Gracililema bettoni, Volynkin, 2022

Volynkin, Anton V., 2022, Taxonomic review of the Afrotropical genus Gracililema Krüger with descriptions of three new species (Lepidoptera: Erebidae: Arctiinae: Lithosiini), Zootaxa 5115 (1), pp. 63-78 : 68

Gracililema bettoni sp. n.

( Figs 5–7 , 19, 20 , 27 )

Type material. Holotype ( Figs 5 , 19 ): male, [ Kenya] “ E Quaso. Masai. B.E.Africa. 23.x.1900. C.S.Betton. 1901- 136.” / QR-code label with unique number: “ NHMUK 014173087 ” / “Slide NHMUK 010317201 ” ( NHMUK).

Paratypes (5 males and 2 females): KENYA : 1 male, Gwelil. [= Goelil, 0˚30’S, 36˚05’E] B. E. Africa. C.S. Betton. 20.IX.1900. 1901–27,. gen. prep. No.: BMNH Arctiidae 587, unique number: NHMUK 010889645 ( NHMUK) ; 1 female, [ Eburru ] Eb Urru, B. E. Africa, 30. V .1900, C.S. Betton, 1900–221, gen. prep. No.: BMNH Arctiidae 588, unique number: NHMUK 010889646 ( NHMUK) ; 1 male, Eastern Province, Meru District, Lewa Conservancy , 2080m, N0˚08.235’, E37˚27.282’, 28–30.xi.2008, A.J. Kingston [leg.], gen. prep. No.: AV6534 ( AKW) ; 1 male, Africa or., Mt. Kenya, Nanyuki , 8.XII.[19]60, H. Löffler leg., gen. prep. No.: ZSM Arct. 2021-177 (prepared by Volynkin) ( ZSM) ; 1 male, Kabete , 29.X.1972, H. Politzar leg., gen. prep. No.: ZSM Arct. 2021-178 (prepared by Volynkin) ( ZSM) ; 1 female, Kakamega, 1.X.1973, H. Politzar leg., gen. prep. No.: ZSM Arct. 2021-179 (prepared by Volynkin) ( ZSM) ; ETHIOPIA: 1 male, 07°17’00’’N, 36°07’58’’E, 11.2 km W Bonga, 01.xi. 2010, 2050m, Li [at light], J. De Freina, H. Hacker, H. Peks, H.-P. Schreier leg., gen. prep. No.: ZSM Arct. 2020-221 (prepared by Volynkin) ( ZSM) .

Remark. The type locality of “E Quaso. Masai.” almost certainly refers to the Guaso Masai stream (0˚13’S, 35˚47’E) in the area between modern day Molo and Elburgon just to the north of the Mombasa-Victoria railway line (H. Takano 2021, pers. comm.).

Diagnosis. The forewing length is 15.0–15.5 mm in males and 16.0 mm in the female paratype. Gracililema bettoni sp. n. ( Figs 5–7 ) is distinguished from its congeners ( Figs 1–4, 8–16 ) by its larger size. The wide yellow costal stripe is similar to that of G. lydiae sp. n. ( Figs 8–11 ) but in the male of` G. bettoni sp. n., it is dilated subapically. Additionally, the forewing of G. bettoni sp. n. has a somewhat more acutely angled apex in the male, and a more rounded tornus in the female. The male genitalia of G. bettoni sp. n. ( Figs 19, 20 ) are most similar to those of G. proleuca ( Figs 17, 18 ) but differ in the slightly thinner distal saccular process, the markedly broader vesica and the longer and thicker cornutus. Additionally, the uncus of G. bettoni sp. n. is somewhat more elongate than in G. proleuca (ca. 1.15 times longer than the tegumen while the uncus and the tegumen of G. proleuca are equal in length). Compared to that of G. lydiae sp. n. ( Figs 21, 22 ), the male genital capsule of the new species has a shorter uncus and distal saccular process. The vesica of the new species is markedly longer (equal to the length of the phallus tube in G. bettoni sp. n. as opposed to half the length in G. lydiae sp. n.) and broader than in G. lydiae sp. n., curved dorsally (it is curved laterally in the congener), and the cornutus is longer and thicker. The female genitalia of G. bettoni sp. n. ( Fig. 27 ) are most similar to those of G. lydiae sp. n. ( Fig. 28 ) but differ in the broader anterior sclerotised section of the ductus bursae and the somewhat broader postero-lateral diverticulum of the corpus bursae. Compared to G. proleuca ( Fig. 25 ), the female genitalia of G. bettoni sp. n. have an anteriorly more dilated ductus bursae and a markedly shorter and narrower diverticulum of the corpus bursae.

Distribution. The species is known from Kenya and southern Ethiopia ( Fig. 31 ).

Etymology. The species is named after Charles Steuart Betton, an engineer on the Uganda Railway who collected not only most of the type specimens of this new species but numerous other Invertebrata and small Vertebrata in East Africa.

Figures

FIGURE 31. Distribution map of Gracililema spp.

FIGURES 1–8. Gracililema spp.: adults. Depositories of the specimens: 1 and 4–6 in NHMUK (©The Trustees of NHMUK); 2, 3 and 8 in ANHRT; 7 in ZSM.

FIGURES 17–20. Gracililema spp.: male genitalia. Depositories of the specimens dissected: 17 and 19 in NHMUK (©The Trustees of NHMUK); 18 in ANHRT; 20 in ZSM.

FIGURES 25–29. Gracililema spp.: female genitalia. Depositories of the specimens dissected: 25, 28 and 29 in ANHRT; 26 and 27 in NHMUK (©The Trustees of NHMUK).

FIGURES 21–24. Gracililema spp.: male genitalia. Depositories of the specimens dissected: 21, 23 and 24 in ANHRT; 22 in ZSM.