Alcis linzhiensis Pan & Yu, 2025

Yu, Xia, Jiang, Xinrui, Wang, Han, Pan, Zhaohui & Han, Hongxiang, 2025, The genus Alcis Curtis, 1826 from Xizang, China, including a new species (Lepidoptera: Geometridae: Ennominae), Zootaxa 5711 (3), pp. 444-450 : 445-446

Alcis linzhiensis Pan & Yu sp. nov.

( Figs 1–4 , 13–14, 21–22, 29)

Type material. Holotype ♂ ( XAAHU), CHINA: Xizang, Zayü, Cibagou , 1645 m, 3–9.vii.2016, slide no. 5027, leg. Pan Zhaohui. Paratypes, CHINA: Xizang , 1♀ ( XAAHU), Nyingchi, Institute of Plateau Ecology , 2912 m, 12.x.2014, slide no. 4669, leg. Pan Zhaohui ; 1♂ ( XAAHU), Nyingchi , 106k, 2160 m, 2.x.2018, slide no. 4575, leg. Zhou Runfa ; 2♂ ( XAAHU), Nyingchi, East slope of Mount Sejila , 2060 m, 7.ix.2020, 5.x.2020, leg. Pan Zhaohui ; 2♂ ( XAAHU), Nyingchi, Mêdog 80k, 2118 m, 25.vii.2015, 8.vi.2017, leg. Pan Zhaohui ; 1♂, 1♀ ( IZCAS), Cona, Lexiang, Senmuzha , 2741 m, 2.vi.2016, leg. Li Xinxin , slide no. Geom-7332 ( ♂), 7333 ( ♀).

Diagnosis. On the wing pattern, the new species is almost identical to A. arisema Prout, 1934 ( Figs 5–6 ), and it only can be distinguished by the forewing antemedial line being further from the postmedial line on the inner margin. In the male genitalia, there are some clear diagnostic characters: in the new species the cucullus is elongate, extending beyond the valva, not swollen at tip, and the ampulla is large and tongue-like. In A. arisema , the cucullus is instead swollen into a semicircular process, not extending beyond the valva, and the ampulla is very small (Figs 15, 23).

Description. Antennae with basal 2/3 bipectinate in male, longest ramus about four times diameter of antennal shaft; filiform in female. Head brown. Frons brown. Labial palpus with third section elongated, extending beyond frons. Thorax brown. Male hind tibia with two pairs of spurs. Length of forewing: 19–21 mm in male ( 20 mm in holotype) and 20 mm in female. Forewing ground color white; area between wing base to antemedial line brown; antemedial line waved, concave in both sides of lower margin of cell and forming a small angle on it, convex around vein 2A; medial line obsolete, a small black rectangular patch present at middle of costa; postmedial line welldeveloped, widely M-shaped, with anterior part vertical to costa, then strongly convex between vein M 1 and M 3, and between vein CuA 1 and vein 2A, posterior part slant to inner margin; submarginal areas brown; fringes chequerred with black and brown. Hind wing ground color white; postmedial line black, extended from dorsum to vein M 1; submarginal area suffused with black scales; marginal line black; fringes checkered with grey and blackish brown. Discal spot black short strip on both wings. Underside paler than upperside; black spots present on veins proximal to postmedial line and on veins anterior to vein M 1. Abdomen black, covered by white scales dorsally and yellow scales laterally.

Male genitalia (Figs 13–14, 21–22). Uncus broad at base and gradually narrow towards blunt tip. Tegumen short and broad. Gnathos simple, without median process. Juxta shield-like, bilobated distally and forming a pair of long processes. Saccus short. Valva moderately broad; costa swollen at basal half; cucullus narrow and elongate, extending downwards to basal one third of costa; ampulla almost a tongue-like spinose sclerite.Aedeagus moderately long, with a long rod like lateral process; vesica totally covered by spinules.

Female genitalia (Fig. 29). Papillae anales broad and stout; apophyses posteriores about twice length of apophyses anteriores. Ostium bursae rounded. Lamella postvaginalis one pair of large subsquare sclerotized sclerites. Ductus bursae very short. Colliculum distinct. Corpus bursae long and narrow, sclerotized laterally and posteriorly, signa two spinules patches.

Distribution. China ( Xizang).

Etymology. The specific epithet is from the locality where the paratypes were collected.

Figures

FIGURES 1–12. 1–4, A. linzhiensis sp. nov.: 1. holotype, male, upperside; 2, ibidem, underside; 3, paratype, male; 4, paratype, female. 5–6, A. arisema: 5, male, upperside; 6, ibidem, underside; 7, A. decussata, male; 8, A. limbui, male; 9, A. sinadmissa, male; 10, A. extinctaria, male; 11–12, A. maculata: 11, male; 12, female. Scale bar = 1 cm.