Pachyrrhiza elegantissima, 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 : 284-287

Pachyrrhiza elegantissima sp. n.

( Figs 13–17 , 30F, K , 31D , 33C , 35 )

Zoobank: urn:lsid:zoobank.org:act:74FB3CBC-DEB0-497B-A3AC-63169E392E8E

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 with fenestrations; male abdomen with silver velutum pubescence; mid coxal pile on posterior surface; femora brown.

Description. Body length: 6.0– 7.8 mm. Head with frons light brown pubescent dorsally, silver around antennal base, dark brown band above antenna (female), patch of short setae above antenna, female with sparse short setae; occiput with greyish-brown pubescence; parafacial with small dark patch adjacent to gena; genal setae pale; antennal scape length approximately twice maximum width, brown, overlain with grey pubescence, numerous erect, large black setae (larger in male); flagellum brown with grey pubescence. Thorax with scutum and scutellum grey pubescent with, narrow dark medial stripe, lateral stripes broken to sub-tessellate, numerous erect black setae (longer and denser anteriorly in male); prosternum with setae medially; pleuron with dense silver-grey pubescence, male with dark setae admixed with pale setae, katatergite with admixed pale and dark setae in both sexes; mid coxa with pale setae on posterior surface; femora dark brown, relatively elongate dark setae (especially in male) admixed with shorter setae; hind femur macrosetae with 3-6 anteroventral macrosetae spaced along entire length; tibiae yellow, dark grey-brown apically and sometimes basally; tarsi dark yellow with apices brown; wing dark mottled infuscate, fenestrate in some cells, costal cell brown infuscate basally, yellow infuscate distally; scutal chaetotaxy: notopleural, 4; supra alar, 1; post alar, 1; dorsocentral, 3–4; scutellar, 2. Abdomen base colour mostly dark brown with light brown to yellow along posterior margin and laterally, male abdomen with silver velutum on tergites 2–7, admixed with extensive long, pale setae, female setae black, short and erect; terminalia brown. Male and female genitalia as per genus description except: epandrium uniformly dark and distiphallus narrow distally.

Etymology. The specific epithet is derived from the Latin elegans, fine, tasteful, and - issimus, very; referring to the elegant appearance of this species.

Comments. Pachyrrhiza elegantissima sp. n. is known only from a coastal area in Ñuble Province. It is closely related to P. pictipennis and P. subpictipennis sp. n., but is differentiated by the silver velutum on the male abdomen and more extensive setal pile compared with the other two species.

Type material. Holotype female, CHILE: Ñuble Province : 5.6 km N. Cobquecura [approximated as -36.0884, -72.8062], 27.I.1967, on leaves of Lithrea , 10 m, E.I. Schlinger ( MEI167105 ; MEUC) . Paratypes. CHILE: Ñuble Province: 1 male, 6 females, same data as holotype ( MEI167356 , 167108 , 167111 , 167115 , 167120 , 167127 , 167130 ; MEUC, CSCA) ; 1 female, Cobquecura, Costa de Nuble [-36.1331, -72.7992], 14.XII.1953, L.E. Peña ( MEI167330 ; CNC) .

Figures

FIGURE 13. Pachyrrhiza elegantissima sp. n., adult male, oblique view.

FIGURE 14. Pachyrrhiza elegantissima sp. n., adult male, lateral view.

FIGURE 15. Pachyrrhiza elegantissima sp. n., adult male, dorsolateral view.

FIGURE 16. Pachyrrhiza elegantissima sp. n., adult female, oblique view.

FIGURE 17. Pachyrrhiza elegantissima 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 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.