Miridiba castanea (Waterhouse, 1875) Figs 28–31 Holotrichia castanea Waterhouse, 1875: 104 (type loc.: Kawachi, Japan). Holotrichia castanea – Dalla Torre 1912: 201 (catalogue). — Chang 1964: 149–150, figs 60–61 (combination; species list; in key). Neodontocnema castanea – Arrow 1948: 51 (combination). Miridiba castanea – Isida & Fujioka 1988: 35 (combination; catalogue). — Smetana & Král 2006: 222 (catalogue). — Coca-Abia 2008: 677, 684 (type material; in key). — Kim 2011: 6, 17, 139 (catalogue). — Bezděk 2016: 271 (catalogue). — Gao et al. 2018: 13 (catalogue); 2019: 461 (species list; in key). Diagnosis External morphology of adult (Fig. 28). Length 18.5–22.5 mm. Dorsal surface glabrous. Clypeus as long as frons, flat, with anterior edge emarginate at middle. Frons with inconspicuous short pubescence hardly noticeable and some sparse long setae; frontal carina moderately developed. Pronotum glabrous, at most, with short setae in each puncture hardly visible; anterior margin with short and sparse setae; without concavity at each lateral end; posterior and lateral margins smooth and glabrous; anterior angles obtuse, not projected forward, moderately elevated laterally. Prosternal process rounded in shape, bulging ventrally. Scutellum glabrous and punctate. Elytra glabrous, at most, some sparse setae on basal margin and short setae in each puncture hardly visible; epipleuron with pubescence on full length, sparse on apex. Foretibia with moderately developed dorsal carina; insertion of inner spur in male equidistant between second and third outer tooth, insertion of inner spur in females closer to third outer tooth than second one. Meso- and metatibia with strong punctures; transverse carina interrupted at middle, with a dorsal and ventral prominence; inner margin of dorsal surface with strong spines. Prepygidium regularly punctate, conspicuous short pubescence. Pygidium regularly punctate; conspicuous pubescence on disc, longer toward apex; apical margin widened and gently raised. Ventrites with conspicuous pubescence, more scattered on third and fourth ventrites. Ventrite 5 moderately depressed at posterior half. Ventrite 6 bulging at anterior margin, bulge without punctures. Male genitalia: parameres (Fig. 29) with dorsal branches gently curved, their apices surpassing those of ventral branches; ventral side of dorsal branches and dorsal side of ventral branches with sparse granules, each one with a short seta (Fig. 29C). Endophallus with spines near distal end (Fig. 30) and dense raspula at proximal position. Temones reduced, apophysis separated from each other at distal end. Female genitalia (Fig. 31): genital chamber with a pair of vestigial sternites reduced to a few sensillae. Peduncle of bursa copulatrix reduced. Median oviduct well developed with hardened epithelium. Material examined Lectotype JAPAN • ♂; “S. Japan” [Southern Japan]; “ Holotrichia castanea (Type) C. Waterh.”; “TYPE”; “LECTOTYPE”; “LECTOTYPE Miridiba castanea (Watrerhouse, 1875) M. Coca-Abia, det. 2001”; BMNH. Paralectotype JAPAN • 1 ♂; same collection data as for lectotype; “PARALECTOTYPE”; “PARALECTOTYPE Miridiba castanea (Waterhouse, 1875) M. Coca-Abia, det. 2001”; BMNH. Other material JAPAN • 1 ♂; Japan; 1910; G. Lewis leg.; BMNH • 1 ♀; Mt Simbara; 1901; P.A. Holst leg.; BMNH • 1 ♂; Kyoto; 18 May 1932; Yie S. leg.; IZCAS. CHINA – Beijing • 1 ♀; Mt Shangfangshan; 27 Aug. 1965; Y.-J. Liu leg.; Y.-W. Zhang det.; IZCAS. – Chongqing • 1 ♂; Wulong; 650 m a.s.l.; 5 Jul. 1989; B.-W. Sun leg.; Y.-W. Zhang det.; IZCAS. – Gansu Prov. • 1 ♂; Tianshui, Mt Maijishan; 24 Jul. 1986; C.-Z. Wang leg.; Z.-L. Zhang det.; SYAU. – Liaoning Prov. • 1 ♀; Chaoyang, Beili; 1984; J. Liu leg.; Y.-W. Zhang det.; IZCAS. – Shanxi Prov. • 1 ♂; Mt Zhongtaioshan; 30 Jul. 1995; W.-Z. Li leg.; Y.-W. Zhang det.; IZCAS. – Sichuan Prov. • 1 ♂; Mt Emeishan, Baoguosi; 25 Apr. 1957; Y.-C. Lu leg.; Y.-W. Zhang det.; IZCAS. Remarks Isida & Fujioka (1988) transferred this species to Miridiba. Coca-Abia (2008) studied and designated a lectotype and a paralectotype. This species shows the external morphology and male and female genitalia that characterize morphotype I “ Trichophora ”. Hence, M. castanea is included in this genital morphotype. Distribution China (Beijing, Chongqing, Gansu, Liaoning, Shanxi, Sichuan), Japan: (Honshu island: Osaka, Kyoto), Korean Peninsula, Russian (S Far East).

Published as part of Gao, Chuan-bu & Coca-Abia, María Milagro, 2021, Revision of the genus Miridiba Reitter, 1902 (Coleoptera, Scarabaeidae, Melolonthinae): genital morphotypes and new taxonomic data, pp. 1-94 in European Journal of Taxonomy 749 on pages 21-23, DOI: 10.5852/ejt.2021.749.1355, http://zenodo.org/record/4770293