey pubescence admixed with numerous erect, large, black setae; flagellum brown with grey pubescence. Thorax with scutum pubescence mostly grey-tan with few brown markings (more in female), narrow dark medial stripe posteriorly, lateral stripes intermittent, setae on scutum and scutellum scattered and very short (female) or with numerous elongate fine setae, denser anteriorly (male); pleuron with dense silver-grey pubescence; katatergite setae variable, from uniform pale, admixed pale and dark, or uniform dark setae; prosternum with pale setal pile medially; mid coxa without setae on posterior surface; femora dark brown, or dark yellow with brown-black suffusion dorsally, short dark setae admixed with longer pale setae, denser ventrally; hind femur with 3–6 (sometimes more) anteroventral macrosetae along entire length; tibiae yellow, dark grey-brown apically; tarsi dark yellow with apices brown; wing extensively mottled infuscate, fenestrate in most cells, small fenestrations basally in medial cells; costal cell brown infuscate basally, yellow infuscate distally; scutal chaetotaxy: notopleural, 4; supra alar, 1; post alar, 1; dorsocentral, 4–5; scutellar, 2. Abdomen dark brown medially with sparse grey pubescence, dark yellow to bright yellow laterally, male abdomen without silver velutum on tergites, male with elongate pale setae, denser laterally, dark posteriorly, female setae uniformly short and dark, erect; terminalia dark yellow. Male and female genitalia as per genus description except: epandrium dark brown, distiphallus narrow distally.

Comments. Pachyrrhiza subpictipennis sp. n. appears closely related to P. pictipennis , but is differentiated by the more mottled, lighter wing infuscation, and the abdomen with yellow laterally on most tergites. These characters in addition to the number of anteroventral macrosetae on the hind femur are distinctive for this species to separate it from others in the genus. Pachyrrhiza subpictipennis sp. n. is only known from a relatively small coastal region in northern Chile.

Type material. Holotype male, CHILE: Coquimbo Province: Fray Jorge National Park, 15 km SW. Pachingo [-30.5357, -71.6755], 100–200 m, 30.X.1966, M.E. Irwin ( MEI167377 ; MEUC) . Paratypes. CHILE: 4 males, 2 females, same data as holotype ( MEI167012 , 167035 , 167422 , 167424 , 167426–7 ; MEUC) ; 3 males, 1 female, Fray Jorge National Park, 15 km SW. Pachingo [-30.5357, -71.6755], 100–200 m, 20.X.1966, E.I. Schlinger, M.E. Irwin ( MEI167029 , 167418 , 167423 , 167447 ; CSCA) . Limari Province: 1 male, Fray Jorge National Park, Quebrada Honda I [-30.69, -71.63], Malaise in small wash, 7–24.XI.2003, M.E. Irwin, F.D. Parker, 122 m ( MEI166345 ; CSCA) ; 4 males, Fray Jorge National Park, Malaise in picnic area [-30.6396, -71.65], 250 m, 24.XI–12.XII.2003, F.D. Parker, M.E. Irwin ( MEI166327 , 166340 , 166346–7 ; CSCA) .

Figures

FIGURE 1. Pachyrrhiza subpictipennis sp. n., adult female (Photo copyright: Stephen A. Marshall).

FIGURE 26. Pachyrrhiza subpictipennis sp. n., adult male, oblique view.

FIGURE 27. Pachyrrhiza subpictipennis sp. n., adult male, lateral view.

FIGURE 28. Pachyrrhiza subpictipennis sp. n., adult female, oblique view.

FIGURE 29. Pachyrrhiza subpictipennis sp. n., 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 34. Pachyrrhiza spp. male genitalia, gonocoxites with aedeagus in situ, ventral view (left) and epandrium (right). A. P. parargentata sp. n.; B. P. pictipennis Philippi, 1865; C. P. subpictipennis sp. n. Scale line: 0.2 mm.

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