Shimbania kaguruensis, Lehmann & Dalsgaard, 2023

Lehmann, Ingo & Dalsgaard, Thure, 2023, Revision of Saalmulleria Mabille, 1891 (Lepidoptera, Metarbelidae) from Madagascar with the description of three new genera and fifteen new species, Evolutionary Systematics 7 (1), pp. 133-182 : 133

Shimbania kaguruensis sp. nov.

Figs 2c , 9b

Material examined.

Holotype male, Tanzania, Morogoro Region, Kaguru Mountains [also called Ukaguru Mountains], “forêt alt.: 1900 m " [> 1.800 m = upper montane forest, cf. Pócs 1976], 26 April 2005, Ph. Darge [leg.], genitalia slide number 05/122008 I. Lehmann (MWM).

Description.

Head: ventrally brownish-olive (without any chestnut colour), the rest is pale olive-buff (cf. Shimbania puguensis sp. nov. and Shimbania pwaniensis sp. nov. that have dark chestnut scales on the head), short scales with cream tips, not glossy; eyes light brown-olive with few small black spots and surrounded by long hair-like scales of brownish-olive ventrally without a glint; a pair of pits is rudimentary on lower fronto-clypeus; pits behind labial palpi are slits; antenna short, 0.30 length of forewing, bipectinate, shaft narrow, branches long with 4.5 × width of shaft, not scaled, all branches are widely separated at base, at least 2 × width of branch; shaft densely covered with ivory-yellow scales dorsally; labial palpi long, almost as long as eye-diameter, buffy-olive.

Thorax: Patagia pale olive-buff, forming a collar ring, few scales with light grey tips; tegulae with long hair-like brownish-olive scales (without any chestnut colour), glossy. Metathorax has a crest of pale olive-buff scales with brownish-olive center. Hind legs pale olive-buff with fine hair-like scales with light grey tips, on lower part of tarsus brownish-olive dorsally; two pairs of tibial spurs of unequal width and length, upper pair narrow ca. 1.0 mm and 1.2 mm, lower pair slightly broader and ca. 0.9 mm and 1.1 mm long. Forewing length 21.0 mm and wingspan is 44.0 mm in holotype. The whole forewing upperside is pale olive-buff with a light golden glint; below first half of 1A+2A a weak brownish-olive patch; forewing with few weak narrow dark olive lines from costa to dorsum, veins not distinctly marked; a large and deep olive subterminal patch, broadly oval-shaped, from R4 to near middle of CuA1; termen without lunules; cilia short, 1.0 mm, pale olive-buff with grey tips. Underside of forewing is cream-buff with weak brownish-olive lines and a golden glint. Hindwing upperside is pale olive-buff with a light golden glint; cilia as in forewing; underside as in forewing.

Abdomen: Pale olive-buff mixed with ivory-yellow hair-like scales with a glint; abdominal tuft with hair-like scales of pale olive-buff and ivory-yellow, medium long, 1/4 length of abdomen. Genitalia with long uncus, 70% of length of whole gnathos, narrow graben-like surface ventrally absent. Gnathos has gnathos arms that are large, one arm 30% the size of valva; upper part of the gnathos arm is a long band, as long as 65% of basal width of valva, the lower part of the gnathal arm does not touch the other arm, it is of broad triangular shape with a pronounced thorn-like structure and with its base 50% of the basal width of valva, a strongly serrate dorsal edge is present; the gnathal arms are connected ventrally by a narrow sclerotized band that is as broad as 25% of the transtilla and is widely bifurcated at the middle. The Gnathos arms end above the dorsal edge of the transtilla. The valva is broadly triangular with a dorsal edge of 2.0 × the length of uncus, ventral edge of valva slightly S-shaped with a tip that is broadly pointed; sacculus not pronounced, short and narrow, sclerotized, 30% of length of ventral edge of valva; juxta well developed, with two broadly rounded lobes and a narrowly V-shaped emargination in between is 80% the length of juxta, tips of lobes broadly rounded. Phallus unknown (broken near its basal end).

Female. Unknown.

Diagnosis.

Shimbania kaguruensis sp. nov. can be separated from all other congeners by its small wing size, the shortest antennae (also in relation to the forewing length) among all species presented here with a remarkable narrow shaft and widely separated long narrow branches; the genitalia is similar to S. pwaniensis sp. nov., both species share two characters in common, namely the absence of a graben-like surface on the uncus ventrally and the wavy shape of the upper part of vinculum (but not on the ventral part like in S. pwaniensis sp. nov.). The shape of vinculum (viewed ventrally) is very rounded in S. kaguruensis sp. nov., but broadly oval in S. pwaniensis sp. nov. In the latter species, the larger gnathal arms are of triangular shape and have only one thorn-like appendice in front of an entirely straight dorsal edge while in S. kaguruensis sp. nov. the gnathal arms bear a long and a small thorn-like appendice in front of a strongly serrate dorsal edge. Furthermore, S. pwaniensis sp. nov. has a very contrasting and much darker forewing pattern with a larger subterminal patch; its forewing is also more elongated. Nevertheless, due to the common characters in the male genitalia mentioned above, a closely related species of S. kaguruensis sp. nov. is S. pwaniensis sp. nov.

Distribution.

Shimbania kaguruensis sp. nov. is known from an upper montane forest at 1.900 m in the Kaguru Mountains, the highest altitude recorded for any species of Shimbania (cf. the closely related S. pwaniensis sp. nov. that is recorded from an altitude of 37 m). Noteworthy, the upper montane forests (> 1.800 m altitude) of the Kaguru Mountains have the most endemic-rich flora ( Lovett 1998) if compared to the forests below an altitude of 1.800 m. The Kaguru Mountains belong to the "central Eastern Arc Mountains" ( Lovett 1998) and are located ca. 220 km inland from the Indian Ocean coastline comprising a natural forest area of 184 km2 ( Newmark 2002) with an altitudinal range of montane forest from 1.500-2.250 m ( Burgess et al. 1998). Shimbania kaguruensis sp. nov. is classified here as a montane forest species of drier forest that is endemic to the central Eastern Arc Mountains, in particular to the Kaguru Mountains, and occurs also most probably, e.g. in the Rubeho Mountains to the Southwest, in the Kiboriana Mountains to the West and in the Nguru Mountains to the Northeast. Since 90% of the original natural forest cover is already lost in the Kaguru Mountains ( Newmark 2002), S. kaguruensis sp. nov. is potentially threatened.

Etymology.

Shimbania kaguruensis is named for the Kaguru Mountains (Tanzania) that are among the three least scientifically studied Eastern Arc Mountains and among the two mountains with the highest losses of original forest cover in the last 200 years (90%) and among the four mountains with the most pronounced dry season ( Newmark 2002).

The gender of the new species name is feminine.

Figures

Figure 2. a. Shimbania pwaniensis sp. nov., holotype, male, Tanzania, Pwani Region, road from Dar es-Salaam to Chalinze, near the railway crossing, ca. 2 km from Ruvu River; b. S. puguensis sp. nov., holotype, male, Tanzania, Pwani Region, Pugu Forest; c. S. kaguruensis sp. nov., holotype, male, Tanzania, Morogoro Region, Kaguru Mountains; d. S. mbarikaensis sp. nov., holotype, male, Tanzania, Morogoro Region, Mbarika Mountains, south of Mahenge Forest; e. S. kerstinhempae sp. nov., holotype, female, Tanzania, Arusha Region, Usa River, Danish Volunteer Training Centre.

Figure 9. a. Shimbania puguensis sp. nov., paratype, male, Tanzania, Pwani Region, Kisarawe Forest; b. S. kaguruensis sp. nov., holotype, male, Tanzania, Morogoro Region, Kaguru Mountains; c. S. mbarikaensis sp. nov., holotype, male, Tanzania, Morogoro Region, Mbarika Mountains (also called Mbaraka Mountains), south of Mahenge Forest; d. S. wanjakinuthiaae sp. nov., holotype, male, Republic of South Africa, Province KwaZulu-Natal, ca. 5 km north of Hluhluwe, probably collected on Hluhluwe Farm.