Rinhatiana latifestuca, Irwin & Winterton, 2024

Irwin, Michael E. & Winterton, Shaun L., 2024, New genera of stiletto flies endemic to Madagascar (Therevidae: Therevinae), European Journal of Taxonomy 932 (1), pp. 1-33 : 14-17

Rinhatiana latifestuca gen. et sp. nov.

urn:lsid:zoobank.org:act:43F805DB-3FBE-4E56-B935-A4995BD93673

Figs 7–8 , 9G–H , 15C , 16E–F, O , 18

Diagnosis

Frons entirely matte black and silver pubescent, without tan pubescence dorsally ( Fig. 9G–H ); male eyes nearly contiguous; single row of postocular macrosetae in both sexes; dorsocentral macrosetae absent; one pair of supra alar macrosetae ( Figs 7–8 ); abdomen yellow with silver pubescence laterally.

Differential diagnosis

Rinhatiana latifestuca gen. et sp. nov. differs from all other members of the genus by a distinctive pattern of frontal pubescence ( Fig. 9G–H ) and predominantly yellow abdomen. Amongst other characters, it differs from R. cracentis gen. et sp. nov. by the bright silver pubescence around the base of the antennae (silver-tan in R. cracentis ), from R. distincta by the presence of a single pair of supra alar macrosetae (two pairs in R. distincta ), and from R. arctifestuca gen. et sp. nov. by the absence of tan pubescence dorsally on the frons (present in R. arctifestuca ). In addition, the matte black pubescence on the dorsal portion of the female frons is wider in this species than in that of R. arctifestuca .

Etymology

The specific epithet is derived from the Latin ʻ latus ʼ (ʻbroadʼ) and ʻ festuca ʼ (ʻstalkʼ). Gender is female.

Material examined

Holotype MADAGASCAR – Tulear Province (Atsimo-Andrefana Region) • ♂; Ambohimahavelona ; 23.4408° S, 43.8996° E; 45 m a.s.l.; 27 Dec. 2008 – 2 Jan. 2009; M.E. Irwin and R. Harin’Hala leg.; Malaise in spiny forest dry wash; CASC.

Paratypes MADAGASCAR – Tulear Province (Atsimo-Andrefana Region) • 4 ♂♂, 3 ♀♀; same collection data as for holotype; various dates: 27 Dec. 2008 – 2 Jan. 2009, 17–24 Nov. 2015, 27 Dec. 2015 – 6 Jan. 2016; Malaise traps in hillside wash and deciduous dry forest; CASC • 13 ♂♂, 10 ♀♀; 4 km N of Manombo ; 22.9036° S, 43.4755° E; 30 m a.s.l.; various dates: 12–27 Nov. 2001, 3–13 Oct. 2002, 8–19 Feb. 2002, 6–17 Mar. 2003, 2–12 Oct. 2003, 14–28 Nov. 2002; M.E. Irwin and R. Harin’Hala leg.; Malaise in Mikea deciduous dry forest; CSCA • 2 ♂♂, 2 ♀♀; 4 km NNW of Manombo; -22.9133, 43.4821; 37 m a.s.l.; 6–17 Jan. 2002; M.E. Irwin and R. Harin’Hala leg.; Malaise in spiny forest; CASC • 1 ♂; 5 km SE of Manombo ; 22.9863° S, 43.5022° E; 17 m a.s.l.; 20–30 Oct. 2008; M.E. Irwin and R. Harin’Hala leg.; Malaise on path in dense forest ; • 1 ♀; 3 km E of Itampolo; 24.6578° S, 43.9562° E; 45 m a.s.l.; 18– 27 Mar. 2010; M.E. Irwin and R. Harin’Hala leg.; Malaise across path in Androimpano dry forest; CASC • 1♂, 1♀; 27 km N of Tongobory ; 23.3461° S, 44.3581° E; 289 m a.s.l.; 22–30 Oct. 2008; M.E. Irwin and R. Harin’Hala leg.; Malaise in damp wash with spiny scrubland; CASC. – Tulear Province (Androy Region) • 2 ♂♂, 1 ♀; 5 km N of Ampotaka ; 25.0303° S, 44.6915° E; 86 m a.s.l.; 27 Oct.–5 Nov. 2008; Malaise on trail on Vitambany gallery forest; CASC .

Other material

MADAGASCAR – Tulear Province (Atsimo-Andrefana Region) • 27 ♂♂, 19 ♀♀; Ambohimahavelona ; 23.4408° S, 43.8996° E; 45 m a.s.l.; various dates: 27 Dec. 2008 – 2 Jan. 2009, 17–24 Nov. 2015, 27 Dec. 2015 – 6 Jan. 2016; M.E. Irwin and R. Harin’Hala leg.; Malaise traps in hillside wash and deciduous dry forest; CASC .

Description

BODY LENGTH. 5.5–7.0 mm (male), 6.5–8.0 mm (female).

HEAD. Frontal pubescence with matte black band medially, extending dorsally and ventrally (female), matte black dorsally (male), silver ventrally; male frons width at narrowest point with eyes nearly contiguous; frontal vestiture absent; ocellar tubercle gray pubescent, without setae; black postocular macrosetae in single row immediately laterad of ocellar tubercle in both sexes; occiput pubescence silver-gray, brown suffusion medially; genal setae pale; antennal scape shorter than flagellum, cylindrical, dark yellow-orange, overlain with gray pubescence, sparsely covered with short, dark macrosetae; flagellum conical, tapered distally, style elongate, orange-yellow, terminus dark.

THORAX. Scutum uniform gray-tan or with brown markings, sparse short pale setae; scutellum concolorous with scutum; pleuron with dense silver-gray pubescence, darker in male; katatergite setae pale; scutal and scutellar macrosetae black; coxae yellow, overlain with silver-gray pubescence, minor setae white, macrosetae black, few in number; femora yellow, short dark setae admixed with longer pale setae and white adpressed scale-like setae, especially on hind leg; hind femur with single subapical anteroventral macroseta, subapical series of short posteroventral macrosetae; tibiae yellow, dark gray-brown suffusion apically, darker on hind leg; tarsi brown; wing smoky infuscate; venation yellow basally along major veins, darker distally; scutal chaetotaxy (pairs): notopleural, 3; supra alar, 1; post alar, 1; dorsocentral, 1; scutellar, 2.

ABDOMEN. Male dark yellow, silver velutum present posterolaterally on tergites 1–5 in both sexes, pale elongate setae, darker on posterior segments and terminalia in male, female abdomen dark yellow, intersegmental membrane distinctly pale, especially on tergite 2; terminalia dark yellow in both sexes.

MALE GENITALIA. Epandrium quadrangular, strongly arched along midline; gonocoxites with elongate macrosetae laterally; outer gonocoxal process well developed and narrowly subtriangular; ventral lobe elongate, membranous apically; gonostylus narrow; distiphallus very narrow and recurved; sternite 8 sub-quadrangular, emarginate medially, setae along posterior margin.

Remarks

Rinhatiana latifestuca gen. et sp. nov. is very similar in appearance to R. arctifestuca gen. et sp. nov., especially in the frontal pubescence pattern. This species appears restricted to southern Madagascar where it has been collected in spiny thicket habitats ( Fig. 18 ; inset).

Figures

Fig. 7. Rinhatiana latifestuca gen. et sp. nov., ♂, paratype (CASC). A. Lateral view. B. Oblique view.

Fig. 8. Rinhatiana latifestuca gen. et sp. nov., ♀, paratype (CASC), lateral view.

Fig. 9. Rinhatiana spp., heads, anterior view. A. Rinhatiana arctifestuca gen. et sp. nov., ♂ (CSCA). B. Same, ♀ (CSCA). C. Rinhatiana cracentis gen. et sp. nov., ♂ (CSCA). D. Same, ♀ (CSCA). E. Rinhatiana distincta (Lyneborg, 1976) comb. nov., ♂ (CSCA). F. Same, ♀ (CSCA). G. Rinhatiana latifestuca gen. et sp. nov., ♂ (CSCA). H. Same, ♀ (CSCA).

Fig. 15. Rinhatiana gen. nov. and Tianarinha gen nov., epandrium. A. Rinhatiana arctifestuca gen. et sp. nov. (CSCA). B. Rinhatiana cracentis gen. et sp. nov. (CSCA). C. Rinhatiana latifestuca gen. et sp. nov. (CSCA). D. Rinhatiana distincta (Lyneborg, 1976) comb. nov. (CSCA). E. Tianarinha micet gen. et sp. nov., epandrium and tergite 8. (CSCA). F. Tianarinha goodmani gen. et sp. nov. (CSCA). Scale bar = 0.2 mm.

Fig. 16. Rinhatiana gen. nov. andTianarinha gen nov.A–K. Male gonocoxites and phallus with epandrium removed. A. R. arctifestuca gen. et sp. nov. (CSCA), ventral view. B. Same, dorsal view. C. R. cracentis gen. et sp. nov. (CSCA), ventral view. D. Same, dorsal view. E. R. latifestuca gen. et sp. nov. (CSCA), ventral view. F. Same, dorsal view. G. T. goodmani gen. et sp. nov. (CSCA), ventral view. H. Same, dorsal view. I. T. micet gen. et sp. nov. (CSCA), ventral view. J. Same, dorsal view. K. R. distincta (Lyneborg, 1976) comb. nov. (CSCA), ventral view. L–P. Sternite 8. L. R. arctifestuca gen. et sp. nov. (CSCA) (with tergite 8). M. R. cracentis gen. et sp. nov. N. T. goodmani gen. et sp. nov. (CSCA). O. R. latifestuca gen. et sp. nov. (CSCA). P. T. micet gen. et sp. nov. (CSCA). Scale bars = 0.2 mm.

Fig. 18. Distribution of species of Rinhatiana gen. nov. with eco-regions indicated. Inset image of adult ♀ of R. latifestuca gen. et sp. nov. (photograph copyright: Len de Beer).