Lukeniana bergsteni Lehmann, Zahiri & Husemann, 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 : 48-49

Lukeniana bergsteni Lehmann, Zahiri & Husemann sp. nov.

Figs 8b, 8c, 8d , 14a , 15c , 18a urn:lsid:zoobank.org:act:DE2DA909-706C-4591-BE9C-11C98A31FBF7

Type locality and repository: Tanzania, the Swedish Natural History Museum , Stockholm ( NRM) .

Material examined. Holotype male, Tanzania, Kilimanjaro Region, Siha District, “ Kilimandjaro, Kibonoto” (today also known as Kibongoto or Kibogoto), 1905–1906, October (written in German as “okt.” for “Oktober” on a small second label), 1905?, Sjöstedt leg., on a third and red label with the number “149 67”, genitalia slide number 15/092009 I. Lehmann ( NRM). Paratypes: one female, 1905–1906, 14 October 1905?, Sjöstedt leg., with one additional information on a second label regarding the locality: “Kibonoto cultural zone” (the latter is written in German as “kulturz.” for “Kulturzone”), on a third and red label with the number “150 67”, genitalia slide number 28/022012 I. Lehmann ( NRM) and the following 25 males from the same locality and collector: three males, 1905–1906, September, 1905? (no genitalia dissection done); one male, 20 September 1905?, genitalia slide number 23/042013 I. Lehmann ( NRM); one male, 20 September 1905?, genitalia slide number 08/022016 I. Lehmann ( NRM); five males, 1905–1906, 24 September 1905? (no genitalia dissection done), including one male that is determined by Sjöstedt as “ Metarbela umtaliana Auriv. ”; one male, 1905–1906, 30 September 1905?, genitalia slide number 01/072012 I. Lehmann ( NRM); one male, 1905–1906, 30 September 1905?, genitalia slide number 20/122009 I. Lehmann ( NRM). No genitalia dissections were done for the following specimens: one male, 1905–1906, 30 September 1905?; six males, 1905–1906, October 1905?; one male, same date with one additional information regarding the locality “Kibonoto cultural zone” (the latter is written in German as “kulturz.” for “Kulturzone”); one male, 1905– 1906, 03 October 1905?; two males, 1905–1906, 04.October 1905?; one male, 1905–1906, 12 October 1905?; one male, 1905–1906, 03 November 1905? One male, Tanzania, Kilimanjaro Region, Hai District, Makoa, 14 February 1952, no collector mentioned, a second label states “ Metarbelodes umtaliana Aur. det. F. Daniel 1955”, genitalia slide number 21/052015 I. Lehmann ( SMNS); one male, “ T. T.O.Afrika” (written in German for “Tanganyika Territorium Ost-Afrika”), today Tanzania, Kilimanjaro Region, Hai District, Makoa, 07–27 January 1959, Lindner leg., genitalia slide number 19/102015 I. Lehmann ( SMNS); five males, same locality, 07–27 January 1959, Lindner leg., no genitalia dissection done, det. I. Lehmann ( SMNS); one male, Tanzania, Arusha Region, Arumeru District, Usa River, 1.170 m, 03 February 1992, L. Aarvik leg., genitalia slide number 24/042012 I. Lehmann ( NHMO); one male, Tanzania, same locality and elevation, 04 February 1992, L. Aarvik leg., genitalia slide number 22/042012 I. Lehmann ( NHMO). Note: Lukeniana bergsteni was determined and published by Aurivillius (1910) as “ Metarbela umtaliana .” Aurivillius stated in the same context that “ M. obliqualinea Baker ” (for Bethune-Baker) is probably identical with umtaliana (both are treated here as separate species and in different genera). The original text is written in German as follows ( Aurivillius 1910, p. 49): “ Arbelidae . Metarbela umtaliana AURIV. Kilimandjaro: 1,000 ‒1,900 m. 44 ♁, 1 ♀. Sept.—Dez. Flug schnell, aber unstätig. Die ♁ kamen im Zelte an′s Licht. Die ♁ stim- men gut mit typischen Stücken aus dem Mashunalande überein. Das bisher unbekannte Weibchen ist dem ♁ ähnlich gefärbt und gezeichnet, hat aber eine Flügelspannung von 42 mm und sehr kurze Kammzähne der Fühler. Die ♁ wechseln in der Grösse zwischen 20 und 30 mm. Nach der Beschreibung scheint M. obliqualinea Baker (An. N.H. (8) 3 p. 425, 1909) identisch mit umtaliana zu sein. ”

Description. Male. Head: Yellow ochre; eyes brown with black spots; antenna 0.50× length of forewing, bipectinate, branches 7× width of shaft, covered with few ivory-yellow scales laterally, shaft covered with ivory-yellow scales dorsally; antennal tips slightly spatulate and with two long scales, bending towards apex; labial palpi ochre.

Thorax: Patagia and tegulae with long hair-like scales of ochre mixed with yellow ochre. A small crest of ivoryyellow on metathorax. Hindlegs ochre with fine hair-like scales, shiny; a pair of narrow, long tibial spurs of unequal length, outer spur ca. 1.1 mm, inner spur ca. 1.0 mm. Forewing length in holotype 14.0 mm (wingspan 31.5 mm); upperside ochre; costal margin sepia with few sepia coloured striae; termen with striae of sepia; bent terminal line and subterminal line of sepia, more or less parallel, from near apex to end of CuA 2 and to middle of CuA 1, respectively; CuA 2 more narrow, pure white, edged sepia above; all remaining veins not distinctly coloured; cilia long, 1.8 mm, yellow ochre, glossy,. Underside of forewing roughly scaled, pale ochre, glossy, costal margin sepia; subterminal line reduced to few faded spots of sepia. Hindwing upperside ivory-yellow or pure white, glossy; cilia same colour as in forewing, 1.8 mm long; underside as in forewing but without striae.

Abdomen: Ochre with ivory-yellow, glossy; abdominal tuft one-fifth of abdomen length. Genitalia ( Figs 14a ; 15c ) with uncus ovoid with narrowly rounded tips, outer edge slightly C-shaped, inner edge rounded at base, lobes densely covered with short setae ventrally, basal edge of uncus strongly bent at middle; gnathos arms long (1.3× basal width of valva), touching coastal margin of valva; valva narrow and elongate ovoid, costa with few short setae; sacculus with few long setae; weakly-sclerotized projection setose, rectangular, shorter in length than thick, short thorn-like process below, latter hollow with a rounded tip, without setae, a second short thorn-like process at its base; median sector of valva with few scattered setae on inner side; short, broad, ovoid emargination extending up to 35% of length of valva between weakly-sclerotized projection and thorn-like process; ventral side of valva not bent at middle; saccus triangular with a rounded tip. Juxta larger than saccus, broad with two acuminate tips, each bearing triangular thorn-like process, emargination between tips 90% of length of juxta. Phallus long, 1.2× length of valva, not trumpet-like, strongly bent near middle, bilobed with cleft at each end.

Female. Head and Thorax: Essentially as described for male, except antenna 0.36× length of forewing, unipectinate, with branches 1.0× width of shaft, antennal tips very short, acuminate, without hair-like scales bending towards apex. Forewing length 21.5 mm (wingspan 45.0 mm). Forewing very broad, almost 1.5× width of male forewing; outer half of forewing faded, with reticulate pattern absent, terminal striae faint; CuA 2 very broad, ivoryyellow mixed with pure white, edged by a broad band of sepia above. More narrow tibial spurs, and hence, less pronounced than in male, outer spur ca. 0.9 mm, inner spur ca. 0.8 mm.

Abdomen: Papillae anales broad, 8-shaped in posterior view, densely setose with long and short setae. On segment 8 only very few long setae along posterior margin; one very broad latero-ventral sclerotized band, triangular with acuminate end towards base of anterior apophysis. This band is covering 60% of ventral side of segment 8 with a broader second band behind it; both only partly fused along posterior margin, not along anterior margin. Dorso-anterior margin of abdominal plate without emargination. Posterior end of posterior apophysis narrow, stick-like, ca. 40% length of apophysis, slightly C-shaped and sclerotized; remaining part of posterior apophysis broader towards tip, slightly bent towards ventral side of segment 8, tip rectangular. Anterior apophysis with rounded tip slightly bent towards ventral side of segment 8. Posterior apophyses slightly longer than anterior apophyses.

Diagnosis. Lukeniana bergsteni resembles L. jankiellandi (see diagnosis of the latter species) but can be distinguished by three characters: (i) the lobes of the uncus are narrowly ovoid (rounded in L. jankiellandi ); (ii) the gnathos arms are long (touching the costa of valva), with (iii) their horizontal part as long as the basal width of valva.

Regarding the statements of Aurivillius (1910: 49) that specimens from Mount Kilimanjaro belong to Metarbelodes umtaliana , it has to be noted that when compared to L. bergsteni , the male genitalia of M. umtaliana differ in the following features: (i) a narrow, finger-shaped saccus; (ii) a shorter emargination of the valva; (iii) no thorn-like appendices at the base of the thorn-like process; (iv) a more curved, narrower, and longer thorn-like process on the valva that is bent downwards from the costa and (v) shorter gnathos arms. Additionally, the forewing upperside shows two remarkable differences: (i) the terminal line is straight in M. umtaliana , but curved (running parallel to the termen) in L. bergsteni and (ii) the marking of vein CuA 2 is broader, particularly the ivory-yellow band, in L. bergsteni compared with M. umtaliana .

In the female post-abdominal structure of L. bergsteni there are two diagnostic characters: (i) the posterior apophyses have a narrow, stick-like posterior end that occupies ca. 40% of their length and is much more sclerotized, while the remaining 60% of the posterior apophysis is broader than the width of the anterior apophyses; (ii) the band-like plate covers 60% of the ventral side of segment 8 with a slightly broader band behind the outer band.

Distribution. Lukeniana bergsteni is known from the southwestern and southern slopes of Mount Kilimanjaro extending ca. 50 km southwest to Usa River ( Tanzania). Mount Kilimanjaro is the highest mountain in Africa (elevation 5,895 m) and is located on the frontier with Kenya in north-central Tanzania. The collecting locality “Makoa” is situated on the southern slopes of Mount Kilimanjaro, just south of Uswaa, and within the “cultural zone” at an elevation of between 1,110 and 1,160 m. The locality “Usa River” is located 20 km east of Arusha ( Tanzania) at an elevation of between 1,198 and 1,225 m. This species is classified as an Afromontane near-endemic species.

Habitat. See Appendix 1.

Etymology. Lukeniana bergsteni is named in honour of the senior curator at the NRM and specialist of aquatic Adephagan families (Coleoptera), Dr. Johannes Bergsten (Stockholm, Sweden), whom we thank for providing samples of Metarbelidae (particularly various types) from the Swedish Museum of Natural History collections, including the holotype of M. umtaliana .

Figures

FIGURE 8. a. Lukeniana jankiellandi, holotype, male, Tanzania, Katavi Region, Luega village; b. L. bergsteni, paratype, male, Tanzania, Kilimanjaro Region, Mount Kilimanjaro, Kibonoto; c. L. bergsteni, paratype, male, Tanzania, Arusha Region, Usa River; d. L. bergsteni, paratype, female, Tanzania, Kilimanjaro Region, Mount Kilimanjaro, Kibonoto; e. L. carolae, holotype, male, Malawi, Central Region, Mount Ntchisi, Ntchisi Forest Reserve; f. L. stevecollinsi, holotype, male, Malawi, Northern Region, Nyika Plateau, Nyika National Park, near Thazima Gate.

FIGURE 14. a. Lukeniana bergsteni, paratype, male, Tanzania, Kilimanjaro Region, Mount Kilimanjaro, Kibonoto; b. L. carolae, holotype, male, Malawi, Central Region, Mount Ntchisi, Ntchisi Forest Reserve; c. L. stevecollinsi, holotype, male, Malawi, Northern Region, Nyika Plateau, Nyika National Park, near Thazima Gate; d. L. butleri, paratype, male, Zimbabwe, Harare Province, Harare, “Fawlty Towers”; e. L. kollhorsti, holotype, male, Zimbabwe, Manicaland Province, Busi Farm; f. Zambezia diredaouaensis, holotype, male, Ethiopia, Harar Plateau, Dire Daua, today: chartered city of Dire Dawa.

FIGURE 15. Examples of male genitalia in lateral view: a. Zambezia madambae, paratype, with extremely small thorn-like process and small weakly-sclerotized projection (red arrows); b. Lukeniana timdavenporti, paratype, with strongly bent ventral edge of valva and well developed thorn-like process (red arrows); c. L. bergsteni, paratype, without strongly bent ventral edge of valva and two thorn-like processes (red arrows); d. L. butleri, paratype, with many long setae on valva that appear to be black in colour and one thorn-like process (red arrows).

FIGURE 18. a. shows two fronto-clypeal projections (red arrows) of Lukeniana bergsteni, female, paratype. The projections are close together, that means the distance between the projections is ca. 1.0–1.5× of the width of the pit behind the labial palpus, and they are more pronounced in females than in males of Lukeniana and Zambezia. The two projections are more widely separated in species of Mountelgonia Lehmann, 2013, that means the distance between the projections is ca. 2.5–3.5× of the width of the pit behind the labial palpus. b. shows an enlargement of one fronto-clypeal projection. c. shows four branches of the female antenna. The pictures were taken with a Scanning Electron Microscope at ZFMK by Karin Ulmen in March 2012.