Morabia distinctaria László & Hausmann 2022, comb. n.
Creators: name: László, Gyula M.
name: Hausmann, Axel
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Lepidoptera
Geometridae
Morabia
Morabia distinctaria

description: Morabia distinctaria (Joannis, 1915), comb. n.
(Figs 13–14, 32, 39)
Synopsia distinctaria Joannis (1915): 10. Syntypes 2 females, Mauritius, Curepipe, coll. MNHN.
Material examined. Mauritius. 2 males, Mt. Cocotte, on track on first big bend, swampy woodland, 718m, 4.xii.2005, 20°26’27”S, 57°28’34”E, MV, leg. Clive R. Turner, ANHRT:2021.4, gen. slide No.: LG 5521; 1 female, Brise Fer old plot, 80% restored endemic Sideroxylon forest, conservation area, 550m, 13.xii.2005, 20°22’S, 57°26’E, MV, leg. Clive R. Turner, ANHRT: 2021.4, gen. slide No.: LG 5522 (ANHRT); 1 female, Mauritius, G. Antelme / Pres. By Imp. Bur. Ent. Brit. Mus. 1926-376, gen. slide No.: NHMUK 10317355 (prepared by László); 1 male, Mauritius, 26. 21. / Joicey Bequest. Brit. Mus. 1934-120 (NHMUK).
Diagnosis. Morabia distinctaria (Joannis, 1915) shows the typical Morabia wing pattern characterized by the brownish-grey ground colour, the fine, but sharply defined, subcostally angled ante- and postmedial lines of the forewing and the conspicuous large black subapical blotches on the underside of the wings, but is distinguished from its continental congeners by the narrower, more pointed forewing and more sharply angled postmedial line. Based on genital morphology, it is closest to the Madagascan M. hero (Viette, 1971); the differential characters between the two species are discussed under the latter taxon. Based on the similar configuration of the male genitalia, M. distinctaria, M. hero and M. herbuloti (Orhant, 2003) represent a distinct lineage within the genus, characterised by the following features: the uncus is narrow and finger-like, the costal arm of the valva is short and stout, the valva is more heavily sclerotized and the vesica bears a markedly shorter and thinner cornutus compared to the continental taxa. In the female genitalia, the main distinctive features of the M. distinctaria -lineage are expressed by the considerably more heavily sclerotized and much broader antrum, the shorter ductus bursae with a markedly shorter sclerotized section and a smooth surface (it is longitudinally rugose in the continental congeners), and the much smaller, longitudinally elliptical signum bursae (it is transversely elliptical in the mainland M. nigripunctata, M. politzari and M. cryptica). The distinctive characters between M. distinctaria and M. hero, M. herbuloti and M. pluto (Viette, 1971) are discussed under the diagnoses of the latter three species.
Re-description. Adult (Figs 13–14). Forewing length 17.0–18.0 mm. Sexual dimorphism negligible. Antenna ciliate-fasciculate in male, sparsely ciliate, filiform in female. Head relatively small, palp short, porrect, apically pointed, lateral side pale grey, inner side white. Compound eye large, frons broad, quadrangular, whitish-grey with two dark grey hair tufts laterally, vertex off white. Collar pale grey, tegula off white, thorax pale grey, first abdominal segment black, further segments pale grey with sparse brownish suffusion dorsally, off white ventrally. Upperside of wings. Ground colour pale brownish-grey, wing pattern dark grey. Forewing. Basal and subbasal lines deleted; antemedial line fine, but sharply defined, ventral two-thirds slightly undulate, oblique outwards, costal third with sharp inner angle towards costa. Discal spot blurred, relatively large, dash-like, oblique. Medial line diffuse, narrow, costal quarter sharply angled inwards, ventral three-quarters almost straight, slightly zigzagged. Postmedial line thick, sharply defined, ventral two-thirds oblique outwards, slightly sinuous, costal third sharply angled towards costa, straight. Subterminal line diffuse, shadow like, strongly undulate. Terminal line very thin, poorly visible with a row of small black dots at veins in the apical half. Cilia short, pale whitish grey. Hindwing. Antemedial line diffuse, almost straight. Discal spot well developed, blurred, oval. Medial line thin, slightly undulate and gently arched in upper two-thirds, thickened, abruptly forming a short, concave arch near anal margin. Postmedial line broad, diffuse, gently undulate in costal half, almost straight, gradually thickened in anal half. Subterminal line diffuse, interrupted, poorly visible. Terminal line fine, sinuous; cilia as on forewing. Underside of wings. Ground colour pale brownish-grey; discal spots large, sharply defined, black, elliptical, forewing discal spot twice as large as that of hindwing; traces of transverse lines absent. Subapical area of fore- and hindwing with a large, rounded-quadrangular, somewhat diffuse, dark grey blotch, forewing subapical blotch somewhat larger than that of hindwing; terminal area of fore- and hindwing slightly darkened.
Male genitalia (Fig. 32). Uncus medium long, elongate digitiform, narrow at base, apically rounded, densely covered in fine, long setae. Gnathos very short and narrow, weakly sclerotized, without dilated medial plate. Tegumen short and broad. Juxta shield-like, heavily sclerotized anteriorly and laterally, forming horseshoe-shaped basal margin. Vinculum very short and broad, apically rounded, saccus short, triangular. Valva very broad at base, basal half moderately sclerotized, scobinated, bearing a stout, quadrangular costal arm ending in pointed thorn-like process pointing caudad. Distal half of valva heavily sclerotized, apical third narrow, thumb-shaped; medial section of ventral margin evenly convex ventrally, postmedial section deeply concave, distal section gently convex, apex rounded and covered sparsely in long setae. Sacculus long and narrow, moderately sclerotized, with a short, broadbased conical process pointing ventrad. Aedeagus short and stout, anterior quarter slightly curved ventrad, coecum short, broadly rounded, medial and distal section straight, apex with moderately sclerotized, short, dorsally rounded, ventrally straight carina; vesica with a single, short, thin, pointed, needle-like cornutus with bulbous base.
Female genitalia (Fig. 39). Ovipositor moderately long, papilla analis elongate, apically rounded, sparsely setose, posterior apophysis long and thin, ca. twice as long as anterior one. Eighth tergite shield-like, distal margin gently arcuate, proximal margin undulate with a shallow medial depression. Ostium bursae broad, round, heavily sclerotized, antrum short, heavily sclerotized, caliciform. Ductus bursae short, relatively thick, distal two-thirds heavily sclerotized without striation, proximal third membranous, gradually dilated anteriorly. Cervix bursae very small, membranous, erected at proximal end of ductus bursae. Corpus bursae elongate ovoid, signum bursae longitudinally elliptical, with short, strongly sclerotized crest anteriorly and laterally, reminiscent of a horseshoe encompassing a finely scobinated oval internal plate.
Genetic information. The authors of this paper could not access specimens suitable for DNA sequencing.
Distribution (Fig. 43). Morabia distinctaria is endemic to Mauritius.
description: Published as part of László, Gyula M. & Hausmann, Axel, 2022, Taxonomic review of the genus Morabia Hausmann & Tujuba, 2020 with descriptions of two new species and introducing five new generic combinations (Lepidoptera, Geometridae, Ennominae), pp. 215-237 in Zootaxa 5134 (2) on pages 229-230, DOI: 10.11646/zootaxa.5134.2.3, http://zenodo.org/record/6534856