Birketsmithiola nyassana ( Strand, 1912 ), 2022

Volynkin, Anton V., 2022, Taxonomic review of the Afrotropical genus Birketsmithiola Krüger with descriptions of five new species (Lepidoptera: Erebidae: Arctiinae), Zootaxa 5205 (1), pp. 73-86 : 79-85

Birketsmithiola nyassana ( Strand, 1912) , stat. rev.

( Figs 13, 14 , 27 , 33 )

Eilema sanguicosta var. nyassana Strand, 1912 , Archiv für Naturgeschichte, 78 A (7): 180 (Type locality: [S Tanzania, Rungwe District , Tukuyu ] “ Nyassa-See, Langenburg ”).

Type material examined. Lectotype (hereby designated) ( Figs 13 , 27 ): male, [ Tanzania], blue label “Nyasa-See | Langenburg | Kamso.B.d.Pyramidenbgs. | 23. 24.II.[18]99 | Fülleborn S.” / grey label “ Nyasa-See | Langenburg | Kamso.B. d.Pyramidenbgs. | 23. 24.II.[18]99 | Fülleborn S. ” / red label “Type” / “ ♂ ” / “ Ilema san- | guicosta | H. var. | nyassana | m. | Strand det. ♂ ”, gen. prep. No.: MfN 385 (prepared by Volynkin) ( MfN).

Paralectotypes: 3 females, blue label “Nyasa-See | Langenburg | Pyramide u.Umgegend | 23.II.–3.III.[18]99 | Fülleborn S.” / grey label “ Nyasa-See | Langenburg | Pyramide u. Umgegend | 23.II.–3.III.[18]99 | Fülleborn S. ” / red label “Type” / “ ♀ ” / “ Ilema san- | guicosta | H. v. nyas- |sana m. | Strand det. ♀ ”, gen. prep. No.: MfN 386 (prepared by Volynkin) ( MfN).

Notes. (1) Krüger (2015) considered this taxon as an unavailable name. However, in the original description, Strand (1912) wrote the following: “Da die Art etwas variirend ist und nur im einem Geschlecht (Weibchen) nach einem Unikum beschrieben, so dürfte es warscheinlich sein, dass die angegebenen Unterschiede nicht spezifisch sind. Ich führe daher die Form forlaufig als eine Varietät auf.” (“It is very probable that the indicated differences are not specific, as the species varies slightly and is described from a single sex (female) and only based on one specimen. Therefore I am listing the form provisionally as a variety.”), which is not a statement that the name is infrasubspecific but an explanation of why the author described nyassana as a variety and not a full species. According to ICZN Article 45.6.4 (1999), a name first published before 1961 as a ‘variety’ is subspecific and, thus, available. Since it is clearly morphologically different from B. sanguicosta , the taxon is hereby upgraded to species level. It is also worth mentioning that Strand’s statement that B. sanguicosta was described from a single female is erroneous as in the original description of the species, Hampson (1901) clearly listed two “Type” males, which are currently deposited in the NHMUK collection (see above). (2) The type series of the species contains four specimens. In order to stabilise the nomenclature, the male syntype is hereby designated as lectotype.

Diagnosis. The forewing length is 15.0 mm in the male lectotype and 16.0 mm in the females. Birketsmithiola nyassana is most morphologically similar to B. bvumba sp. n. and the detailed comparison of the habitus and the male genitalia of these species is provided below in the diagnosis of B. bvumba sp. n. Since the female of B. bvumba sp. n. is unknown, the female genitalia of B. nyassana are compared to B. nakuru sp. n. instead. In B. nyassana , the anterior sclerotised section of the ductus bursae is broader, the posterior section of the corpus bursae is more weakly sclerotised, and the appendix bursae is more elongate than the corresponding structures of B. nakuru sp. n. Females of other species in the genus, namely B. transvaalensis , B. kruegeri sp. n. and B. smithi sp. n. have a markedly broader and more heavily sclerotised posterior section of the corpus bursae than in B. nyassana .

Distribution. The species is currently known only from its type locality in southern Tanzania ( Fig. 35 ).

Figures

FIGURE 35. Distributional map of Birketsmithiola spp.

FIGURES 9–16. Birketsmithiola spp.: adults. Depositories of the specimens: 9–10 in ANHRT; 11 in AKW; 12 in ZSM; 13 and 14 in MfN; 15 an 16 in NHMUK (©The Trustees of NHMUK).

FIGURES 25–28. Birketsmithiola spp.: male genitalia. Depositories of the specimens dissected: 25 in ANHRT; 26 in NHMUK (©The Trustees of NHMUK); 27 in MfN; 28 in ZSM.

FIGURES 29–33. Birketsmithiola spp.: female genitalia. Depositories of the specimens dissected: 29, 30 and 32 in NHMUK (©The Trustees of NHMUK); 31 in ANHRT; 33 in MfN.