Introduction

Eriocera Macquart, 1838 is a subgenus of the genus Hexatoma Latreille, 1809 in the family Limoniidae. It is distributed worldwide, with 567 known species and subspecies, of which 75 taxa are from the Palaearctic Realm, 34 taxa from the Nearctic Realm, 143 taxa from the Neotropical Realm, 30 taxa from the Afrotropical Realm, 290 taxa from the Oriental region, and five taxa from the Australasian/Oceania realms (Oosterbroek 2026). Thus, the subgenus is large and morphologically diverse, and it was confirmed to be non-monophyletic by Ribeiro (2008). It is characterised by the following characters: body medium-sized to large; antenna with 4–10 flagellomeres; wings often unpatterned through variously darkened, or with a conspicuous hyaline and yellow cross banded pattern, or abundantly spotted and dotted with brown; cell dm present; three or four branches of M reaching margin; clasper of gonostylus narrowed apically into a long, curved spine; lobe of gonostylus short, stout, and with setae; gonocoxite moderately stubby or elongate-cylindrical; interbase usually cylindrical, or triangular with a sharp spine at base, or with a two-layered membranous structure with spine at apex; aedeagus usually short and relatively inconspicuous or directed ventrally (Alexander and Lloyd 1914; Edwards 1921; Alexander 1948; Joseph 1977; Alexander and Byers 1981; Savchenko 1986; Podenas et al. 2006; Ribeiro 2008; Podeniene and Gelhaus 2015; Zhang et al. 2021; Podenas et al. 2022).

The species group H. (E.) plumbicincta (Brunetti, 1911) possesses highly distinctive morphological characters within the subgenus H. (Eriocera). It is characterised by the following characters: head and thorax velvet-black; antenna 7-segmented (Fig. 2A–D); wing mainly dark brown, yellow, yellowish-brown, whitish-hyaline; with a whitish-hyaline, oblique medial stripe; a small whitish hyaline spot in cell R1; apex with a big whitish-hyaline stripearound R4; M1 present, longer than its petiole; m-cu at outer end of cell dm (Figs 1A, 2C, 3D, 5B); male terminalia orangish yellow or reddish brown; ninth tergite short, with posterior margin concave; aedeagus extremely long, overall U-shaped, dorsal side robust, strongly sclerotised; ventral portion slender, rod-shaped, medially with numerous short setae; interbase rod-shaped, with a triangular process at base; paramere and aedeagal apodeme flattened in lateral view (Figs 1A, 2E, 4, 7) (Brunetti 1911; Edwards 1921; Alexander 1942; Joseph 1977; Men and Yu 2015). To date, only two species of the plumbicincta species group have been known to occur in China (Oosterbroek 2026): H. (E.) chrysomela (Edwards, 1921) from Fujian, Guangdong, Hong Kong and Jiangxi Province and H. (E.) sincera Alexander, 1942 from Yunnan Province. Currently, H. (E.) chrysomela is reported for the first time from Guangxi, Guizhou, and Hunan Province, one new species H. (E.) guangxiensis sp. nov. is described and illustrated from Guangxi and Yunnan Province. A key to the species group H. (E.) plumbicincta from China is provided.