Birketsmithiola nakuru, Volynkin, 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

Birketsmithiola nakuru sp. n.

( Figs 15, 16 , 26 , 32 )

Type material. Holotype ( Figs 15 , 26 ): male, [ Kenya] “26.vii.[19]52 | A. Townsend | Nakuru. Bred.| Eilema | sanguicosta.” / “Pres. by | Corydon Mus. | B.M. 1961-696” / QR-code label with unique number “ NHMUK 014173045 ”, gen. prep. No.: NHMUK010317202 (prepared by Volynkin) ( NHMUK).

Paratype: KENYA: 1 female, A. Townsend, Nakuru, 22.iii.[19]47 / Pres. by Corydon Mus. B.M. 1961-696 / unique number: NHMUK014173046 , gen. prep. No.: NHMUK010317203 (prepared by Volynkin) ( NHMUK).

Diagnosis. The forewing length is 16.5 mm in the male holotype and 16.0 mm in the female paratype. The new species is superficially reminiscent of B. smithi sp. n. but distinguished by the more elongate forewing with a more oblique tornus and a thinner red costal strip, and the presence of the brownish grey suffusion on the anterior area of the hindwing. Compared to another vaguely similar species, B. nyassana , B. nakuru sp. n. has a red head (it is orange in the aforementioned congener), a broader yellow costal streak, which is distally dilated, and bearing a broader red strip. The outer forewing margin of the new species is yellow whereas it is grey with only yellow cilia in B. nyassana . The male genital capsule of B. nakuru sp. n. has the thickest uncus and the distally broadest valvae in the species group. Additionally, the apical dentate crest of the juxta of the new species is markedly broader than in B. nyassana and B. bvumba sp. n. The phallus of B. nakuru sp. n. is medially broader and less upcurved than in other members of the species group. Additionally, compared to B. nyassana and B. bvumba sp. n., the midventral process of the phallus of the new species is longer and broader. The vesica structure of B. nakuru sp. n. is reminiscent of B. nyassana and B. bvumba sp. n. but the subapical diverticulum is semiglobular whereas it is conical in the aforementioned congeners. The female genitalia of the new species are most similar to B. nyassana but differ in the markedly narrower anterior sclerotised section of the ductus bursae, the more heavily sclerotised posterior section of the corpus bursae, and the somewhat shorter and narrower appendix bursae. Additionally, the lateral pockets of the 7 th female sternite of B. nakuru sp. n. are more heavily sclerotised than in B. nyassana .

Distribution. The new species is known from south-western Kenya ( Fig. 35 ).

Etymology. The specific epithet is homonymic of Nakuru County, Kenya, from where the new species is known. The name is a noun in the nominative singular in apposition.

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.