Zambezia 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 : 55-57

Zambezia Lehmann, Zahiri & Husemann gen. nov.

urn:lsid:zoobank.org:act:733EA950-96E6-450C-A16F-EB2547C81326

Figs 2e, 2f .

Type species: Zambezia madambae (described below), by present designation.

Zambezia madambae has been selected as the type species due to the availability of male and female, its occurrence close to the Zambezi River (only 1.5 km away) and since it has two very rare characters representing a link to basal Metarbelidae , suggesting also that this new genus is older than Lukeniana : first, in the forewing of Z. madambae , one of the longest forks at the base of vein 1A+2A occurs among Metarbelidae , a plesiomorphic character also present in basal species (as defined by Lehmann 2019b), as well as a CuP vein represented by a continuous and strong tube-like fold, partly sclerotized, extending from base of forewing to dorsum in both sexes ( Figs 9c ; 10d ). The latter character is a synapomorphy with Metarbelodes ( Fig. 9c ), but might occur in a few other undescribed genera as well (at present unknown). An intact CuP in forewing is a character found in most Trichoptera and basal Lepidoptera and is only known in basal species of Metarbelidae that occur to the South or close to the Zambezi River ( Lehmann 2019b).

Diagnosis. Species of Zambezia have a short thorn-like process with a truncate tip and a broad, strongly sclerotized, volcano-shaped base at the posterior ventral margin of the valva, slightly above the position of the sacculus (the shape and position of the thorn-like process is an autapomorphy). When a sacculus is present (the sacculus usually appears very narrow or is absent), the thorn-like process is sometimes slightly curved, pointed upward towards the costal end of the valva. The base of the thorn-like process has a broad slit open dorsally with a weakly-sclerotized projection attached to it. Species of Zambezia that occur to the south of or close to the Zambezi River have an additional synapomorphy—a strong, continuous, tubular CuP fold in the forewing; the latter feature is absent in all studied species of Metarbelidae that occur further to the north. This might suggest that Zambezia is a very ancient genus.

Description. Head ( Figs 2c–2f ; Figs 1a–1c ): Rough-scaled; long hair-like scales on fronto-clypeus; paired pits absent from lower fronto-clypeus, but a pair of small conical projections present on lower fronto-clypeus in both sexes (more pronounced in females); projections separate, but close together and between the two large pits that occur behind the labial palpi (usually on a theoretical line between the upper edges of the pits); labial palpi long, almost as long as eye diameter, rarely longer, with three segments. The 2 nd segment longest, 1.5–2.3× longer than basal segment; 3 rd (apical) palpomere shortest, 0.5× length of the 1 st (basal) segment in both sexes. Labial palpi in females sometimes narrower than in males ( Z. madambae ). Male antennae bipectinate; female antennae pectinate, sometimes slightly bipectinate towards the tip of antenna. Dorsal and lateral sides of branches and flagellum scaled in both sexes; branches appear to be generally less scaled in females. In males, tips of branches broader and sometimes slightly spatulate, always densely scaled, scales cream coloured.

Thorax: Densely covered with hair-like scales, slightly finer in females, and lacking ring-like collar; a short scale crest on metathorax. Forelegs and midlegs ochre with long dense hair-like scales. Epiphysis absent in both sexes. Hindlegs with one pair of narrow tibial spurs in both sexes (shorter inner spur at least 0.5 mm long, longer outer spur at least 0.6 mm); rarely, a rudimentary second upper pair occurs, not longer than 0.3 mm, pretarsus with a pair of pulvilli. Forewing upperside largely pattern-free, CuA 2 white or cream-coloured in both sexes; usually not shiny in either sex. Fringe hair-like and long in both sexes. Forewing venation similar in both sexes ( Fig. 9a; 9c; 9d ; 10c, 10d ) with 1A+2A forked at base (one of the longest forks among Metarbelidae occurs in Z. madambae ); CuP (except Z. diredaouaensis ) with a continuous and strong, partly sclerotized tube-like fold extending from base of wing to dorsum in both sexes, an extremely rare character among the Metarbelidae ; CuA 2 originating from hind margin of posterior cell in both sexes; CuA 1, M 3 and M 2 separated and originating from apical angle of posterior cell in both sexes; M 1 originating from distal margin of median cell and more or less close to the base of a relatively large areole in both sexes; R 1 originating from anterior margin of median cell in both sexes; R 2 originating from anterior angle of areole and long-stalked with R 3 +R 4, or R 3 +R 4 are separated from R 2 but have the same basal point ( Z. madambae , Z. darrelplowesi ); R 5 originating from or close to posterior angle of areole in both sexes; Sc more or less parallel to R 1. In hindwing CuA 2 originating from hind margin of posterior cell; CuA 1, M 3 and M 2 from apical angle of posterior cell and are, separated; M 1 and Rs from apical angle of anterior cell, usually stalked in both sexes; with or without a bar from Rs to Sc+R 1; with a small vein in discocellular cell on both fore- and hindwing; fringe with very long cilia in both sexes, 1.1‒2.1 mm in length. Retinaculum and frenulum absent.

Abdomen: With dense hair-like scales and abdominal tuft, usually short, not longer than one-third of abdomen length. Male genitalia ( Figs 14f ; 11a; 11b ; 15a ) with tegumen and vinculum fused, forming firm, narrow ring; lower half of vinculum broader. Uncus large, broad, one uncus lobe ca. 60–80% of valva (lateral view), setose ventrally, sometimes also dorsally. Basal edge of uncus well developed strongly bent or straight at center. Gnathos arms with numerous short pointed processes at their distal ends; rarely upper surface of hand-like end of gnathos arms covered with pointed structures (looking like triangular teeths) dorsally ( Z. madambae ). Gnathos arms not connected by sclerotized basal band ( Shimonia Lehmann & Rajaei 2013 ), but sometimes connected by a thin membranous band basally ( Z. diredaouaensis , Z. madambae , Z. jennyhuntae .) that disappears some days after preparation; usually not bent towards uncus. Valva with one thorn-like postero-ventral process, strongly reduced, always hollow inside and strongly sclerotized, usually bent, rarely setose; from near base of valva and along costal margin (rarely at basal third of costal margin, Z. madambae ) with a large, setose and weakly-sclerotized “inner valva” often attached to an open dorsal slit on the thorn-like process; usually with rounded, rarely ovoid but always short emargination below (less than 30% of the length of valva). Juxta broad and elongate, usually with two acuminate lobes with rectangular processes and a deep posterior emargination. Broad transverse semi-transtilla (often leaf-like, attached to the costa of valva and opposite the vinculum) usually without setae, rarely with many setae ( Z. diredaouaensis ). Sacculus sometimes absent, often reduced to basal third of valva; broad vinculum sometimes opposite saccus, forming a plate as broad as length of saccus ( Z. diredaouaensis ). Saccus broad at base, narrowly triangular or digitate, variable from smaller than to much larger that juxta; usually rounded at tip. Phallus simple, tube-like, long to very long (1.0‒1.5× length of valva), straight, often strongly bent at middle; vesica without cornuti. Female postabdominal structure and genitalia with papillae anales broad; dorsal part obliquely 8-shaped or elliptic in posterior view, covered with short and long setae. Segment 8 setose along its posterior margin and with long setae on its dorsal and anterior parts; sometimes with many setae on the whole segment 8 ( Z. madambae , Z. darrelplowesi ), not emarginate dorso-anteriorly. Ventro-lateral surface of segment 8 with two strongly sclerotized plates (or bands), sometimes large, usually separate along the anterior margin but fused along the posterior margin of the plates, proabably always broadest at middle. Ductus bursae and corpus bursae broad, thinly membranous, corpus bursae often pear-shaped, rarely rounded; always large or very large (equal to or greater than length of segment 8 in lateral view); lacking signa and other sclerotized processeses.

Species richness. Five species are included in Zambezia , all of which are described herein.

Distribution. Species of Zambezia occur in southern and eastern Africa, with one of the most disjunct distributions among Metarbelidae genera: one species occurs on the Harar Plateau (as part of the Somalian Plateau in northeast-central Ethiopia) and four species occur ca. 3.200 km further to the south, but still north of the Limpopo River, on the “Southern African Plateau” (sensu Nyblade & Sleep 2003) and on the adjacent Bvumba Mountains. Within these areas, species of Zambezia appear to have small distributions at elevations above 600 m on mountain ranges or plateau areas in northern Botswana, eastern Zimbabwe and in northeastern Ethiopia (possibly extending their distribution on the Somalian Plateau into northwestern Somalia).

Habitat. See Appendix 1.

Biological traits. The biology of all species of Zambezia is unknown at present.

Etymology. The genus name Zambezia is derived from the Zambezi River, which is one of the two oldest drainage systems on earth, originating ca. 280 Ma ( Key et al. 2015) and representing at present a major boundary to the North for four species of this new genus with rare plesiomorphic and apomorphic characters. The gender of Zambezia is feminine.

Figures

FIGURE 1. a. Zambezia jennyhuntae, holotype, male, Zimbabwe, Manicaland Province, Mutare (formerly Umtali); b. Z. durrellbarnesi, holotype, female, Zimbabwe, Manicaland Province, Bvumba Mountains; c. Z. darrelplowesi, holotype, female, Zimbabwe, Manicaland Province, Mutare (formerly Umtali), Hospital (today Kopje House); d. Metarbelodes umtaliana, holotype, male, Zimbabwe, Manicaland Province, Old Umtali or Umtali (today Mutare).

FIGURE 2. a. Lukeniana butleri, paratype, male, Zimbabwe, Harare Province, Harare, “Fawlty Towers”; b. L. butleri, paratype, female, Zimbabwe, Harare Province, Harare, “Fawlty Towers”; c. L. kollhorsti, holotype, male, Zimbabwe, Manicaland Province, Busi Farm; d. Zambezia diredaouaensis, holotype, male, Ethiopia, Harar Plateau, Dire Daua, today: chartered city of Dire Dawa; e. Z. madambae, holotype, male, Botswana, Chobe District Council, Kasane, Chobe River, Chobe Rapids; f. Z. madambae, paratype, female, Botswana, Chobe District Council, Kasane, Chobe River, Chobe Rapids.

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 10. An intact CuP vein on the forewing is a plesiomorphy (cf. Fig. 9) and occurs only in basal Metarbelidae in northeastern parts of the Republic of South Africa, mainly on the Southern African Plateau, and on the plateau area of Mount Mulanje, only 90 km to the North of the Zambezi River (Lehmann 2019b). Figured are examples of apomorphies in regard to the CuP on forewing (red arrows): a. CuP absent, CuP fold is weak but not continuous in Lukeniana michaelgrzimeki, female, paratype; b. The CuP fold is almost entirely absent in L. rajaeii, male, paratype; c. Zambezia darrelplowesi, female, holotype and d. Z. madambae, male, paratype, both have a strong CuP fold, continuous and partly sclerotized. Images were taken by Dr. Hossein Rajaei (SMNS) in November 2015.

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 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).