Lukeniana obliqualinea ( Bethune-Baker, 1909 ), 2023

Lehmann, Ingo, Zahiri, Reza & Husemann, Martin, 2023, Revision of the Metarbelodes Strand, 1909 genus-group (Lepidoptera: Cossoidea: Metarbelidae) with descriptions of two new genera and 33 new species from high elevations of eastern and southern Africa, Zootaxa 5267 (1), pp. 1-106 : 15-16

Lukeniana obliqualinea ( Bethune-Baker, 1909)

Figs 3b; 3c ; 9b ; 13b ; 11e

Metarbela obliqualinea Bethune-Baker, 1909 . The Annals and Magazine of Natural History (8)3(17): 425.

Material examined. Holotype male, Kenya, Nairobi (today Nairobi Province), 18 February 1906, F. J. Jackson leg., genitalia slide number “Cossid 49 BMNH ” ( Fig.11 ).

Additional specimens: one male, Kenya, Nairobi , February 1928, Dr. van Someren leg., on second label: “van Someren collection 1959–468”, genitalia slide number 26/082012 I. Lehmann ( NHMUK) ; one male, Kenya, same locality, March 1958, R. H. Carcasson leg., genitalia slide number 16/032008 I. Lehmann ( NMK) ; one male, Kenya, Nairobi, Kabete , 25 February 1973, Dr H. Politzar leg., genitalia slide number 15/082014 I. Lehmann ( ZSM) ; one male, Kenya, Nairobi, Loresho Ridge , March 1975, M.P. Clifton leg., genitalia slide number 04/042016 I. Lehmann ( NMK) ; one female, Kenya, Nairobi, Loresho Ridge , April 1975, M.P. Clifton leg., genitalia slide number 19/022008 I. Lehmann ( NMK) ; one female, Kenya, Nairobi, Ngong , February 1954, Mast. Coulson leg., genitalia slide number 27/052015 I. Lehmann ( NMK) ; one male, Kenya, Fort Hall (today Murang’a), April 1967 (or 1957?), P. Sounders (?) leg., genitalia slide number 31/052016 I. Lehmann ( NMK) .

Re-description. Male. Head: Ochre; long and dense hair-like scales between compound eyes; eyes brown with small black spots; antenna 0.50‒0.52 length of forewing, bipectinate, with antennal branches 5 width of shaft, covered with cream-coloured scales laterally; antennal shaft covered with cream-coloured scales dorsally; antennal tips slightly spatulate, with two long scales bending towards apex in male; labial palpi ochre.

Thorax: Patagia and tegulae with long hair-like ochreous scales. A small ochreous crest with intermixed creamcoloured scales on metathorax. Hind legs ochre with fine hair-like scales, shiny; a pair of narrow, long tibial spurs of unequal length, outer spur ca. 1.2 mm, inner spur ca. 1.0 mm in male. Forewing length 13.0‒ 13.5 mm (wingspan 28.5‒31.0 mm). Forewing upperside ochre; termen with sepia striae; oblique terminal line and subterminal lines of sepia, more or less parallel from near apex to end of CuA 1; CuA 2 broad and ivory-yellow, edged sepia above; all remaining veins slightly distinctly coloured ochre in female except 1A+2A; base of forewing in female faint sepia, less visible in males; cilia long, 1.5 mm, shiny ochre. Underside of forewing roughly scaled, light ochre, glossy, costal margin slightly darker and with few striae. Hindwing upperside and cilia cream, glossy, cilia long, 1.5 mm; underside as in forewing but without striae.

Abdomen: Mainly hair-like scales of ochre mixed with cream, shiny, abdominal tuft short, one-fifth of abdomen length. Genitalia ( Fig. 13b ) with uncus lobes almost rectangular, inner edge with a pointed apex, many long and short setae ventrally, emargination between lobes 30–40% of surface of one uncus lobe, basal edge of uncus in ventral view slightly bent at middle; gnathos arms broad and long (slightly longer than basal width of valva), bent, not extending towards upper half of juxta; valvae with a broad base, slightly ovoid, costa with few short setae, sacculus with long and short setae; weakly-sclerotized projection moderately setose, setae long, rectangular tip of the weakly-sclerotized projection touches the thick thorn-like process below, latter with few setae, bent and well developed, hollow with a rounded tip; median sector of valva with short setae on inner side that form rows from base of valva towards an ovoid emargination between weakly-sclerotized projection and thorn-like process and extending 55% length of valva, ventral side of valva not bent at middle. Saccus larger than juxta, broad, triangular, tip broadly rounded. Juxta broad with two acuminate tips, each with a short process at its apex, emargination between tips deep, 90% length of juxta. Phallus not trumpet-like, slightly longer than width of valva, bent near middle, bilobed with a cleft at both ends.

Female. Head: Essentially as described for male; except antenna 0.30 length of forewing, unipectinate, with antennal branches 1.0 width of shaft, antennal tips very short, acuminate, slightly longer than hair-like scales bending towards apex.

Thorax: Essentially as described for male, except length of hindleg tibial spurs ca. 1.3 mm (outer spur) and ca. 0.9 mm (inner spur); forewing length 21.0 mm (wingspan 45.0 mm); forewing including costal margin with sepia or dark ochre striae, termen with sepia lunules; terminal, subtermina, and postmedial lines and sepia-coloured veins rendering reticulate appearance.

Abdomen: Genitalia with papillae anales broad, 8-shaped in posterior view, densely setose with long and short setae. Segment 8 with some short setae on upper surface and along posterior margin; one broad triangular ventrolateral sclerotized band tapering towards base of anterior apophysis covering almost 100% of ventral side of segment 8; another, narrow band behind; the latter narrowest at its centre and completely fused with the other band posteriorly but open anteriorly. Hence, both bands look like two plates partly fused along its posterior margin, but not fused along its anterior margin. Dorso-anterior margin of abdominal plate without an emargination. Posterior apophyses narrow, of equal width and slightly sinuate towards dorsal side of segment 8; anterior apophyses almost straight, slightly shorter than posterior apophyses. Corpus bursae pear-shaped with a shorter ductus bursae both thinly membranous and have no distinct characters.

Diagnosis. Lukeniana obliqualinea is larger and has shorter and broader forewings in both sexes than L. lutztoepferi sp. nov., which also occurs in Nairobi. It has the following unique characters in the male genitalia: the saccus is short and very broad (its width is equal to its length) with a broadly obtuse tip and without a slit which is present in L. lutztoepferi , in which the saccus is longer than wide; and the female postabdominal structure has posterior apophyses that are narrow, with a short posterior end with a wing-like process on each side. The rectangular shape of the uncus and the thick, short thorn-like process resemble those of L. rajaeii which can be easily distinguished from the former two species by the broad, rectangular valvae, that are ovoid in L. obliqualinea and L. lutztoepferi ; the small saccus with a broad plate of the vinculum opposite of the former, this plate is entirely absent in L. obliqualinea and L. lutztoepferi ; the uncus that is not elongate but very elongate in lutztoepferi ; and the largest wing size among males with a very broad and white coloured CuA 2 in the forewing of L. rajaeii . Lukeniana obliqualinea is the closest relative of L. kakamegaensis sp. nov., occurring ca. 250 km further northwest of Nairobi.

Distribution. Lukeniana obliqualinea is known from areas in and around Nairobi, extending ca. 76 km north to Murang’a (south-central Kenya). Nairobi (elevation 1,655 –1,895 m) is situated on the drier East African Plateau ca. 25 km east of the Kenyan Rift. The former rises from the bushland-covered Somalia-Masai plains and belongs to the Afromontane archipelago-like regional centre of endemism (sensu White 1983). Based on its distribution, L. obliqualinea can be classified as an Afromontane near-endemic species (sensu White 1983).

Habitat. See Appendix 1.

Figures

FIGURE 3. a. Lukeniana enaiposha, holotype, male, Kenya, Rift Valley Province, near Lake Naivasha; b. L. obliqualinea, male, Kenya, County Nairobi, Nairobi; c. L. obliqualinea, female, Kenya, County Nairobi, Loresho Ridge; d. L. raymondrevellii, holotype, male, Namibia, Otjozondjupa Region, Ozombanda; e. L. rajaeii, paratype, male, Ethiopia, Southern Nations, Nationalities and Peoples’Region, Gidole; f. L. tubiraensis, holotype, male, Tanzania, Kigoma Region, Tubira Forest.

FIGURE 9. Wing venation of: a. Zambezia darrelplowesi, female, holotype (Zambezia = subgroup G1 in Lehmann 2019b); b. Lukeniana obliqualinea, female, Kenya, County Nairobi, Ngong (Lukeniana = subgroup G3 in Lehmann 2019b); c. Zambezia madambae, male, holotype; d. Z. diredaouaensis, male, paratype; e. Lukeniana tubiraensis, male, holotype; f. Metarbelodes umtaliana, male, holotype (Metarbelodes = subgroup G2 in Lehmann 2019b). The areole (blue arrows) is a possible plesiomorphy (in Lehmann 2019b, p. 24), the continuous CuP fold (red arrows), partly sclerotized, is a very rare apomorphy (in Lehmann 2019b, p. 25) among species of Metarbelidae. It has been found only in species close to or to the South of the Zambezi River. In the same areas an intact CuP on the forewing occurs only in basal species (as defined by Lehmann 2019b, pp. 24 and 25) of Metarbelidae (Lehmann 2019b). The complete loss of the CuP in the forewing is another apomorphy (Lehmann 2019b, p. 322) that occurs in the majority of species of Metarbelidae in theAfrotropical Region and Oriental Region (seeFigure 39).Drawings by I.L.

FIGURE 11. a. Zambezia madambae, holotype, male, Botswana, Chobe District Council, Kasane, Chobe River, Chobe Rapids; b. Z. jennyhuntae, holotype, male, Zimbabwe, Manicaland Province, Mutare (formerly Umtali); c. Metarbelodes umtaliana, holotype, male, Zimbabwe, Manicaland Province, Old Umtali or Umtali (today Mutare); d1. Lukeniana mzuzuensis, paratype, female, Malawi, Northern Region, Mzuzu, Nkho-rongo, female genitalia with ductus bursae and corpus bursae, both thinly membranous and without any structures; d2. Detail of female genitalia of L. mzuzuensis, paratype, with narrow bandson lateroventral surface of segment 8 (cf. red arrows); e. L. obliqualinea, holotype, male, Kenya, County Nairobi, Nairobi (picture taken by Kim Buckmaster, NHMUK, London (picture taken in 1996)..

FIGURE 13. a. Lukeniana enaiposha, holotype, male, Kenya, Rift Valley Province, near Lake Naivasha; b. L. obliqualinea, male, Kenya, County Nairobi, Nairobi; c. L. raymondrevellii, holotype, male, Namibia, Otjozondjupa Region, Ozombanda; d. L. rajaeii, paratype, male, Ethiopia, Southern Nations, Nationalities and Peoples’Region, Gidole; e. L. tubiraensis, holotype, male, Tanzania, Kigoma Region, Tubira Forest; f. L. lutztoepferi, holotype, male, Kenya, County Nairobi, Ololua Forest.