Xenortholitha falcata Yazaki, 1993

Mallick, Kaushik, Bandyopadhyay, Uttaran, Mazumder, Arna, Dey, Rushati, Raha, Angshuman, Sanyal, Abesh Kumar, Gupta, Sandeep Kumar, Uniyal, Virendra Prasad & Chandra, Kailash, 2021, First Record of Xenortholitha falcata Yazaki, 1993 (Geometridae: Larentiinae) from India, Records of the Zoological Survey of India 121 (4), pp. 483-486 : 484-486

Xenortholitha falcata Yazaki, 1993 ( Figure 2A–2D )

1993. Xenortholitha falcata Yazaki , Tinea , 13 (3): 110, pl. 59, fig.33, Holotype ♂, Nepal: Godavari.

Material examined: 1 ♂: India, Himachal Pradesh, Dist. Kullu, Great Himalayan National Park, Ropa FRH ,

31.7655°N, 77.3576°E, 1515 m ASL, 03-iv-2018; 1 ♂: 23- iv-2018; 1 ♂: 19-ix-2019; 1 ♂: 23-ix-2019; 1 ♂: Padhar,

31.7499°N, 77.3732°E, 2437 m ASL, 19-vi-2018, leg. K. Mallick. 1 ♂: Dist. Kangra, Dharamsala, Cant. Road,

32.23165°N, 76.31414°E, 1492 m ASL, 24-x-2018; 1 ♂: 25-x-2018; 1 ♂: 29-x-2018, leg. A. Raha & Team.

1 ♂: India, Uttarakhand, Dist. Uttarkashi, Govind Wildlife Sanctuary, Haltari , 31.0609°N, 78.1272°E, 2000 m ASL, 09-vi-2011 ; 1 ♂: Dist. Pithoragarh, Askot Wildlife Sanctuary, Chilamdhar , 30.13751°N, 80.24781°E, 1714 m ASL, 09-x-2017, leg. A.K. Sanyal & Team.

All the specimens were deposited in Himalayan Lepidoptera collection in Lepidoptera Section, Zoological Survey of India, Kolkata.

Description: Forewing length: 27 mm; Wings elongated with acute apex; forewing dark fuscous-brown; creamy-white sub-basal, antemedial and post-medial irregularly curved lines; the area between ante- and post-medial lines darker than overall ground-colour; a black, elongated discal streak; series of creamy-white submarginal dots, the largest and uppermost one just below costa; a small, dark apical streak; marginal series of paired, blackish

Kaushik Mallick, Uttaran Bandyopadhyay, Arna Mazumder, Rushati Dey et al., spots on each side of vein - endings; Hindwing paler brown with a creamy-white postmedial line, excurved on vein CuA 1 and a blackish, crescent-shaped discal spot. Underside of forewing more purplish-brown with dark suffusion in the medial area; postmedial line crenulated, with strong outward angulation at M 3, below which it is concave up to 1A+2A, on which it has another smaller angulation; series of submarginal dots as in upper side; a minute, black discal dot; underside of hindwing with highly crenulated, black post-medial line and large, black discal dot.

Uncus very long, broad at base, gradually becoming narrow with pointed tip; valvae spindle-shaped, with more or less roundish apex; a very slender, curved, long costal basal process reaching almost the base of uncus; saccus round; juxta moderately sclerotized and bifurcated medially. Aedeagus long, slender, basal part moderately sclerotized; vesica less sclerotized, with a bunch of small cornuti.

Diagnosis: X. falcata superficially resembles X. propinguata epigrypa ( Prout, 1939) ; but the species can be easily distinguished based on the following characters: wing size much larger; forewing apex-strongly falcate, ground-colour of forewing dark fuscous brown instead of pale brown; discal dot larger, darker and more prominent; terminal area of forewing irrorated with grey instead of pale ochreous; Hindwing ground-colour pale fuscous-brown, darker than sister species. This species can be distinguished from X. propinguata propinguata ( Kollar, 1844) by the much darker terminal area and lacking any triangular marking in the forewing apex. Xenortholitha falcata also differs from X. latifusata ( Walker, 1862) by the hindwing discal spot not biangulate as in latifusata .

Xenortholitha falcata can be easily identified by its very long uncus, longer than the closely related sister species.

Distribution: Nepal, India (Himachal Pradesh, Uttarakhand) (New record).

Bionomy: The species was recorded within an altitudinal range of 1500 m to 2500 m, mostly in Himalayan Upper Chir Pine Forest habitat, sometimes also from Temperate Conifer forests. It was active all through the year, with individuals getting recorded in spring (March-April), summer (June) and post-monsoon (October) seasons.

Figures

Figure 2. Habitus and male genitalia of Xenortholitha falcata. A. Upper side of ♂ B. Under side of ♂ C. Ventral view of male genitalia D. Aedeagus.