Periacma subaequalis Wang & Xu 2024, sp. nov.
Creators: name: Wang, Shuxia
name: Xu, Zhixin
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Lepidoptera
Autostichidae
Periacma
Periacma subaequalis

description: Periacma subaequalis Wang, sp. nov.
(Figs 18, 32, 44)
Type material. CHINA, Yunnan: Holotype ♂, Menglun, Xishuangbanna, 750 m, 24.X.2010, leg. BB Hu et al., slide No. XZX20520. Paratypes: 1♂, Yeixianggu, Xishuangbanna, 762 m, 17.VI.2014, leg. KJ Teng et al., slide No. XZX20628; 1♂, Yexianggu, Xishuangbanna, 762 m, 9.VII.2015, leg. KJ Teng & X Bai, slide No. XZX20629; 2♂ 1♀, Yeixianggu, Xishuangbanna, 762 m, 20‒22.VII.2019, leg. KJ Teng et al., slide No. XZX20627♂, XZX20625 ♀.
Diagnosis. The new species can be distinguished by the sub-rectangular uncus weakly concave at distal 1/3 laterally, the rectangular ventral plate of the gnathos wider than long, and the distally trilobed aedeagus.
Description. Adult (Fig. 18). Wingspan 9.5 ‒ 12.5 mm.
Head. Vertex and frons whitish yellow. Labial palpus pale yellow, in female second segment ringed with black terminally. Antenna yellow on ventral surface; scape brown and flagellum yellow annulated with brown on dorsal surface.
Thorax. Mesonotum and tegula yellow. Forewing yellow, with scattered dark brown scales; dorsum with a black speckle at base; discal spot black, small, ill-defined; postmedial fascia black, narrow medially; ill-defined narrow streak formed by denser black scales extending from above basal speckle of dorsum through cell to inner margin of postmedial fascia, slightly arched to discal spot medially; fringe yellow except black on extension of postmedial fascia around tornus. Hindwing and fringe deep grey. Legs yellow; fore- and midlegs with black scales on dorsal side, hindleg with blackish grey scales on outer side of tibia.
Male genitalia (Fig. 32). Uncus sub-rectangular, concave at distal 1/4 laterally, with setae mediolaterally; apex obtusely rounded, slightly produced medially. Gnathos with basal arm banded, narrowed anteriorly; ventral plate very short, rectangular, width three times of length, slightly extending outward anterolaterally. Valva with costal part narrowly elongate, subparallel from base to before rounded apex; costa smoothly concave medially, bent inward; dorso-proximal process clubbed, with long setae distally; sacculus slightly longer than half length of costal part of valva, narrowed from wide base to basal 2/3, distal 1/3 digitate, free from valva, dorsal margin with a curved process at distal 1/3, fused with valva, ventral margin folded in basal 2/3, sclerotized. Saccus sub-triangular, apex obtusely rounded. Aedeagus slightly shorter than 4/5 length of costal part of valva, widened from near base to basal 2/5, narrowed to before trilobed apex: one lobe sub-triangular, pointed at apex, second lobe digitate, third lobe bootlike.
Female genitalia (Fig. 44). Papilla anale sub-triangular, setose. Apophysis anterioris about 1/2 length of apophysis posterioris. Eighth sternal plate widely concave at middle on posterior margin, forming two papillary lateral lobes bearing long setae. Antrum weakly sclerotized. Ductus bursae membranous, shorter than corpus bursae. Corpus bursae membranous, elliptical; signum small, ovate, with dense granules.
Distribution. China (Yunnan).
Etymology. The specific epithet is derived from the Latin sub- and aequalis, referring to the almost equally wide costal part of the valva.
description: Published as part of Wang, Shuxia & Xu, Zhixin, 2024, Taxonomy of the genus Periacma Meyrick (Lepidoptera: Autostichidae) from China, with a checklist of the world species, pp. 101-129 in Zootaxa 5399 (2) on pages 118-121, DOI: 10.11646/zootaxa.5399.2.1, http://zenodo.org/record/10493947