Metarctia (Hebena) rubra ( Walker, 1856 )

Fiebig, Ralf, László, Gyula M., Volynkin, Anton V. & Taberer, Tabitha R., 2023, Integrative taxonomic revision of the Metarctia Walker, 1855 subgenus Hebena Walker, 1856, with descriptions of six new species and one new subspecies (Lepidoptera: Erebidae: Arctiinae: Syntomini), Zootaxa 5339 (4), pp. 301-354 : 315-317

Metarctia (Hebena) rubra ( Walker, 1856)

(Figs adults 2a–l, 14, 24, 35–38; genitalia 41a–c, 53a–b; habitats 65–66)

Anace rubra Walker, 1856 , List of the specimens of lepidopterous insects in the collection of the British Museum, Part VII. Lepidoptera Heterocera, 7: 1720. Lectotype male (designated by Przybyłowicz (2009)). Type locality [ South Africa] Cape of Good Hope (coll. NHMUK).

Hexaneura cinnamomea Wallengren, 1860 syn. n., Wiener entomologische Monatschrift 4(6): 164. Holotype male, type locality [ South Africa] Caffraria (coll. SNHM).

Metarctia lateritia ab. lateritiola Strand, 1917 (infrasubspecific name), Archiv für Naturgeschichte 82 (A) (1916)(2): 82. Holotype male (not stated in the description), type locality [ South Africa] Natal (stated as “ Äthiopisch ” in the description) (coll. NHMUK).

Type material examined. Lectotype of Anace rubra Walker, 1856 , male, green ring label “Type” / [with handwritten] “ Cape G. Hope 42-77” / [with handwritten] “1683” / “3. ANACE RUBRA ” / [red printed label] “ LECTOTYPE ♂ Anace rubra Walker, 1856 des. Ł. Przybyłowicz 2005”, Arctiidae genitalia slide No. 5581, QR code label with unique id.: BMNH(E) 1378129 ( NHMUK).

Colour photo of the holotype of Hexaneura cinnamomea Wallengren, 1860 , published on the website of SMNH (http://www2.nrm.se/en/lep_nrm/c/hexaneura_cinnamomea.html) male, [printed] “Type” / [printed] “Caffraria.” / [with handwritten] “ Hexaneura cinnamomea Wallengr ” / [with handwritten] “I. Vohlb.” ( SNHM).

Holotype of Metarctia lateritia ab. lateritiola Strand, 1917, male (abdomen missing), red ring label “Type” / [with handwritten] “Natal 97. 187.” / [with handwritten] “1954/321” / [partly handwritten] Metarctia lateritia ab. lateritiola Strand Holotype ”, QR code label with unique id.: NHMUK 010915010 ( NHMUK).

Additional material examined. RSA. 1 male (externally matching with ab. lateritiola), “ Natal ” / “Rothschild Bequest B.M. 1939-1”, QR code label with unique id.: NHMUK 010917766 , gen. slide No. : NHMUK 010315178 ( LG 4703 ) ( NHMUK) ; 3 males, 1 female, Prov. Limpopo, Waterberg Mountain, Valwater 29 km NW, Moonriver Bush Bungalow, S 24°13’ E 28°23 ’, 27.–29.xi.2014 LF (Lichtfang), 1520m, leg. R. & S. Fiebig, DNA barcode id.: BC ZSM Lep 111872, BOLD process id.: GWOUH478-21, gen. slide No.: GP 36.748 ( RCRF); large series of both sexes with the same data, reared, DNA barcode id.: BC ZSM Lep 104712, BOLD process id.: GWOUC251-19 (female), DNA barcode id.: BC ZSM Lep 104711, BOLD process id.: GWOUC250-19, gen. slide No. : GP 36.670, gen. slide No.: RF 119.2016; RF 117.2016, DS 69-2015, HL2-2015, HL3-2016, HL4-2016 ( RCRF, RCHL, RCDS, RCTD, RCSS, RCWB) ; 1 male, Prov. Free State, eastern Drakensberg, ca. 30 km S Harrismith, Hlalanathi Reserve , 1280m, 14.–16.xii.2014, leg. De Freina, DNA barcode id.: BC ZSM Lep 104705, BOLD process id.: GWOUC244- 19, gen. slide No.: GP 36.555 ( RCRF) ; 2 males, 1 female, Prov. Free State, vic. Clarens, Sunnyside lodge, S 28°32’10” E 028°31’09”, 1810m, 27.–31.ii.2014, leg. M. Ströhle ; 61 males, 50 females, same data, reared, DNA barcode id.: BC ZSM Lep 111915, BOLD process id.: GWOUH519-21, DNA barcode id.: BC ZSM Lep 111913, BOLD process id.: GWOUH517-21, gen. slide Nos: RF 561.2020 (female), RF 560.2020 ( RCMS) ; 2 males, 3 females, same data, reared ; 1 male, Drakensberg , Hlalanathi, S 28°40’, E 29°02’; 1300m, leg. Klier ( RCSS) ; 1 male, KwaZulu-Natal, northern. Drakensberg-Region, Royal National Park—Region, Hlalanathi-Berg Resort , 1800m, 20–24.i.2002, leg. De Freina, gen. slide No.: GP 28.867 ; 1 male, Prov. Mpumalanga, 5 km SW Lydenburg, 1550m, 17.–21.xii.2009, leg. De Freina, gen. slide No.: GP 28.868 ; 1 female, Prov. Mpumalanga, 3 km NNE Lydenburg, 1600m, 15.–16.xii.2008, leg. De Freina, gen. slide No.: GP 32.197 ( MWW) ; 1 male, KwaZulu-Natal, Nottingham road, Farm 7 km S of Fort Nottingham, 1450m, at light, 29°29’17.0”S 29°53’48.7”E, 07.ii.2015, leg. D.Bartsch, gen. slide No.: RF 618.2021 ; 1 female, KwaZulu-Natal, Drakensberg, Lotheni NR, 1556m, at light, 21.i.2018, 29°26’15.0”S 29°30’53.9”E, leg. D. Bartsch, gen. slide No.: RF 617.2021 ( SNMS) ; 1 male, Kwazulu-Natal, Oliviershoekpass Nr. Swiss Farm, 01.i.2006, BC ISEZ-DNA 604, leg. H.E.T. Selb ; 2 males, Ukhahlamba-Drakensberg Park, Cathedral Peak, Main Gate , 28.56°S 29.14°E, 1360m, at light, 01.xii.2004, leg. L. Przybyłowicz, gen. slide No.: ISEA PAS 5.12 .7 ( ISEA PAS).

Taxonomic note. Examination of the male genitalia of monochromatic cinnamon-coloured specimens from South Africa revealed their conspecificity with M. rubra , revealing the species has two forms: one with fuscous grey forewing ornamented by red highlighted venation (“ rubra ” form) reminiscent also of M. lateritia , and another with uniform cinnamon forewing without contrasting red venation (“ cinnamomea ” form). Thus, the junior name H. cinnamomea is sank into synonymy with M. rubra Walker, 1856 : Metarctia cinnamomea ( Wallengren, 1860) syn. n.. Strand (1917) also described the monochromatic form of M. rubra as an aberration of M. lateritia (ab. lateritiola) introducing thus an infrasubspecific, consequently unavailable name.

Diagnosis. The widespread form of M. rubra with red highlighted venation is highly reminiscent of M. lateritia and the species of the M. smithi lineage. Due to this, only the freshly hatched, intact specimens could be told apart based on the more intense orange-red hue of the colour of the veins and the terminal line of the forewing, and the paler, more yellowish fringe often with greyish apical section of M. rubra . The forewing underside has considerably more extensive salmon colouration covering at least the basal two-thirds of the wing surface in M. rubra compared to M. lateritia and M. smithi . The tibia of the mid- and hind legs of M. rubra possesses small red-orange hairs dorsally, whilst the tibia of M. lateritia is strongly covered in reddish hairs dorsally. In the M. smithi — M. haraldsulaki species-pair, the tibia is generally uniformly black or dorsally with very small, red-orange hairs. However, DNA barcoding or dissection is required for unequivocal identification. The monochromatic pale form of M. rubra is confusingly similar to M. manfredi but their allopatric distribution excludes the possibility of misidentification. In the male genitalia, M. rubra has the shortest basal projection of the valva costa in the subgenus without extensive setation, being somewhat similar to that of M. brigitta , but the latter species has a pointed, apically setose costal projection.Additionally, the distally tapering terminal process of the valva is more robust than in most other species of the subgenus, except for M. venustissima which has broadly rounded valva apex. Metarctia smithi , M. haraldsulaki and M. manfredi are characterized by the bifid tip of the valva. The female genitalia configuration of M. rubra is very similar to that of M. brigitta , distinguished only by the narrower ostium bursae with less sclerotized antero-lateral margin.

Description. Adult. Forewing length 24–32 mm in males, 26–33 mm in females. Male antenna bipectinate-ciliate, black, rami ca. 4 times longer than diameter of shaft, cilia very short, white. Female antenna serrate, rather thick, black. Head. Small, proboscis small, labial palp short, dark grey. Compound eye small, spherical, frons and vertex crimson. Thorax. Collar crimson, tegula crimson with orange-red margin; mesothorax crimson. Legs. Coxa and femur covered in thick crimson to orange-red hairs, tibia of all legs pale orange-red ventrally, black dorsally; tarsus black; index of spurs: 0-2-2. Forewing. Moderately broad, elongate, especially in female, dorsal margin almost straight, subapically slightly convex, apex rounded, outer margin long, evenly arcuate, anal margin short, almost straight. Ground colour fuscous-grey in general form with red-highlighted venation, cinnamon to salmon in monochromatic form; veins covered in salmon to crimson scales; transverse lines absent, except for contrasting terminal line; fringe short, monochromatic ochreous to pale-orange, sometimes with greyish suffusion at apex. Underside. Basal two-thirds of surface monochromatic orange-red to salmon, with slightly darker veins; apical third dark graphite-grey between veins. Hindwing. Well-developed, short and narrow, apically rounded, uniformly orange-red to salmon without marking; fringe short, colour as of hindwing. Underside as upperside. Abdomen. Stout, orange-red, ringed with black proximally.

Male genitalia. Uncus short and stout, dorsally dilated, evenly arched, subapically slightly curved, apically pointed. Tegumen short and narrow, arms fused in distal half. Valva very broad at base, transtilla short, costal margin with a short, rounded basal projection with sparse setae; distal margin concave, terminal process of valva robust, rather long, distally slightly flexed, apically pointed. Sacculus short and narrow, with sparsely setose distal crest and short, rounded basal projection. Anellus (fultura superior) and juxta (fultura inferior) fused, distal half quadrangular with very broad margins, proximal half basally bifurcate, medially tapered. Vinculum moderately long, V-shaped. Phallus short and thin with coecum elongate and rounded, medially gently curved, apex without carina process. Vesica with slightly dilated proximal section bearing a small, finely spinulose subbasal field dorsally, distal section of vesica narrow, tubular.

Female genitalia. Papilla analis short, rounded-quadrangular, finely setose; posterior apophysis short (ca. as long as papilla analis), thin, pointed. Eighth tergite short, ribbon-like; anterior apophysis very short. Ostium bursae narrow with U or V-shaped sclerotized margin, lamella postvaginalis present, broad ribbon-like, longitudinally striate, interconnected with large, rounded triangular lamellae antevaginales. Ductus bursae narrow, short, tubular, distal half sclerotized, proximal half membranous, cervix bursae unmodified. Tubular distal part of corpus bursae membranous, ca. third as long as ductus bursae; dilated proximal section of corpus bursae large, ovoid; signum bursae represented by a very long, ovoid, finely scobinate field.

Genetic information. The species has been assigned the BIN URI: BOLD:ADR5524. The infraspecific divergence is 0.00−0.46%. The nearest neighbour of M. rubra is M. brigitta , with a pairwise distance of 2.35%. The pairwise distance between M. rubra and M. elleni is 2.68−3.40%. The species diverges from topotypical population of M. lateritia (BIN URI: BOLD:AAZ9706) at 5.31−6.45%, while the distance to the nominate taxon of M. smithi is in the range of 5.24−6.80%.

Distribution ( Map 2 ). This species is only known from South Africa.

Figures

MAP 2. Distribution of Metarctia (Hebena) rubra, M. (H.) manfredi, M. (H.) kelleni, M. (H.) elleni and M. (H.) brigitta.