Lukeniana mikerobertsi 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 : 42-44

Lukeniana mikerobertsi Lehmann, Zahiri & Husemann sp. nov.

Figs 7b, 7c, 7d , 17c

urn:lsid:zoobank.org:act:C99E4929-5834-4FBA-9999-C5EA0429B2C0

Type locality and repository: Kenya, Zoological Research Museum Alexander Koenig , Leibniz-Institute for the Analysis of Biodiversity Change ( LIB / ZFMK) .

Material examined. Holotype male, Kenya, Laikipia County, Laikipia East sub-county, Lolldaiga Hills Ranch Limited, “Kambi ya Simba”, Site 2, 01 March 2016, J.M. Mathiu, I. Lehmann, M. Roberts leg., no genitalia dissection done ( ZFMK). Paratypes: one male, Kenya, same locality as holotype, Site 1 (light-trap below one of biggest Juniperus (Cupressaceae) trees with dbh of 109 cm), 01 March 2016, J.M. Mathiu, I. Lehmann, M. Roberts leg., genitalia slide number 28/032016 I. Lehmann ( ZFMK); one male, Kenya, same locality as holotype, “Three Dams”, Site 4, 02 March 2016, J.M. Mathiu, I. Lehmann, M. Roberts leg., genitalia slide number 26/032016 I. Lehmann ( NMK); one male, Kenya, Laikipia County, Laikipia East sub-county, Mpala Research Centre (= MRC), Site 1 (eastern part of MRC), 04 March 2016, I. Lehmann leg., no genitalia dissection done ( NMK); one male, Kenya, Mpala Research Centre ( MRC), Site 1 (eastern part), 04 March 2016, I. Lehmann leg., genitalia slide number 01/042016 I. Lehmann ( ZFMK); one male (with darker forewings), Kenya, same locality, Site 1, I. Lehmann leg., genitalia slide number 21/072016 I. Lehmann ( ZFMK); one male, Kenya, same locality, Site 1, 04 March 2016, I. Lehmann leg., no genitalia dissection done ( MNHN); one male, Kenya, same locality, Site 1, 05 March 2016, I. Lehmann leg., no genitalia dissection done ( ZMH); seven males, Kenya, same locality, Site 1, 05 March 2016, I. Lehmann leg., no genitalia dissections done ( NRM and first authors’ private collection); one female, Kenya, MRC, Site 1, 04 March 2016, I. Lehmann leg., genitalia slide number 02/042016 I. Lehmann ( NMK); one female, Kenya, same locality, Site 1, 04 March 2016, I. Lehmann leg., genitalia slide number 23/042016 I. Lehmann ( SMNS); one female, Kenya, same locality, Site 1, 05 March 2016, I. Lehmann leg., no genitalia dissection done ( NMZB); one female, Kenya, Site 2, 06 March 2016, I. Lehmann leg., no genitalia dissection done ( RMCA); one female, Kenya, same locality, Site 2, 07 March 2016, I. Lehmann leg., no genitalia dissection done ( NRM); one male, Kenya, Laikipia County, Laikipia East sub-county, Lolldaiga Hills Ranch Limited, house of General Ranch Manager Harry Hanegraaf, 2,100 m, March 2017, M. Roberts leg., no genitalia dissection done ( NHMUK); one male, Kenya, Laikipia county, Laikipia East sub-county, Mogwooni Ranch, Kiluma, 1,900 m, April 2017, A.G. Roberts, M. Roberts leg., genitalia slide number 02/072017 I. Lehmann ( NHMUK).

Description. Male. Head: Light cream mixed with ochre and sepia coloured hair-like scales, not shiny; between eyes long, dense hair-like scales in both sexes; eyes golden-ochre with light brown patches; antenna 0.52‒0.58 length of forewing, bipectinate, with branches 6.5 width of shaft, branches covered with cream scales laterally, shaft with cream scales dorsally; antennal tips of branches slightly spatulate, densely scaled, bending towards apex; labial palpi dark ochre.

Thorax: Patagia and tegulae without shiny scales, with long hair-like scales of light ochre mixed with light grey and pure white scales. A small crest of light ochre mixed with pure white on metathorax. Hindlegs pale ochre mixed with single scales of sepia with longer fine hair-like pale ochre shiny scales; one pair of narrow, long tibial spurs present, outer spur ca. 1.0 mm (outer spur), inner spur ca. 0.9 mm. Forewing length of holotype 11.0 mm (wingspan 24.0 mm), of paratype from Lolldaiga Hills Ranch 10.5 mm (wingspan 23.0 mm), of paratype from MRC 11.5 mm (wingspan 24.5 mm). Forewing upperside pale-cream mixed with white and pale ochre, glossy towards termen; costal margin ochre with some black or sepia-coloured scales restricted to near base of wing in male; distinctly coloured striae of sepia or pale ochre forming an almost continuous subterminal line and sometimes postmedial line running nearly parallel in upper half of wing to subterminal line; along termen a broad band of pale ochre, small spots of sepia at ends of all veins forming a continuous narrow line along termen from apex to CuA 2; below CuA 2 a broad pure white band, narrowly edged in sepia above; all remaining veins not distinctly coloured except 1A+2A narrowly sepia and sepia coloured on lower median vein of discal cell; from close to centre of lower median vein occur two nearly continuous narrow lines of sepia towards dorsum; cilia very long, 1.7–2.0 mm, pale ochre or almost white, shiny. Underside of forewing roughly scaled, pale ochre, glossy; costal margin ochre; scattered scales of sepia near base of wing. Hindwing upperside white, glossy; cilia as in forewing; underside as in forewing.

Abdomen: Cream and pale ochre, glossy; abdominal tuft short, ca. 25% of abdomen length. Genitalia ( Fig. 17c ) with rounded uncus lobes, bearing both short and long setae ventrally; gnathos arms long, at least 1.3 basal width of valva, not bent towards uncus; valva subrectangular, base only slightly wider than width of valva, costa with few long setae; sacculus very broad (30‒45% of width of valva) with short setae; weakly-sclerotized projection setose with rectangular tip, longer than single thorn-like process; the latter narrow, very long (as long or almost as long as basal width of valva and much longer than length of juxta), usually extending above sclerotized projection, sharply bent and well developed, hollow with an acuminate tip, few setae sometimes near base of thorn-like process; median sector of valva with few short setae on inner side forming no more than two rows from base of valva towards a short, ovoid emargination; latter extending 30% of length of valva between weakly-sclerotized projection and thorn-like process; ventral side of valva straight. Saccus finger-shaped, broad, truncate. Juxta 2.5–3.0 larger than sacccus, much broader than base of saccus, with two acuminate tips, each bearing a short process; emargination between tips deep, extending ca. 90% of length of juxta. Phallus trumpet-like, slightly longer than width of valva, not bent near middle, bilobate with a cleft at each end.

Female. Head: Essentially as described for male, except, compound eyes light brown with small black patches; antenna 0.40 length of forewing, unipectinate, with branches 1.3 width of shaft; tips with one or two long narrow scales; labial palpi light ochre, slightly longer than eye diameter.

Thorax: Patagia and tegulae with long, hair-like, light ochre scales, not mixed with light grey or pure white scales as in male. Metathoracic crest exclusively light ochre; tibial spurs ca. 1.3 mm (outer spur) and ca. 1.0 mm (inner spur). Forewing length of paratype 15.0 mm (wingspan 32.5 mm). Forewing upperside largely ochre mixed with sepia scales; entire costal margin mixed with sepia scales; subterminal and postmedial lines absent; line of sepia formed by small spots at along termen absent or less pronounced than in male; coloration of 1A+2A likewise less pronounced; two nearly continuous narrow lines of sepia from close to centre of lower median vein towards dorsum absent; cilia 1.2–1.5 mm; sepia along entire costa; hindwing upperside pale cream;

Abdomen: Abdominal tuft ca. 15% of abdomen length. Genitalia with papillae anales narrow, 8-shaped in postero-dorsal view, densely setose with long and short setae. Segment 8 with long scattered setae on entire surface, with short setae along posterior margin and on dorsal surface. Two strongly sclerotized plates latero-ventrally, forming a hollow half disc-shaped band broadly rounded at its end, the latter well below ventral edge of segment 8 in lateral view. Inner part of lower band smaller than outer; band appearing rectangular towards anterior apophyses, and covering entire width of ventral side of segment 8. Antero-dorsal margin of abdominal plate without emargination, with one pair of short peculiar setae, each with a broad sclerotized base. Posterior apophyses slightly bent upward at middle with a base 4.0 broader than that of anterior apophyses, posteriorly without thorn-like projection or uneven dorsal edge. Anterior apophyses slightly bent near middle, shorter than posterior apophyses. Ductus bursae narrow, shorter than corpus bursae, both thinly membranous, lacking processes or distinct sclerotized features; corpus bursae subspherical, 2.5–3.0 as wide as length of anterior apophysis; ductus bursae short, only 1.3 longer than anterior apophysis.

Diagnosis. The narrow, long, delicate thorn-like process, the shape of the valvae, and the pale ochre terminal band on the forewing upperside resemble those of L. georgeadamsoni . The two species can be distinguished by the following characters:: (i) the very long abdominal tuft in the male (ca. 40% of abdomen length) of L. georgeadamsoni is much shorter in L. mikerobertsi , ca. 25–30% of abdomen length; (ii) L. mikerobertsi is generally smaller; (iii) the ratio of antennal length: forewing length is greater in L. mikerobertsi ; (iv) the forewing upperside is pale orangeyellow and the entire forewing is without distinctly coloured striae in L. georgeadamsoni , but is a mixture of pale cream coloration and pale ochre with distinctly sepia or pale ochre striae forming a nearly continuous subterminal line and sometimes a postmedial line parallel to it in the upper half of the wing in L. mikerobertsi ; and (v) the juxta is large in L. mikerobertsi , as long as the basal width of valva, 2.5–3.0 larger than the saccus, but in L. georgeadamsoni the juxta is slightly less than half as long as the basal width of the valva, and only 1.5–2.0 as large as the saccus.

The thorn-like process in L. mikerobertsi is the second longest among species of Lukeniana , exceeded only by that of L. tubiraensis . However, the dark ochre upperside of the forewings, nearly rectangular uncus lobes, stout gnathos arms, and broad base of the vinculum forming a ventral plate in L. tubiraensis all separate it from L. mikerobertsi .

One character in the female postabdominal structure shared with L. michaelgrzimeki is a strongly sclerotized ventral plate that covers the entire ventral side of segment 8 (in ventral view). A character unique to L. mikerobertsi is that the rectangular end of the ventral plate is well below the base of the anterior apophyses (see diagnosis of L. michaelgrzimeki ).

Distribution. Lukeniana mikerobertsi is known from the Laikipia Plateau, east of the central Kenya Rift in northwest-central Kenya. The collecting sites are situated within the Afromontane archipelago-like regional centre of endemism at “Kambi ya Simba” (elevation 2,165 m and 2,160 m), located in dry Single-dominant Afromontane forest, ( Figs 22e; 23a; 23b ). This species can be classified an Afromontane near-endemic species. Ten male and five female paratypes were collected within the Mpala Research Centre (elevation range 1,659 –1,715 m) which lies on the northwestern part of the Laikipia Plateau and 40‒45 km northwest of the lower northwestern slopes of Mount Kenya within the Afromontane archipelago-like regional centre of endemism ( Figs 23c; 23d ).

Habitat. See Appendix 1.

Etymology. The species is named in honour of Michael (Mike) Boyce Roberts (born in Nairobi in 1981), the General Manager of the Ole Naishu Ranch ( Kenya). As a member of the Lepidopterists’ Society of Africa, he has conducted many field surveys of butterflies in Kenya (cf. Collins & Libert 2013), Tanzania, and northwest Zambia. The first author is very grateful to Mike for leading valuable fieldtrips in the Lolldaiga Hills in March 2016, May and June 2017, as well as various exciting light-trappings among very old trees, herds of elephant, buffalo, and nearby hyenas.

Figures

FIGURE 7. a. Lukeniana georgeadamsoni, holotype, male, Kenya, Eastern Province, Game Ranch of Dr. David Hopcraft, 1.5 km west from the Lukenia Hills; b. L. mikerobertsi, holotype, male, Kenya, County Laikipia, Lolldaiga Hills Ranch and Wildlife Conservancy, “Kambi ya Simba”; c. L. mikerobertsi, paratype, male, Kenya, County Laikipia, Mpala Research Centre, Site 1; d. L. mikerobertsi, paratype, female,

FIGURE 17. a. Lukeniana utaheidenreichae, holotype, male, Mozambique, Manica Province, Barr De Chikamba Real; b. L. georgeadamsoni, holotype, male, Kenya, Eastern Province, Game Ranch of Dr. David Hopcraft, 1.5 km west from the Lukenia Hills; c. L. mikerobertsi, holotype, male, Kenya, County Laikipia, Lolldaiga Hills Ranch and Wildlife Conservancy, “Kambi ya Simba”; d. L. andreashempi, holotype, male, Tanzania, Arusha Region, Mount Meru; e. L. kakamegaensis, holotype, male, Kenya, Western Province, Kakamega; f. L. jankiellandi, holotype, male, Tanzania, Katavi Region, Luega village.

FIGURE 23. a. Habitat of Zambezia jennyhuntae: The nearly evenly aged structure of the tree layer in a drier type of open miombo woodland dominated by Julbernardia globiflora (Benth.) Troupin (Caesalpiniaceae) and Brachystegia spiciformis Benth. (Caesalpiniaceae) close to Marondera (Zimbabwe) is due to anthropogenic activity since 1929. The young stand in the image is the result of protection of the miombo since the late 1960s. Photo by Rhett Butler (Harare), October 2015. b. Habitat of Zambezia durrellbarnesi: View from the summit of the Bvumba Mountains taken from Castle Beacon (1.911 m) in May 1969 by the late botanist Darrel Plowes (Mutare, Zimbabwe). Beyond the flowering Aloe arborescens Mill. (Aloaceae) (right) is the Burma Valley below and on the southeast side, the high hill in the middle distance is Leopard Rock, a so called “granite bornhardt”. Where the high Bvumba ground drops sharply down into the Burma Valley (730–880 m, both part of the post-African surface developing since 30–25 Ma) in the right centre of the picture, the Witchwood Valley forest or Bungu Forest, begins. The forests seen towards the Burma Valley and Leopard Rock are mixed submontane forests with the highest tree species diversity recorded for Zimbabwe (Müller 2006). Within a few kilometers an older erosion surface (possibly African Surface) may be preserved on Castle Beacon (Lister 1987; Andy Moore pers. com. to I.L. in 2016). The row of hills in the background forms the border with Mozambique and still belongs geomorphologically to the Bvumba Mountains.