Berotha incurvata sp. nov.

(Figs 5, 17–23, 30)

Diagnosis. The new species is characterized by the male sternum 8 posteriorly with a median convexity, which is only 1/4 length of sternum 8, the male sternum 9 with paired vertically incurved lateral lobes, each lobe with five little teeth, the male gonocoxite 9 with a slender hook-like apex in lateral view, and the complex of male fused gonocoxites, gonapophyses and gonostyli 10 with distinct bristle-bow, reaching to segment 8 anteriorly.

Description. Male. Body length 7.6 mm; forewing length 11.0 mm, hindwing length 9.0 mm.

Head yellow, with dense brown spots and brown setae. Compound eyes blackish brown. Antennae pale yellow with yellowish setae; scape long, with brownish spots, as long as proximal six flagellomeres.

Thorax pale yellow; pro- and mesonotum yellow, with dense brown spots, meso- and metanotum with paired brown marking. Legs pale yellow with brown setae; femur with a large rounded blackish marking near base, tibia and tarsus with dense blackish brown spots. Forewing with falcate apex, slightly smoky brown, darker along distal margins, with brown spots on branching points of longitudinal veins and some connection points of branches and posterior margin, gradate series with dark brown markings; pterostigma narrowly elongate, reddish brown, with hyaline parts at middle. Longitudinal veins pale yellow, interrupted by many brownish spots; crossveins brown. Hindwing slightly paler than forewing, longitudinal veins yellow, crossveins brown.

Abdomen yellowish brown, pregenital segments brown dorsomedially, each pregenital segment darker on anterior margin.

Male genitalia. Sternum 8 posteriorly with a median convexity, which is only a quarter in length of sternum 8 (Figs 17, 19–21). Tergum 9 + ectoprocts in lateral view nearly shell-like (Figs 17, 20). Trichobothria reduced. Sternum 9 largely paired, with strongly incurved lateral lobes, connected by an apodeme, which is present as a subdistally bifurcated bar, apex of each lateral lobe with five teeth (or interpreted as stout setae) (Figs 17–21). Gonocoxites 9 paired, with a slender hook-like apex in lateral view (Figs 17, 20). Complex of fused gonocoxites, gonapophyses and gonostyli 10 forming a basal sclerite which is composed of a rectangular sclerite with paired narrow lobes directed posterolaterally, and a bow formed by bundled bristles, which extends anteriorly to segment 8 and ends in a bundle of free bristles (Figs 22–23). Fused gonocoxites 11 (= gonarcus) arched, small, band-like, proximally bifurcated (Figs 17–23). Hypandrium internum large, subtriangular (Figs 20–21).

Materials examined. Holotype ³, China, Yunnan, Puer City, Simao District, Dachun River [λėffi], 1750 m, 21.IV.2019, Hongyu Li (CAU). Paratypes: 1³, Laos, Houaphanh, Sam Nuea, Muang Kham, 1190 m, 10.VI.2017, Xingyue Liu (CAU); 1³, China, Yunnan, Yuxi City, Yuanjiang County, Mt. Jiangdongmianshan [fflữữṪĦƜ], 900 m, 18.IV.2019, Hongyu Li (CAU).

Distribution. China (Yunnan); Laos (Houaphanh).

Etymology. The specific epithet “ incurvata ” refers to the shape of sternum 9, with a pair of strongly incurved lobes. It is a participium perfecti passivum of incurvare (= to make curved), feminine.

Remarks. The species appears closely related to Berotha chouioi Yang & Liu, 2002, from Hainan Island, and to Berotha spetana U. Aspöck, Liu & H. Aspöck, 2013, from Taiwan in having a similar male sternum 8 with a posterior median convexity, and a similar largely paired male sternum 9 with teeth on each lateral lobe. It can be distinguished from the latter two species by the posteromedian convexity of male sternum 8 only 1/4 length of sternum 8 in lateral view and the male sternum 9 with a pair of strongly incurved lobes, the transverse bar connecting lobes of sternum 9 bifurcated at both subdistal ends. In B. spetana and B. chouioi, the posteromedian processus of sternum 8 is respectively 1/2 and 1/3 length of sternum 8, and the male sternum 9 is almost straight, elongated posteriorly, with the connected bar not branched.