Shimbania tanaensis, 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 tanaensis sp. nov.

Figs 1c, d , 8b , 12a

Material examined.

Holotype male, Kenya, [North Coast], [Tana River County], [just south of] Mchelelo Camp [KWS], Riverine Forest , 01°52'59"S, 40°08'20"E, 251 m [incorrect altitude that is 45 m], Mercury Vapor Light, 17-18 March 1999, [Dr.] K. Maes [leg.], genitalia slide number 07/012009 I. Lehmann (NMK) . Paratypes: one male, same label data, genitalia slide number 03/022009 I. Lehmann (NMK); one male, Kenya, [Makueni County], Kibwezi , 08-14 May 1995, Dr. Politzar leg., genitalia slide number 25/072009 I. Lehmann (MWM) ; one male, Kenya, [North Coast], [Mombasa County], Shimo la Tewa [also Shemu-li-Tewa], 06 April 1932, Stoneham [leg.?], genitalia slide number 13/012008 I. Lehmann (NMK) .

Description.

Head: olive-brown, short scales, glossy; eyes black; a pair of pits present on lower fronto-clypeus (also in paratypes); pits behind labial palpi small (also in paratypes); antenna 0.35 length of forewing, bipectinate, branches 3.6 × width of shaft, not scaled, widely separated at base, 2 × width of branch; shaft densely covered with cream scales dorsally; labial palpi dark chestnut.

Thorax: Patagia is olive, forming a collar ring, scales with light grey tips; tegulae with long hair-like chestnut scales with a light vinaceous glint. Metathorax with small crest of cream scales, crest chestnut at center with a light vinaceous glint. Hind legs olive-cream with fine hair-like scales with light grey tips, on lower part of tarsus sepia dorsally; two pairs of long tibial spurs of unequal width and length, upper pair narrow ca. 1.6 mm and 1.4 mm, lower pair of spurs broader ca. 1.0 mm and 1.3 mm long. Forewing length is 23.0 mm and wingspan 51.0 mm in holotype (wingspan 47.0-54.0 mm in paratypes). Forewing upperside brown-olive on inner half and olive-grey on outer half with a light golden glint; below first half of 1A+2A a large dark chestnut patch; forewing without many narrow olive lines, all veins narrowly sepia; a weak subterminal patch, V-shaped, possibly only visible in fresh males, from below costal margin to near end of CuA1; termen without striae or lunules; cilia short, 1.1 mm, olive with grey tips. Underside of forewing is light grey-olive with a golden glint. Hindwing upperside is light grey-olive, glossy, with weak light brown lines; cilia as in forewing; underside as in forewing but with weak brown lines.

Abdomen: Mainly light olive mixed with cream, glossy; abdominal tuft light olive, medium long, 1/4 length of abdomen. Genitalia with long uncus, 70% of length of whole gnathos, with a narrow graben-like surface ventrally. Gnathos has gnathos arms that are large, one arm 50% the size of valva; upper part of gnathos arm is a long band (if compared to S. baginerichardi sp. nov.) as long as 65% of basal width of valva, the lower part of the gnathal arm is large, and it does touch or almost touch the other arm (ventral view), of broad triangular shape with a pronounced thorn-like structure and with its base 90% of the basal width of valva, with several smaller thorns along its dorsal edge; the gnathal arms are connected ventrally by a narrow sclerotized band that is as broad as 25% of the transtilla and is widely bifurcated in the middle. The Gnathos arms end well above the dorsal edge of transtilla. The valva is elongated with a dorsal edge of 2.0 × the length of uncus, rectangular, ventral edge of valva strongly bent inwards at 60% of length with a tip that is broadly rounded; sacculus long, narrow, weakly sclerotized, 60% of length of ventral edge of valva; saccus absent; juxta well developed, with two broadly ear-shaped lobes with a broadly V-shaped emargination in between that is 60% the length of juxta, tips of lobes pointed. Phallus very large, as broad as 40% of basal width of valva and 30% longer than costal width of valva, only slightly S-shaped and bent upwards at tip distally, vesica without cornuti.

Female. Unknown.

Diagnosis.

Shimbania tanaensis sp. nov. can be separated from all other congeners by the large gnathal arm that is at least 50% the size of valva with its upper part representing a long band that is as long as 65% of basal width of valva and with its lower part that does touch or almost touch the other arm (in lateral view both gnathal arms touch each other in holotype and all paratypes); the latter are well separated in S. baginerichardi sp. nov. where the band is only 40% of the basal width of valva and the gnathal arm is not larger than 40% of the valva. Furthermore, the gnathal arms are connected ventrally by a sclerotized band that is narrowly bifurcated in the middle in S. baginerichardi sp. nov., but widely bifurcated in S. tanaensis sp. nov. In addition to these characters, the valva is more elongated with a dorsal edge of 2.0 × the length of uncus and the ventral edge that is suddenly strongly bent inwards at 60% of the ventral edge, while in S. baginerichardi sp. nov. the dorsal edge is 1.3 × the length of uncus and the ventral edge is not suddenly strongly bent inwards, but oblique towards tip. One common character with S. baginerichardi sp. nov. is the narrow ventral base of the vinculum with 1.2 × the width of the upper part of vinculum. Although the width is similar in both species the vinculum is straight cut at lower end in S. tanaensis sp. nov. but oval in S. baginerichardi sp. nov. A similar species in regard to the large size of the lower gnathal arm and elongated valvae but with a pointed tip is S. pwaniensis sp. nov. The most striking difference to S. tanaensis sp. nov. is the broad and wavy vinculum at its lower end (cf. diagnosis of S. pwaniensis sp. nov. below).

Distribution.

Shimbania tanaensis sp. nov. is known from coastal areas north of Mombasa to the Tana River and westwards to Kibwezi, a locality where various coastal Metarbelidae occur. Hence, this species is present in the Somalia-Masai regional centre of endemism as well as in the Zanzibar-Inhambane regional mosaic. Based on its distribution, S. tanaensis sp. nov. can be classified as an endemic species to eastern Kenya.

Etymology.

Shimbania tanaensis is named for the Tana River (Kenya) with its distinct riparian forest patches, including one forest patch that is the habitat of the holotype and one paratype, and to remember my (I.L.) Diploma Thesis in Kenya with my first collection of leaves from the rare Kenyan endemic riparian tree species Populus ilicifolia Rouleau ( Salicaceae ) along the Tana River, near Hola, in 1989.

The gender of the new species name is feminine.

Figures

Figure 1. a. Shimbania baginerichardi sp. nov., holotype, male, Kenya, Kwale County, Shimba Hills National Reserve; b. S. budaensis sp. nov., holotype, male, Kenya, Kwale County, Buda Forest Reserve; c. S. tanaensis sp. nov., holotype, male, Kenya, Tana River County, Mchelelo Camp, close to the Tana River; d. S. tanaensis sp. nov., paratype, male, Kenya, Mombasa County, Shimo la Tewa.

Figure 8. Male and female genitalia in a pressed condition below glass: a. Shimbania baginerichardi sp. nov., holotype, male, Kenya, Kwale County, Shimba Hills National Reserve; b. S. tanaensis sp. nov., paratype, male, Kenya, Mombasa County, Shimo la Tewa; c. S. budaensis sp. nov., holotype, male, Kenya, Kwale County, Buda Forest Reserve; d. S. pwaniensis sp. nov., holotype, male, Tanzania, Pwani Region, road from Dar es-Salaam to Chalinze, near the railway-crossing, ca. 2 km from the Ruvu River.

Figure 12. Aedeagus (phallus) of a. Shimbania tanaensis sp. nov., paratype, male, Kenya, Tana River County, Mchelelo Camp close to the Tana River; b. Morondavania mineti sp. nov., paratype, male, Madagascar, Western Region, north of Morondava, western part of Marofandilia Forest. The size of the aedeagus of the species of these sister-genera is among the largest in Metarbelidae.