Stenoloba chuxionga Li & Han, sp. nov.

(Figs 1, 2, 7, 11)

urn:lsid:zoobank.org:act: 4C039B0B-F50B-4CFD-86F7-019CB97041F2

Type material. Holotype. [CHINA] ♂, Chadian Town, Wuding County, Chuxiong Prefecture, Prov. Yunnan, 21 May 2022, H.L. Han, R. T. Xu leg., slide LJ-107-1, coll. NEFU. Paratypes. [CHINA] 1♂, 1♀, same data as for holotype, slide LJ-319-1 and LJ-106-2, coll. NEFU; [CHINA] 1♂, Maojie, Wuding County, Chuxiong Prefecture, Prov. Yunnan, 22 May 2022, H.L. Han, J.J. Fan, R. T. Xu leg., slide LJ-138-1, coll. NEFU.

Diagnosis. The new species belongs to the S. oculata species-group. In contrast to all species in the S. oculata species-group, S. chuxionga sp. nov. is very similar to Stenoloba plumbeoviridis Han & Kononenko, 2018 (Figs 3, 8). In terms of adult features, S. chuxionga sp. nov. has a head and thorax that are yellowish brown (in S. plumbeoviridis plumbeous green); forewing ground color yellowish brown with a more pronounced tan tone (in S. plumbeoviridis plumbeous grey with an intensive greenish tint); basal line field grayish yellow (in S. plumbeoviridis green); antemedial line field yellowish brown (in S. plumbeoviridis plumbeous green); costal margin area yellowish brown with some irregular dark brown stripes (in S. plumbeoviridis green dusting and diffused dark bases of transversal lines); medial line area yellowish brown (in S. plumbeoviridis plumbeous green); reniform spot brownish ovoid patches surrounded by dark brown dots on the lateral side (in S. plumbeoviridis as a patch of black scales, encircled inwardly by a semi-lunar line); postmedial line distinct (in S. plumbeoviridis indistinct); cilia brown (in S. plumbeoviridis plumbeous brown).

For male genitalia, uncus apically blunt (in S. plumbeoviridis sharp); valva almost equal width between base and middle (in S. plumbeoviridis broad at the base); sacculus is almost as wide as costa (in S. plumbeoviridis wider than sacculus); distal costal process protrudes diagonally upwards (in S. plumbeoviridis has a smoother protrusion angle); distinct sacral process is relatively small, protruding inward in a finger shaped, and strongly sclerotized (in S. plumbeoviridis indistinct). There was no obvious diverticulum on the vesica (in S. plumbeoviridis bearing a small triangular diverticulum); vesica with a long cornuti band (in S. plumbeoviridis without cornuti).

Description. Adult (Figs 1, 2). Wingspan 27 mm in male, female 24 mm. Head and thorax yellowish brown, the latter densely covered with some brownish and grayish white scales.Abdomen brown and mixed with grayish white. Forewing ground color yellowish brown with a more pronounced tan tone; costal and inner margins almost parallel; basal line field light grayish yellow; basal band distinct, brownish; subbasal line distinct, double; antemedial line, brownish, double; antemedial line field yellowish brown; costal margin area yellowish brown with some irregular dark brown stripes; medial line area yellowish brown; reniform spot brownish ovoid patches surrounded by dark brown dots on the lateral side; orbicular spot yellowish brown, with some black dots; postmedial line distinct, double, serrate; subterminal line brown, single, wide, divergent and wave shaped; terminal line distinct and composed of discontinuous black brown dots; cilia brownish. Hindwing are overall yellowish brown, mixed with grayish white; the discal spot distinct, terminal area and cilia light yellowish.

Male genitalia (Fig. 7). Uncus short and small, apically blunt, about 1/6 length of tegumen; tegumen wider and spoon shaped; vinculum relatively long, about twice as long as tegumen. Juxta tongue shaped (or nearly diamond shaped). Valva almost equal width between base and middle, beginning to narrow proximally, about 2 times the length of tegumen; cucullus extends outward and has more strong setae distributed on the inner side; sacculus large and strongly sclerotized and extended to the valva 2/3, almost as wide as costa; distinct sacral process is relatively small, protruding inward in a finger like shape, strongly sclerotized; costa strongly sclerotized and extends inward to form a flat finger like protrusion. Aedeagus about as long as vesica, tubular; caecum slightly enlarged; vesica as a whole is vesicular tubular, slightly bulbous at the top, extending laterally below, with a long cornuti band.

Female genitalia (Fig. 11). Papillae anales broadly conical shaped; apophysis anteriores is slightly shorter than apophysis posteriors, and the former is thicker than the latter. Antrum large, strongly sclerotized, funnel shaped. Ductus bursae long, strongly sclerotized, with membranous ring in joining with antrum. Corpus bursae membranous, long funnel shaped, slightly curved inward on both sides, as long as ductus bursae; signa bowling ball shape, with one appendix bursae.

Bionomics. This species is only known from the type locality, where is in the mountainous area with an altitude of about 2000 meters. Three males and one female were collected in May 2022.

Distribution (Fig. 13). Southwest China (Prov. Yunnan).

Etymology. The species name refers to its collection site, Chuxiong Prefecture in Prov. Yunnan.

Remarks. Stenoloba oculata species-group currently includes 11 species: S. albiangulata (Mell, 1943), S. oculata Draudt, 1950, S. oculatoides Han & Kononenko, 2018, S. brunnescens Kononenko & Ronkay, 2000, S. plumbeoviridis Han & Kononenko, 2018, S. plumbeobrunnea Han & Kononenko, 2018, S. cucullata Han & Kononenko, 2018, S. yenminia Ronkay, 2001, S. qingchenga Pekarsky, 2018, S. leonie Pekarsky, 2018, and S. chuxionga Li & Han, sp. nov.

Stenoloba chuxionga sp. nov. shares several important characteristics with other species that are typical of the S. oculata species-group. The structure of the male genitalia reveals that the uncus is usually shorter, apically blunt; both sacculus and costa are hardened to varying degrees and have different shapes, the latter is characterized by a finger shaped or hill shaped protrusion in the middle or proximal part. Valve is relatively wide from the base to the middle, displaying hardened to varying degrees, with narrowing commences at the cucullus, where the outer edge nearly straight; additionally, cucullus usually have a protruding structure of various shapes extending outward, with corona; lastly, juxta usually large and tongue shaped or rhombic.