Metarctia (Hebena) elleni Fiebig, László, Volynkin & Taberer, 2023

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 : 319-320

Metarctia (Hebena) elleni Fiebig, László, Volynkin & Taberer sp. n.

(Figs adults 5a–c, 17, 27; genitalia 44)

Holotype. male, “ TANZANIE: Rukwa Region, Mbizi Mts Forest Reserve , 07°53.014’S, 031°41.990’E., 2200m., moor land, 10-xii-2015 (Ph. Darge)”, DNA barcode id.: BC ZSM Lep 104704, BOLD process id.: GWOUC243-19, gen. slide No.: GP 30.955 ( RCRF, later ZSM).

Paratype. Tanzania. 1 male, same date as in the holotype, DNA barcode id.: BC ZSM Lep 104716, BOLD process id.: GWOUC255-19 ( RCRF) .

Diagnosis. Metarctia elleni sp. n. is distinguished from all Hebena species by the dark graphite-grey forewing ground colour, being one of the darkest taxon in the subgenus ( M. venustissima is similarly dark but rather brownish-black). Also, it possesses very narrow but highly contrasting red venation (the reddish highlight of the veins is wider in other Hebena species), a thin, but conspicuous salmon terminal line followed by the dark grey fringe of the forewing, a narrow grey dorsal area bordered with salmon margin (dorso-apical section of the terminal line), and a grey apical section of the fringe of the hindwing. The dark brown colouration of the thorax is also unique in the subgenus. In the male genitalia, the new species is readily distinguished from all other Hebena taxa by the very long and narrow, finger-like, weakly setose basal process of the valva costa and the deeply notched, extremely long distal margin of the valva stretching between the costal and the terminal processes, somewhat similarly to that of M. lateritia .

Description. Adult. Forewing length 30–36 mm in males. Male antenna bipectinate-ciliate, black, rami ca. 5 times longer than diameter of shaft, cilia very short, white. Head. Small, proboscis small, labial palp short, crimson, tip and dorsal side black. Compound eye small, spherical, frons and vertex brownish-red. Thorax. Collar brownish-red, tegula dark brown with admixture of reddish hair-scales basally; mesothorax dark brown with red-brown medial line. Legs. Coxa and femur covered in thick crimson hairs, foreleg tibia with orange-red hairs dorsally, middle leg with very sparse orange-red hairs dorsally, hindleg tibia black, ventral side of tibia black in all leg, tarsus entirely black; index of spurs: 0-2-2. Forewing. Moderately broad, elongate, dorsal margin almost straight, subapically slightly convex, apex rounded, outer margin long, evenly arcuate, anal margin short, almost straight. Ground colour dark graphite-grey; veins covered in crimson scales; transverse lines absent, terminal line present, very narrow, pinkish orange; fringe short, monochromatic dark graphite grey. Underside. Similar to upperside with more extensive reddish suffusion in basal quarter and along costa, veins highlight broader, less contrasting pinkish-orange. Hindwing. Well-developed, short and narrow, apically rounded, monochromatic salmon with very narrow graphite-grey dorsal area; marking absent except for short salmon dorso-apical section of terminal line; fringe short, pale ochreous, graphite-grey apically. Underside as upperside. Abdomen. Stout, crimson, ringed with black proximally.

Male genitalia. Uncus stout, moderately long, 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 long and narrow, apically rounded, digitiform basal projection covered in fine, short setae; distal margin almost straight, very slightly concave, terminal process of valva short, basally broad, distally tapered, apically pointed. Sacculus short and narrow, bearing a setose distal crest. Anellus (fultura superior) inverse-trapezoidal with very narrow distal and narrow lateral margins, fused with basally bifurcate, distally narrow, ribbon-like juxta (fultura inferior). Vinculum moderately long, medially produced into digitiform process with rounded apex. Phallus relatively long, thin, somewhat dilated proximally with elongate, rounded coecum, medially evenly arcuate, 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 unknown.

Genetic information. The species has been assigned the BIN URI: BOLD:AED5536. The infraspecific divergence is 0.66%. The nearest neighbour of M. elleni is M. rubra , diverging at a pairwise distance of 2.68−3.40%. The species diverges from topotypical population of M. lateritia (BIN URI: BOLD:AAZ9706) at 5.72−6.53% (compared with the full range of genetic clusters of M. lateritia the distance is in the wide range of 4.72−8.80%), while the distance to the nominate taxon of M. smithi sp. n. is in the range of 5.21−7.61%.

Etymology. The species is dedicated to Ellen Wetzel (Schönfeld, Germany), in gratitude for supporting the entomological research activities of the first author.

Distribution. Metarctia elleni is known only from its type locality in Tanzania, within a small isolated patch of mountainous forest in the south part of the Western Rift Valley.