Miridiba sus (Moser, 1912) Figs 55–56 Holotrichia sus Moser, 1912: 443 (type loc.: Kuang-tri, Vietnam). Hippotrichia hainana Arrow, 1948: 51 (type loc.: Hainan, China). Holotrichia sus — Chang 1964: 146, 149–150, fig. 56 (species list; in key). — Frey 1970: 250 (in key). Miridiba sus – Itoh 1995: 199, figs 7, 25 (combination). — Coca-Abia 2008: 682–683 (type material; in key). — Bezděk 2016: 272 (catalogue). — Gao et al. 2018: 16 (catalogue); 2019: 461 (species list; in key). Hippotrichia hainana Arrow, 1948: 51. — Chang 1964: 145 (as synonym of H. sus). — Nomura 1977: 88. — Itoh 1995: 199. — Smetana & Král 2006: 222 (catalogue). — Bezděk 2016: 271 (catalogue). Diagnosis External morphology of adult (Coca-Abia 2008). Head and elytra glabrous. Clypeus with anterior edge almost straight. Frontal carina strongly developed. Pronotal surface glabrous, except a tuft of brushshaped pubescence placed longitudinally on the middle line; anterior margin widely flanged with a concavity at each lateral end and pubescent; lateral margins smooth; anterior angles sharp and elevated laterally. Scutellum with lateral margins without punctures. Elytral surface glabrous, epipleuron with pubescence on basal half. Meso- and metatibia with transverse carina interrupted at middle; inner margin of dorsal surface without spines. Pygidium with scattered punctures, inconspicuous pubescence, conspicuous on apex, apical margin moderately raised. Ventrite 5 depressed at posterior half. Male genitalia with thin dorsal branches convergent at apices in dorsal view; apices of ventral branches sharp and abruptly curved outwards ninety degree. Endophallus with spines of different size at distal end. External morphology (Fig. 55) and parameres (Fig. 56) of H. hainana. Female genitalia not studied. Material examined Lectotype of H. hainana (here designated) CHINA • ♂; Hainan; J. Whitehead leg.; “99. 315”; “ Miridiba hainana (Arrow, 1948) CH. Bu Gao det. 2018”; BMNH. Other material of M. sus LAOS • 1 ♂; Muang sing near Haut-mekong; 18 Apr. 1918; R.V. de Salvaza leg.; BMNH. Remarks Itoh (1995) transferred this species to Miridiba and synonymized it with Hippotrichia hainana Arrow, 1948 without justification. Coca-Abia (2008) studied the types and indicated holotypes for M. sus (MFNB) and H. hainana (BMNH). However, Moser (1912) and Arrow (1948) never indicated how many specimens they studied. Therefore, these holotype indications by Coca-Abia (2008) were incorrect (Art. 73.1 ICZN). Hence, the ‘holotypes’ remain syntypes, and other syntypes may be found. In fact, the first author of this work found a syntype of H. hainana in the BMNH collection, which is designated as lectotype herein. Miridiba sus shows features of the external morphology and male genitalia, which characterize Miridiba and morphotype I “ Trichophora ”. Thus, this species is included in this genital morphotype. Distribution China (Hainan); Laos; Thailand; Vietnam.

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 40-41, DOI: 10.5852/ejt.2021.749.1355, http://zenodo.org/record/4770293