Metarctia (Hebena) smithi transvallesiana 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 : 324-325

Metarctia (Hebena) smithi transvallesiana Fiebig, László, Volynkin & Taberer ssp. n.

(Figs adults 8a–c, 20, 30; genitalia 47, 57)

Holotype. male “ Tanzania, Katavi Region, Mpanda Doto, near Majalila Village , 1237m., 06°07.636’S, 030°56.524’E, 06-xii-2012 (Ph. Darge) DNA barcode id.: BC ZSM Lep 111887, BOLD process id.: GWOUH491-21, gen. slide No.: GP 36.754 ( RCRF, later ZSM).

Paratypes (44 males, 4 females in total). Tanzania . 4 males, 1 female, same data as in the holotype, DNA barcode id.: BC ZSM Lep 113372, BOLD process id.: GWOUH931-21, gen. slide No.: RF 613.2021 (female), DNA barcode id.: BC ZSM Lep 111923 BOLD process id.: GWOUH527-21, gen. slide No.: RF 606.2021, gen. slide No.: RF 614.2021, 9 males, 1 female, same site, 1.xii.2012, DNA barcode id.: BC ZSM Lep 104707, BOLD process id.: GWOUC246-19, gen. slide No.: GP 30.960 (female), DNA barcode id.: BC ZSM Lep 111925, BOLD process id.: GWOUH529-21, gen. slide No.: RF 605.202 ( RCRF, ZSM); 1 female, Morogoro Region , Uluguru Mts. , Bunduki Forest Res. , 1275m, 07°01.679’S 037°37.945’E, 12.xii.2008, leg. Ph. Darge ( RCMO); 1 female, Iringa Region , Kipengere Mts. , Lugenge Morland , 2060m, 09°24.864’S, 034°34.822’E, 10.i.2006, (local collector) leg. Ph. Darge, GP 32.192 ( MWW); 1 male, Njombe District, Ulembwe, 09°18.704’S, 034°38.083’E, 2079m, 26.xii.2010, leg. Ph. Darge, gen. slide No.: GP 28.703 ( MWW / ZSM), 28 males, same site, 5.xii.2013, gen. slide No.: RF 2022.326; RF 2022.325 leg. Ph. Darge; 1 male, Tanga Region , Tamota Forest, 05°35.531’S 037°33.129’E, 731m, 27.xi.2015, leg Ph. Darge, gen. slide No.: RF 2022.324; 1 male, Iringa , Makete District, Kungu Village, 2370m, 1.–28.ii.2014, leg. W. Kilumile, gen. slide No.: RF 2022.315 ( RCRF, ZSM) .

Diagnosis. The new subspecies of M. smithi is distinguished from the nominate taxon in the following genitalia characters: M. smithi transvallesiana ssp. n. has a rounded tegumen without a lateral protrusion which is present both in M. smithi as well as M. haraldsulaki . In addition, the terminal process of the valva is noticeably shorter in the Tanzanian taxon compared to its congeners. In the female genitalia, M. smithi transvallesiana has a narrower lamella postvaginalis and considerably longer and narrower signum bursae than those of the nominate subspecies.

Description. Adult. Forewing length 19–22 mm in males, 23–25 mm in females. The external features of M. smithi transvallesiana are identical to those of the nominate subspecies.

Male genitalia. Uncus short, basally with a swollen dorsal bulge, medially gently curved, apically pointed with apex directing ventrad. Uncus base dilated with rounded, dentate margin. Tegumen short and narrow, arms arcuate, ventral margin finely dentate, without lateral lobes, arms fused below uncus base. Valva very broad at base, transtilla short, costal margin without projection and setae; valva costa directly continued in very short, distally dilated, apically bifid terminal process of valva bearing a short, rounded ventral process and a longer, pointed dorsal process. Sacculus short and very narrow, distally with a setose gently arcuate crest. Anellus (fultura superior) large, more or less quadrangular, fused with inverse Y-shaped juxta (fultura inferior). Vinculum moderately long, distal section produced, apex rounded. Phallus moderately long and thin bearing a longitudinal belt of small spinules, medially slightly arched, coecum very short, rounded, apex without carina process. Vesica with slightly dilated proximal section bearing a small, densely spinulose subbasal field dorsally, and an extensive spinulose area ventrally consisting of extremely small spinules; distal section of vesica narrow, tubular.

Female genitalia. Papilla analis short, rounded-trapezoidal, barely setose; posterior apophysis moderately long (ca. as long as papilla analis), thin, pointed. Eighth tergite very short, evenly arched, ribbon-like; anterior apophysis almost fully reduced. Eighth sternite with a very broad V-shaped, heavily sclerotized, distally and a pair of finely scobinate, very small, sack-like projections proximally. Ostium bursae narrow with moderately sclerotized margin. Lamella postvaginalis present, narrow ribbon-like, heavily sclerotized, fully fused with amorphous, rugose lamella antevaginalis. Ductus bursae strongly sclerotized, short, relatively thick, tubular; cervix bursae unmodified. Tubular distal part of corpus bursae membranous, very short, one-third as long as ductus bursae; dilated proximal section of corpus bursae large, spherical; signum bursae represented by a long (ca. half as long as bursa copulatrix) and narrow, strongly sclerotized, scobinate field.

Genetic information. This taxon is assigned the BIN URI: BOLD:AED5120. Metarctia smithi transvallesiana is the only cluster within the diverse M. smithi lineage with clear diagnostic morphology and isolated distribution. The infraspecific divergence is 0.00−0.68%, and the nearest neighbour of the subspecies is the nominate M. smithi with a pairwise distance in the range of 3.14−4.50%. It is worth mentioning that the M. smithi transvallesiana cluster recovered as a sister to one of the M. smithi sub-clusters (AEM2044/AEM2045), although at a relatively low (78%) PP, rather than being a sister lineage of the entire M. smithi smithi clade which could be expected based on their distinct morphology and distribution. This is an additional example of the occasional incongruence between the morphological hypotheses and the genetic analysis based merely on DNA barcodes.

Etymology. The subspecific epithet of the new taxon refers to its distribution isolated from the nominate subspecies by the Rift Valley: the latin prefix “trans” meaning “beyond” and the latin noun “valles” meaning “valley”.

Distribution ( Map 3 ). The species is known only from Tanzania, with confirmed records from the highlands along the Eastern and Western Rift Valley.

Figures

MAP 3. Distribution of Metarctia (Hebena) smithi smithi, M. (H.) smithi transvallesiana and M. (H.) haraldsulaki