Revision of the genus Miridiba Reitter, 1902 (Coleoptera, Scarabaeidae, Melolonthinae): genital morphotypes and new taxonomic data

The genus Miridiba Reitter, 1902, of phytophagous chafers from Asia, is revised based on external morphological and genital (male and female) characters. In this study, a total fifty-eight species of Miridiba were examined, and the genus is redescribed. Male genital characters of Miridiba, especially the morphology of parameres and endophallus, are studied in depth herein. The female genitalia of Miridiba are studied and described in detail for the first time. According to genital characters, nine genital morphotypes, including fifty-four species, are established under the genus Miridiba. Sixty-seven type specimens are studied. Miridiba gressitti (Frey, 1970) comb. nov., Miridiba borneensis (Moser, 1918) comb. nov., Miridiba coxalis (Arrow, 1944) comb. nov., Miridiba rugaticollis (Moser, 1913) comb. nov., Miridiba nigrescens (Moser, 1916) comb. nov., Miridiba scutata (Reitter, 1902) comb. nov., Miridiba ciliatipennis (Moser, 1903) comb. nov. and Miridiba brunneipennis (Moser, 1916) comb. nov. are transferred from Holotrichia. Holotrichia dalatensis Frey, 1970 is transferred to Miridiba as a synonym of Miridiba sinensis (Hope, 1842). Four junior subjective synonyms are proposed: Miridiba pilosella (Moser, 1908) (= Holotrichia formosana Moser, 1909), Miridiba sinensis (= Holotrichia dalatensis Frey, 1970), Miridiba scutata (= Holotrichia scutulata Dalla Torre, 1912 and Miridiba lassallei Keith, 2010). Miridiba frontalis (Fairmaire, 1886) is resurrected as a valid species. A key to 51 of the 58 valid species of Miridiba is presented.


Introduction Terminology
The terminology of the numeration of the abdominal segments and other features of adults' morphology follows Crowson (1955Crowson ( , 1981. The ventrites (visible sternites) are numbered from the first, which corresponds to the third abdominal segment until the sixth ventrite (eighth abdominal segment). On the other hand, the terminology employed to describe the male genitalia in this study is that specified by D 'Hotman & Scholtz (1990a). According to these authors, there is some confusion about the orientation of the aedeagus. The tegmen is positioned laterally on one of its sides when at rest and requires rotation for copulation. Taking into account that in copula the male is fixed on the femaleʼs dorsal surface, the concave side of tegmen must be in ventral position in order for copulation to occur. Thereby, for this study, we consider the concave aspect of the tegmen to be ventral and the convex aspect dorsal, as in other Melolonthinae Leach, 1819 (Coca-Abia & Martín-Piera 1998). On the other hand, to specify the position of structures into the endophallus, we consider it at rest (invaginated). The term proximal refers to the cephalic end (anterior). On the contrary, the term distal refers to the caudal end (posterior). The  1-94 (2021) apical ostium of parameres and the vaginal ostium of the genital chamber are in the most caudal end of genitalia (in distal position). Therefore, all internal genital structures placed further from the ostium of parameres or vaginal ostium are at the proximal end. While the genital structures set nearer from the ostium of parameres or vaginal ostium are at the distal end.

Abbreviations
Structures of female genitalia af = anal fold ag = accessory glands bc = bursa copulatrix ep = elongate plates of the median oviduct g = gonopore gf = gonopore fold mo = median oviduct ov = oviduct p = plate (sensorial) pbc = peduncle of bursa copulatrix pg = pygidium r = rectum sp = spermatheca spg = spermatheca gland v = vulva vs = vestigial sternites vt = vestigial tergites Structures of male genitalia cll = collum db = dorsal branch dbs = dorsal branched structure ed = endophallus ma = membranous area nt = notch pb = phallobase rs = area of raspulae sc = scar spn = spines ssa = soft setal area tm = temones vb = ventral branch First ventrite under metacoxa, just its thickened posterior edge visible and not at the same level as next ventrite, with strong and short pubescence. Second ventrite densely punctate, with conspicuous and decumbent pubescence. Third and fourth ventrites with punctures and pubescence irregularly distributed, sparsely at middle and denser at sides. Fifth ventrite more or less depressed at posterior half, densely punctate and with conspicuous pubescence of different lengths. Sixth ventrite more or less concave, densely punctate and with conspicuous pubescence. Parameres with branches of variable shape. Genital chamber with reduced sternites or without them, median oviduct with wrinkled and/or hardened epithelium.

Redescription
External morphology of Miridiba is distinguished by the follow ing combination of features.
pronotum. Widest at posterior half; pronotal surface more or less densely punctate; anterior margin widely flanged, narrowing towards lateral sides; posterior margin not flanged at least at middle; lateral margins smooth (not serrated) or serrated to a greater or lesser extent; anterior angles obtuse or acute, more or less projected; posterior angles obtuse. Prosternal process varying in shapes.
sCutellum. With punctures more or less densely distributed, glabrous.
elytra. Elytral surface without strong striations, at most with weak ones; sutural costa a little more developed than the other ones; punctures less defined than those of pronotum; epipleuron with or without marginal pubescence.
legs. Dorsal surface of foretibia with longitudinal carina developed to a greater or lesser extent and with a longitudinal row of pubescent punctures; three outer strong teeth spaced equally; insertion of inner spur between second and third outer tooth. Meso-and metatibia with transverse carina on outer surface complete or interrupted at middle; dorsal surface with or without spines. Metatibial plates with two articulated free spurs, proximal one behind tarsomere 1 and longer than distal one; the distal spur below tarsomere 1. Fore-and mesotarsi with a tuft of setae on apex underside of tarsomeres 1-4. Metafemora thick, surface with a row of coarse punctures near posterior margin with long and thick pubescence. Hind coxal plate rectangular shaped, with external free vertex forming a right angle. Tarsal claws sickleshaped with one tooth developed at medial.
abdomen. Pygidium with surface punctate and pubescent or glabrous. Ventrite 1 almost completely under metacoxa, just its thickened posterior edge visible, not at the same level as next ventrite, with short pubescence more or less dense. Ventrite 2 densely punctate and with conspicuous, short and decumbent pubescence. Ventrites 3 and 4 with punctures and pubescence irregularly distributed, punctures denser and deeper at sides together with short and sparse pubescence. Ventrite 5 moderately depressed at posterior half, densely punctate and with conspicuous pubescence in different lengths. Ventrite 6 (anal plate) moderately concave, densely punctate with conspicuous pubescence, articulating by a complete suture. Ventrites 2-4 with the suture almost obliterated at middle. male genitalia. Consisting of five parts: 1) Genital segment, derived from abdominal segment 9, resting on ventral wall of abdominal segments 7 and 8 (Krell 1996), consisting of a Y-shaped sclerite (spiculum gastrale), a vestigial sternite and a vestigial tergite, which acting as an anchor for aedeagus to abdominal wall through a connective membrane. 2) Tegmen derived from abdominal segment 10 (Krell 1996) consisting of parameres and phallobase (basal piece), both pieces articulated to each other. Parameres distinctively varying in shapes of dorsal and ventral branches among Miridiba species, apices of branches delimitating apical ostium (caudal); phallobase, a ventrally open structure partly obliterated by connective membrane, without sclerotized plates and with a gently dorsal strangulation as attachment point for connective membrane (Krell 1996). 3) Endophallus (internal sac of aedeagus) lying within tegmen anchored through connective membrane and temones, evaginated during copulation through apical ostium. Epithelium covered with soft sensillae, occasionally, with areas termed raspulae, with dense sensillae and with spines of different sizes and shapes probably acting as a mechanism to anchor endophallus inside female genital chamber during copulation (D'Hotman & Scholtz 1990b). 4) Temones, two dorsal elongate apophysis extending into basal piece; distal ends surrounding endophallus partially or completely. 5) Vesicula seminalis or caudal diverticulum, serving as a sperm reservoir.
Female genitalia. Tubular type (Lindroth & Palmén 1970), usually membranous, with parts of structures sclerotized, consisting of five parts: 1) Genital chamber at posterior extension of oviduct behind sternum 8, symmetrical bilaterally, opens through vaginal ostium or vulva (Snodgrass 1935); dorsal wall with two folds (anal and gonopore folds), allowing its extension and retraction (Fig. 1); anal fold at posterior position with two pairs of vestigial tergites, one pair at each side of rectum; gonopore fold at anterior position above opening of median oviduct (gonopore) and below of anal fold (Fig. 1); ventral wall of gonopore fold with sensory structures (genital palps or styli) or plates located behind gonopore (Fig. 1); ventral anterior end of genital chamber without or with one pair of vestigial sternites European Journal of Taxonomy 749: 1-94 (2021) weakly developed, sometimes with sensory setae. 2) Accessory glands, on each side of anterior end of genital chamber with a dark area; probably produce pheromone for sexual attraction (Zamotailov 1988). 3) Oviducts lead gonads from ovaries and opens ventrally to median oviduct, which is a wide chamber with wrinkled and/or hardened epithelium sclerotized to a greater or lesser extent, median oviduct is opened to genital chamber through gonopore ( Fig. 1) locating beneath genital chamber when the female genitalia rest. 4) Bursa copulatrix, diverticulum with function of storage and enzymatic digestion of spermatophore to deliver sperm (Krell 1996), pedunculated, opens dorsally to median oviduct, with a pouch at proximal position with plicate epithelium and small setae of pressosensorial function (Sanmartín & Martín-Piera 2003), some species with sclerotized structures in peduncle. 5) Spermatheca (receptaculum seminis or seminal receptacle) with function of sperm storage after releasing from bursa copulatrix, pedunculated with a pouch at proximal position, opens to median oviduct ventrally. Spermathecal gland, longer than spermatheca, opens at spermathecal tract just below pouch, its secretion leads sperm chemotactically through a concentration gradient from spermatophore to spermatheca (Krell 1996). Both spermathecal and its gland have a distal tubular duct and a proximal caecum more or less globular.

Distribution
Species of Miridiba are documented in the eastern Palaearctic Region (China, Japan, Korean Peninsula, Far East of Russia) and Oriental Region (India, Indonesia, Laos, Malaysia, Myanmar, Nepal, Thailand, Vietnam).

Genital morphotypes
Based on the examination of type series of twenty-eight species and eight synonymous taxa of Miridiba, nine genital morphotypes were established and described as follows.

Male genitalia
Parameres ( Fig. 2) consisting of two dorsal and two ventral thin branches separated in dorsal, ventral and lateral views; dorsal branches longer than ventral ones; branches start from a collar-shaped structure, termed collum at proximal part of parameres close to phallobase; collum short, with a suture dorsally and ventrally sclerotized to a greater or lesser extent. Endophallus (Fig. 3) slim and graceful with spines becoming larger towards distal end and in some species arranged helicoidally around internal walls of the sac, some species with large spines or raspulae in distal end. Temones (Fig. 3) laid at proximal half of endophallus; gently developed, seldom strongly developed, apophysis fused at proximal end.
Female genitalia (Fig. 4) Anal fold with one tergite of each pair distinctly reduced; gonopore fold with a pair of sensory plates in oval-transverse shaped, plates with sensilla at posterior margin; vestigial sternites absent or weakly developed with a few sensillae. Median oviduct with wrinkled and/or hardened epithelium sclerotized to a greater or lesser extent. Bursa copulatrix with striated pouch. Spermatheca with short peduncle.  (Hope, 1831), lectotype (BMNH), in dorsal (A) and ventral (B) views. Scale bars = 1.0 mm.
simple and similar to those of morphotype I. Endophallus slim and raspulae conspicuous or gently at distal end, spines absent (Fig. 6). Temones laid at proximal half of endophallus, thin and apophysis separated each other (Fig. 6).
Female genitalia (Fig. 7) Anal fold with all vestigial tergites similar in size; gonopore fold with a pair of elongate plates with sensillae at posterior edge; vestigial sternites weakly developed with a few sensillae. Median oviduct with wrinkled and hardened epithelium and two rectangular plates at distal dorsal wall. Pouch of bursa copulatrix striated with punctate sensillae. Spermatheca with short peduncle.
Morphotype III "Leucophthalma" Fig. 8 Male genitalia (Fig. 8) Parameres (Coca-Abia 2008: fig. 17) consisting of dorsal and ventral branches separated in ventral and lateral views; dorsal branches only separated in distal end. Two ventral branches longer than dorsal ones, strong and curved downward. Collum absent. Endophallus with an area of soft setae, hair-like, at distal end, in some species spines arranged helicoidally around internal walls of sac. Temones laid at proximal half of endophallus, reduced; apophysis fused at proximal end.

Female genitalia
Anal fold with all vestigial tergites similar in size; gonopore fold with plates varying in shapes with sensillae at posterior margin; vestigial sternites weakly developed with or without sensillae. Median oviduct strongly sclerotized. Peduncle of bursa copulatrix very long. Spermathecal reduced, gland strongly developed with caecum longer than tubular duct.

Male genitalia
Parameres ( Fig. 9) consisting of one dorsal and two ventral branches separated in lateral and ventral views. Presumably, dorsal branch resulted of two branches coalescence, showing a central sutural scar toward apical ostium varying in shapes and designs at distal end. Ventral branches bilaterally symmetrical, outer edge curved and elevated or straight; inner edge straight and converge at distal end. Collum absent. Endophallus ( Fig. 10) with a few spines and, in some species, raspulae with dense sensillae. Temones laid at proximal half of endophallus, apophysis joined at proximal end, some species with distal ends surrounding endophallus partially (T-shaped) (Fig. 10).
Female genitalia (Fig. 11) Anal fold with all vestigial tergites similar in size; gonopore fold with a pair of plates, without sensillae, in rectangular-elongate shape extending into median oviduct dorsal wall; vestigial sternites weakly developed with a few sensillae. Median oviduct with wrinkled and/or hardened epithelium sclerotized to a greater or lesser extent. Bursa copulatrix with long peduncle. Spermatheca with short peduncle, gland with marked pouch.  , ?syntype (MFNB) in dorsal (A) and ventral (B) views. Scale bars = 1.0 mm.

Male genitalia
Parameres (Fig. 12) consisting of two dorsal and two ventral branches separated in dorsal and ventral views and fused laterally. Lateral scars, presumably, formed by the fusion of dorsal and ventral branches, or joined totally or partially by a lateral membranous area. Dorsal branches with symmetrical or asymmetrical design; collum undefined in lateral view, with a membranous area in dorsal view. Ventral branches bilaterally symmetrical, straight and convergent at distal end. Phallobase shorter than paramere. Endophallus (Fig. 13) with a dense area of small spines (raspulae), stronger towards distal end, or raspulae absent, only acicular soft setae. Temones laid at proximal half of endophallus, slender, apophysis separated each other (Fig. 13).
Female genitalia (Fig. 14) Anal fold with all vestigial tergites similar in size; gonopore fold with a pair of short sensory elongate plates, with sensilla at posterior edge; vestigial sternites weakly developed without apparent sensillae. Median oviduct with wrinkled and hardened epithelium sclerotized to a greater or lesser extent. Bursa copulatrix with short peduncle, pouch arranged transversely. Spermatheca with short peduncle, gland very long.

Female genitalia
Unknown.

Male genitalia
Parameres (Fig. 20) consisting of one dorsal branch semi-tubular with proximal half obturated ventrally by a strong membrane; sutural scar absent; apex varying in shapes. Collum absent. Ventral branches thin, fused to dorsal one, emerging from edge of ventral obturating membrane toward distal end. Endophallus ( Fig. 21) with an area of conspicuous acicular setae (raspulae) and spines at distal end; a few spines isolated at middle of sac. Temones (Fig. 21) laid at distal part of endophallus, slender; apophysis separated.
Female genitalia (Fig. 22) Anal fold with all vestigial tergites similar in size; gonopore fold with a pair of sensory plates in ovaltransverse shaped, plates with sensilla along internal margin; vestigial sternites weakly developed with a few sensillae. Median oviduct slightly developed with membranous epithelium. Bursa copulatrix with part of peduncle striated. Spermatheca with long peduncle.

Male genitalia
Parameres (Fig. 23) consisting of one strong dorsal tubular complex divided into two parts, both parts with two branches at distal end; upper part with branches ( Fig. 23A) varying in shapes and length; branches of lower part (Fig. 23B) shorter than those of dorsal part, convergent at distal end with varying shapes tips. In lateral view, branches of dorsal complex form a concavity (Fig. 23C) varying in shapes. Collum absent. Ventral branches reduced, fused laterally to dorsal tubular complex with a weak lateral scar. Endophallus with short spines and pointed sensilla at middle (Gao et al. 2018: fig. 3j). Temones slender and apophysis separated (Gao et al. 2018: fig. 3j).

Female genitalia
Not studied.

Species included in Morphotype I "Trichophora"
The group is composed of twenty-nine species, which are characterized by antenna 9-segmented, head and pronotal surface densely punctate (distance between punctures smaller than diameter of puncture) and male and female genitalia as specified above.

Remarks
Coca-Abia (2008) designated the lectotype based on a specimen preserved in the Hungarian Natural History Museum (Budapest). An additional syntype has been found in the Léon Fairmaire collection (MNHN) with an identification label handwritten, specifying Tchang-Yang as locality. This locality was cited by Fairmaire in the original description, which makes it the typical locality. According to the ICZN (Art. 72.4.1.1) "For a nominal species or subspecies established before 2000, any evidence, published or unpublished, may be taken into account to determine what specimens constitute the type series" (sic). Two pieces of evidence support our decision to consider this specimen belonging to the type series: it is preserved in the collection of L. Fairmaire and has a handwritten label specifying Tchang-Yang as locality. Thus, this syntype specimen is indicated herein as paralectotype.

Remarks
Although the type specimens of M. abdominalis was never studied, this species was transferred to Miridiba (Nomura 1977) and currently belongs to this genus (Coca-Abia 2008; Bezděk 2016). The lectotype is designated herein based on a syntype deposited in the Natural History Museum, London (BMNH). Hope (1831) did not indicate how many specimens he studied, and in case other syntypes are found, the known syntype is herewith designated as the lectotype. According to the features of the female genitalia, we consider that this species belongs to genital morphotype I "Trichophora".  Fig. 27

Diagnosis
External morphology of adult (Fig. 27

Remarks
This species was transferred to Miridiba, and a type specimen (MFNB) was indicated as holotype (Coca-Abia 2008). Moser (1913a) did not indicate how many specimens he studied, so the indication as holotype by Coca-Abia (2008) was not valid (Art. 73.1 ICZN) (the specimen labelled as holotype was lost on the way back to MFNB). One syntype has been found in Natural History Museum of London (BMNH), which is designated as lectotype herein. The external morphology and male genitalia indicate that this species belongs to morphotype I "Trichophora".

Diagnosis
See Sabatinelli (1983). Sabatinelli (1983) described Neodontocnema brancuccii ignoring the papers of Chang (1964) and Nomura (1977) in which Neodontocnema was synonymized with Miridiba. Later, Smetana & Král (2006) transferred this species to Miridiba, which was confirmed by Bezděk (2016). According to the original description based on a unique male specimen, features of male genitalia such as parameres with two dorsal and two ventral branches (Sabatinelli 1983: figs 1-2) characterize to morphotype I "Trichophora". Hence, this species is included in this genital morphotype.

Diagnosis
External morphology of adult (Fig. 28).  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.  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.

Diagnosis (from Coca-Abia 2008)
Head glabrous, except for vertex with thin pubescence, clypeus with anterior margin moderately emarginate at middle. Pronotum glabrous on disc, at most, with short setae in each puncture hardly visible; anterior margin elevated with a perpendicular anterior face, without a concavity at each lateral end and with short pubescence; anterior angles blunt and not projected. Epipleuron with pubescence except on apex. Foretibia with gently developed dorsal carina. Meso-and metatibiae with spines on dorsal surface; transverse carina interrupted and complete, respectively, placed behind middle. Pygidium with scattered punctures and sparse pubescence, conspicuous on apex. Male genitalia: dorsal branches of paramere ventrally with granules each one bearing a short seta. Apices of ventral branches S-shaped in lateral view, with granules and setae at dorsal and ventral sides.

Remarks
Coca-Abia (2008) studied Miridiba coromandeliana and designated a lectotype and a paralectotype. Features of morphotype I "Trichophora" are present in M. coromandeliana. Hence, this species is included in this genital morphotype. On the other hand, Holotrichia conferta Sharp 1903 was synonymized with N. coromandeliana, type species of Neodontocnema (Arrow 1948). Frey (1971) and Sabatinelli (1983) deemed that both taxa were valid species by considering them separately in identification keys of Neodontocnema, while without giving any further justification. In the original description of H. conferta, Sharp (1903) mentioned an old specimen in the British Museum labelled "Madras" and several other specimens in the Cambridge Museum, British Museum and D. Sharp collections. Two male specimens of the Sharp collection have been found in BMNH, which are labelled as the type and cotype. Both specimens of H. conferta show features of external morphology and male genitalia that characterize M. coromandeliana (Coca-Abia 2008: fig. 10). Then, we confirm the synonymy of H. conferta with M. coromandeliana (Arrow 1948), and designate them as lectotype and paralectotype of Miridiba conferta.

Diagnosis
External morphology of adult (Coca-Abia 2008). Dorsal surface glabrous. Clypeus with anterior edge rather emarginate at middle but not deeply. Frons with strong carina. Pronotum with anterior margin with a concavity at each lateral end, glabrous; anterior angles projecting with blunt apices. Epipleuron partially pubescent. Meso-and metatibiae with transverse carina interrupted at middle and inner margin of dorsal surface with spines. Pygidium with pubescence and conspicuous punctures, apical margin moderately widened and raised.

Remarks
Coca-Abia (2008) studied this species and designated a lectotype and three paralectotypes. Miridiba diversiceps shows features of external morphology and genitalia that characterize morphotype I "Trichophora". Hence, this species is included in this genital morphotype.

Diagnosis
External morphology of adult (Fig. 32

Remarks
Coca-Abia (2008) studied and designated a lectotype and three paralectotypes. Moreover, the first author of this paper found another former syntype (BMNH) indicated as a paralectotype herein. Antenna 9-segmented, and parameres with two dorsal and two ventral branches separated from each other (Coca-Abia 2008: figs 12-13), which characterize morphotype I "Trichophora". Hence, this species is included in this genital morphotype.

Distribution
India (Bombay, Tamil Nadu; North India), Myanmar.    disc; anterior margin with short setae, without concavity at each lateral end; lateral margins smooth and glabrous, moderately sinuate at posterior half; anterior angles acute, not projected forward, elevated laterally; posterior angles obtuse. Prosternal process quadrangular-shaped. Scutellum glabrous, with punctures except lateral margins. Elytra with conspicuous pubescence on basal part, disc glabrous; epipleuron with pubescence except on apex. Foretibia with strong and sharp carina; insertion of inner spur closer third outer tooth than second one. Meso-and metatibia with transverse carina interrupted at middle, with a marked dorsal and ventral prominence; inner margin of dorsal surface with strong spines. Prepygidium regularly punctate, conspicuous short pubescence. Pygidium with punctures of irregular size and distribution; conspicuous pubescence on disc, longer toward apex; apical margin moderately widened and raised. Ventrites with conspicuous pubescence; ventrite 5 moderately depressed at posterior half, with pubescence longer on depressed part.  Keith (2005) transferred Rhizotrogus frontalis to Miridiba and synonymized it with M. castanea based on a series of male specimens labelled with the name of collector (Armand David). Indeed, , in the introduction of the work in which he described R. frontalis, thanked Armand David for the Coleoptera specimens received, which could suggest that the types of R. frontalis are these specimens labelled with the name of that collector. However,  indicated that the description of R. frontalis was based on only one specimen; therefore, the series studied by Keith (2005) cannot be syntypes. We have examined a male specimen of R. frontalis preserved in the collection of Léon Fairmaire (MNHN) labelled as a type and with an original label with his determination. Although  thought that this unique specimen was a female judging from its short antennal club, it is actually a male. In fact, and contrary to other Rhizotrogini, the species of Miridiba do no show obvious sexual dimorphism in the antennal club, which is very short in both sexes. On the other hand, we agree with the transfer of R. frontalis to Miridiba, the features of the external morphology and genitalia show that this species belongs to this genus. Moreover, the antenna 9-segmented and parameres with two dorsal and two ventral branches separated from each other, allow us include it in morphotype I "Trichophora". In contrast, we do not agree with the synonymy of Miridiba frontalis with M. castanea proposed by Keith (2005), who did not sufficiently justify this synonymy. We have compared the type of M. frontalis with those of M. castanea, finding them to differ by the following characters ( Table 2): head (pubescence on clypeus and frons, frontal carina), pronotum (anterior margin, anterior angles), the shape of the prosternal process, elytra (pubescence), foretibia (carina, inner spur), the protarsi and mesotarsi (tufts of setae), parameres (pubescence and granules at branches) and endophallus (internal structures). Accordingly, M. frontalis is established herein as valid species. The unique type specimen of M. frontalis  found in coll. Léon Fairmaire (MNHN) is a holotype by monotypy, and is labelled as holotype.

Remarks
Keith & Sabatinelli (2010) described Miridiba furcillata based on a series of 32 specimens, designating holotype, allotype and thirty paratypes. This species shows features of external morphology, which characterize Miridiba. Also, parameres with two dorsal and ventral branches separated from each other : figs 5-6) characterize morphotype I "Trichophora". Hence, this species is included in this genital morphotype.   and lectotype and paralectotype of M. castanea (Waterhouse, 1875

Remarks
Keith (2006) described Miridiba hanoiensis based on only one male specimen designated as holotype. This species shows features of external morphology that characterize Miridiba. On the other hand, the male genitalia described and illustrated by Keith (2006) do not provide enough data on the genital morphology, making it difficult to specify the morphotype to which this species belongs. Nevertheless, the acicular expansions at the base of the aedeagus described by Keith (2006), which could be ventral branches, and the antenna 9-segmented lead us to believe that this species could belong to morphotype I "Trichophora".

Remarks
Itoh (2001) described Miridiba hirsuta based on a male holotype and five paratypes (2 males and 3 females). According to the author (Itoh 2001), this species is closely allied to M. trichophora, but M. hirsuta is distinguishable by the larger size, sharper apices of upper branches of parameres, and antennal club weakly more elongate in male. We have studied five specimens (TMC) collected from the type locality and identified by Mr Matsumoto as M. hirsuta, observing some differences with the type of M. trichophora in endophallus. However, given that we were unable to examine the types of M. hirsuta, it is not possible to confirm that these differences characterize M. hirsuta. Until the types of M. hirsuta are studied, we consider it a valid species. According to the antenna 9-segmented and the parameres described by Itoh (2001), this species is included in this genital morphotype I "Trichophora".

Remarks
Miridiba huesiotoi was described based on the male holotype and eleven paratypes (5 males and 6 females) . According to the original description, M. huesiotoi can be separated from M. formosana by having pubescence on pronotum, elytra and scutellum hardly observable; apex of clypeus moderately bilobed; anterior angles slightly protuberant; metafemora slender, slightly broadened at middle; parameres with upper part curved downwardly, exceeding the end of the ventral branches extremely. In our opinion, features at the external morphology are not discrete enough to differentiate M. huesiotoi from M. formosana. 1) Setae on body distinctly short / distinctly long.
2) The apex of clypeus moderately bilobed / weakly bilobed. 3) Anterior angles of pronotum slightly protuberant / moderately protuberant. 4) Metafemora slender, slightly broadened at middle / expanded anteriorly and posteriorly. 5) Parameres with upper part curved / strongly curved. These differences found by Li et al. (2015) could be due to intraspecific variability of M. formosana. However, given that we were unable to examine the types of M. huesiotoi to study the variability of these characters or to compare them with the type of M. formosana; M. huesiotoi is considered a valid species until further investigation is done. Based on the 9-segmented antennae and the parameres described by Li et al. (2015), this species is included in this genital morphotype I "Trichophora".

Remarks
This species was transferred by Nomura (1977) without studying any type specimens. Coca-Abia (2008) studied and designated a lectotype and a paralectotype of M. hybrida, confirming its transfer to Miridiba. This species shows features of external morphology and male genitalia, which characterize morphotype I "Trichophora". Hence, this species is included in this genital morphotype.

Diagnosis
External morphology of adult (Fig. 44). Body size 21.5 mm. Dorsal surface glabrous, at most, with short setae in each puncture hardly visible. Clypeus concave, with anterior edge moderately emarginate at middle. Frons very sloping, strong carina sunk at middle. Pronotal anterior margin sloped forward with a row of punctures, glabrous or, at most, some short setae at sides, with a slight concavity at each lateral end; posterior margin glabrous, finely flanged except at middle; lateral margins smooth, glabrous, convergent and elevated at anterior half, moderately sinuate at posterior half; anterior angles acute, not projected forward; posterior angles obtuse and rounded. Prosternal process cone-shaped. Scutellum glabrous, with punctures except on sides. Elytra with punctures regularly distributed, less densely punctate than pronotum; epipleuron with pubescence in basal half. Foretibia in male with insertion of inner spur equidistant between second and third outer tooth, with strong dorsal carina. Meso-and metatibia with transverse carina interrupted at middle; inner margin of dorsal surface with spines. Prepygidium regularly punctate, with conspicuous pubescence in lateral view. Pygidium with short and decumbent pubescence, longer on apex; irregularly punctate, punctures thinner and denser at dorsal margin; apex pointed with thick and rough punctures; apical margin thicker and moderately raised. Ventrite 5 moderately depressed at posterior half, which has strong punctures; longer pubescence on depressed area. Anterior margin of ventrite 6 bulging at middle, bulge without pubescence. Male genitalia. Parameres (Fig. 45) glabrous; dorsal branches thin and elongated, starting below collum; distal margin of collum bilobed in dorsal view, raised in relation to dorsal branches. Ventral branches joined at proximal end forming a semi-circle, apices thin and slightly curved outwards. Endophallus ( Fig. 46) with spines arranged helicoidally around internal walls of sac and soft sensillae at distal end. Apophysis of temones (Fig. 46) widened and joined at distal end. Female unknown.

Remarks
Brenske (1899) did not indicate how many specimens used in describing Holotrichia imitatrix. We have studied a male specimen conserved in the Brenske collection (MFNB) labelled as syntype and identified as Neodontocnema imitatrix by Frey (1971). Although Brenske (1899) specified that this specimen was a female, probably based on the short antennal club, it is a male. As stated above, this confusion is attributable to the absence of sexual dimorphism in the antennal club. One syntype specimen of M. imitatrix found in MFNB is designated as the lectotype herein. Miridiba imitatrix is very similar to M. tuberculipennis . Still, it is possible to distinguish them by the metatibial transverse carina, the apex of the pygidium, ventrite 6 and male genitalia. The antenna 9-segmented and parameres with two dorsal and two ventral branches separated from each other, allow us to include it in morphotype I "Trichophora".  Miridiba kuatunensis Gao & Fang in Gao et al., 2018: 4,

Diagnosis
See Gao et al. (2018). Gao et al. (2018) described Miridiba kuatunensis based on a male holotype and fifteen paratypes (eight males and seven females) conserved in IZCAS. The 9-segmented antenna, pronotal surface densely punctate and parameres with two dorsal and two ventral branches (Gao et al. 2018: fig. 2) allow us to include M. kuatunensis in morphotype I "Trichophora". Miridiba kuatunensis is a species related to M. brancuccii, the parameres shape illustrated by Sabatinelli (1983: figs 1-2) shows similarities with those of M. kuatunensis (Gao et al. 2018: fig. 2h-i). However, these species differ in the dorsal surface of the body, glabrous in M. brancuccii (Sabatinelli 1983) and pubescent in M. kuatunensis. On the other hand, M. kuatunensis and M. pilosella (Moser, 1908) are quite similar, both species can be distinguished by the ratio between dorsal and ventral branches of the parameres and the curving of dorsal branches tips .

Remarks
We were unable to examine any type specimens of Miridiba newari. However, the original description and illustration of male genitalia given by Sabatinelli & Migliaccio (1982) prove that this species belongs to Morphotype I "Trichophora".

Diagnosis
External morphology of adult (Itoh 1995;Gao et al. 2018

Remarks
Itoh (1995) described the subspecies Miridiba tuberculipennis obscura base on a male holotype, a female allotype and thirteen paratypes (three males and ten females) from Thailand and Laos. According to Itoh (1995), the subspecies is distinguishable by robust and shorter parameres branches of male genitalia and variability in intensity of coloration of elytral tubercles. After studying two paratypes deposited in MFNB and additional non-type specimen from China, Gao et al. (2018) elevated this subspecies to species rank as Miridiba obscura according to parameres and clypeus shape (Gao et al. 2018: fig. 5).
Male genitalia indicates that this species is characteristic of the morphotype I "Trichophora". Hence, this species is included in this genital morphotype.

Diagnosis
External morphology of adult (Fig. 51). Body size 17.4-19.0 mm. Dorsal surface with conspicuous short pubescence. Clypeus flat with anterior edge moderately emarginate at middle, oblique laterally. Frons with sharp carina, not interrupted at middle. Pronotal anterior margin with short setae, without concavity at lateral ends; posterior margin glabrous; lateral margins strongly serrated with short setae; anterior angles acute almost right, rounded, not projected forward; posterior angles obtuse and rounded. Prosternal process with a ventral bulge and posterior margin rounded. Scutellum densely punctate. Elytra with punctures regularly distributed, more scattered and larger than those of pronotum; epipleuron with long marginal setae except on apex. Foretibia with sharp dorsal carina, insertion of inner spur closer third outer tooth than second one. Meso-and metatibia with interrupted and complete transverse carina, respectively; inner margin of dorsal surface with strong spines. Pygidium with rough punctures, dense pubescence and irregular in length. Abdominal ventrites covered with dense, short and decumbent setae and punctures regularly distributed. Male genitalia: parameres ( Fig. 52) with sparse setae on ventral side of dorsal branches and on dorsal side of ventral ones; in lateral view dorsal branches moderately bent at two stretches towards apices, which are curved downward with a small apical tip; ventral branches with apices curved outward. Endophallus (Fig. 53) with spines arranged helicoidally around internal walls towards distal end, with a raspula of dark sensillae at proximal half of sac. Apophysis of temones ( Fig. 53) with distal ends separated from each other. Female genitalia as describe at morphotype I. Genital chamber with a pair of vestigial sternites reduced to few sensillae, median oviduct very developed with hardened epithelium and dark sclerotized areas (Fig. 54).

Remarks
Moser (1908) did not indicate the number of specimens used in describing Holotrichia pilosella. We have studied a series of specimens (MFNB), two of them labelled as types by the author and another five specimens with the same collection data, which belong to the type series. We designate the lectotype and five paralectotypes. On the other hand, Miridiba formosana (Moser, 1909) was transferred to Miridiba by Nomura (1977), and a lectotype and two paralectotypes were studied and were designated by Coca-Abia (2008). After studying the types of M. pilosella, we noted that features of the external morphology and male genitalia of M. formosana (Moser, 1909) (Coca-Abia 2008) match well those of M. pilosella. These characters are body pubescence (short and decumbent), head (clypeus shape, frontal suture and carina), pronotum (pubescent anterior margin, crenulate and pubescent lateral margins), foretibiae (strongly carinate), pygidium (conspicuous punctures and pubescence), male genitalia (parameres shape, internal structures of endophallus and temones shape). Therefore, we here synonymize M. formosana with M. pilosella and include it in morphotype I "Trichophora", from its antenna 9-segmented and male and female genital morphology.

Remarks
Keith & Sabatinelli (2010) described Miridiba recta based on a male holotype. We were unable to examine the type specimen of Miridiba recta. However, according to the original description, this species shows features of the external morphology that characterize Miridiba. Besides, the parameres show two dorsal and two ventral branches separated from each other (Keith & Sabatinelli 2010: figs 8-9), which characterize morphotype I "Trichophora". Hence, this species is included in this genital morphotype.

Thailand (Doi Sanjac).
Miridiba sus  Figs 55-56 Holotrichia sus  External morphology (Fig. 55) and parameres (Fig. 56) Itoh (1995) transferred this species to Miridiba and synonymized it with Hippotrichia hainana Arrow, 1948without justification. Coca-Abia (2008 studied the types and indicated holotypes for M. sus (MFNB) and H. hainana (BMNH). However,  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.

Remarks
Miridiba taipei was described based on a male holotype and seven type specimens (six males and one female) . According to the original description, M. taipei can be separated from the similar species M. trichophora and M. hirsuta by having three distinctive morphological characters at the apex of clypeus, anterior margin of pronotum and parameres. We were unable to examine the types of M. taipei but, according to the 9-segmented antenna and shape of parameres, this species is included in this genital morphotype I "Trichophora".

Remarks
Li et al. (2015) described Miridiba taoi based on a male holotype and two male paratypes. We were unable to examine the types of M. taoi to study its characters. Hence, M. taoi is considered a valid species. According to antenna 9-segmented and parameres  this species is included in genital morphotype I "Trichophora".

Diagnosis
External morphology of adult (Fig. 57). Body size 20.5 mm. Dorsal surface glabrous, at most, with tiny setae in each puncture hardly visible. Clypeus shorter than frons, concave, oblique sides, with anterior edge emarginate at middle. Frons with strong carina. Pronotal anterior margin widely flanged, with a perpendicular anterior face glabrous, with concavity at each lateral end; posterior margin, glabrous, finely flanged except at middle; lateral margins smooth and glabrous, elevated at fore half; anterior angles acute, not projected forward; posterior angles obtuse and rounded. Prosternal process coneshaped. Scutellum with dense punctures except at lateral sides. Elytra with dense punctures except on sutural costae; epipleuron with pubescence on basal half. Foretibia with develop dorsal carina. Mesoand metatibia with complete transverse carina moderately developed; inner margin of dorsal surface with sparse but conspicuous spines. Prepygidium regularly punctate and with short pubescence. Pygidium irregularly punctate, with conspicuous pubescence longer on apex. Ventrite 5 moderately depressed at posterior half, with pubescence on surface, longer on depressed part. Ventrite 6 with anterior margin bulky and without punctures, posterior half moderately concave with long pubescence. Male genitalia: parameres (Fig. 58) without pubescence; dorsal branches and collum continuous, apices convergent; ventral branches with apices moderately bent outwards. Endophallus (Fig. 59) arising from middle of temones apophysis, short, thin and with spines at distal end. Apophysis of temones (Fig. 59) very long and strongly sclerotized separated from each other at distal end, with a distal membrane at apices armed with spines. Female genitalia not studied.   described Miridiba thai based on three specimens, two males and one female, and designated a holotype, a paratype and an allotype, respectively. We have studied the holotype and verified that this species shows features of external morphology that characterize Miridiba. Besides, the parameres show two dorsal and two ventral branches separated from each other (Keith 2010: figs 5-6) and antenna 9-segmented (not 10-segmented as was specified in the original description of Keith 2010), which characterize morphotype I "Trichophora". Hence, this species is included in this genital morphotype.
Neodontocnema tuberculipennis -Arrow 1948: 51 (combination). strongly convergent and elevated at anterior half; anterior angles acute, not projected forward; posterior angles obtuse and rounded. Prosternal process cone-shaped. Scutellum glabrous, with punctures except at sides. Each elytron with a wart on apex only in females; epipleuron with setae at basal half. Foretibia with insertion of inner spur closer to third outer tooth than second one in females, in males almost equidistant between both outer teeth; with moderate carina. Mesotibia with transverse carina interrupted at middle in females, complete in males. Metatibia with transverse carina complete in both sexes; inner margin of dorsal surface with spines. Prepygidium roughly punctate and pubescent. Pygidium pubescent, irregularly punctate, truncated cone shaped, blunt, and apical margin moderately raised. Ventrite 5 moderately depressed at posterior half with pubescence longer on depressed part. Ventrite 6 moderately concave and bulging at anterior margin. Male genitalia: parameres (Fig. 61) without pubescence, dorsal branches starting slightly below collum, long, thin and ventrally curved, apices of ventral branches bent outwards ninety degrees. Endophallus (Fig. 61) asymmetrical in lateral view, with a dorsal part armed with a very strong spine and a ventral part with numerous setae. Apophysis of temones with distal ends separated from each other. Female genitalia (Fig. 62): genital chamber with vestigial sternites reduced to an area with a few sensillae. Median oviduct reduced with epithelium not sclerotized placed behind peduncle of bursa copulatrix that is strongly sclerotized.

Remarks
Neodontocnema ardoini was described based on only one female specimen from Vietnam (Frey 1970). The external morphology described by Frey (1970) led Keith (2006) to consider the transfer of N. ardoini to Miridiba. Later,  synonymized M. ardoini with M. tuberculipennis after studying the type of M. ardoini and two non-type specimens of Miridiba from Vietnam (male and female), concluding that the features of these two specimens, female and male, matched well those of M. ardoini and M. tuberculipennis, respectively. However, to establish this synonymy, types of M. tuberculipennis should also have been studied. In this work, we have studied types of M. ardoini and M. tuberculipennis and verified that features of the external morphology and female genitalia that characterize M. tuberculipennis are present in M. ardoini. Therefore, we confirm the synonymy of M. ardoini with M. tuberculipennis, and we include this species into morphotype I "Trichophora". In addition, two further former syntypes of M. tuberculipennis are recognised as paralectotypes (BMNH), and the unique female specimen of M. ardoini is labelled as holotype (NHMB).

Diagnosis
External morphology of adult (Fig. 63). Body size 16.5-17.2 mm. Dorsal surface densely pubescent. Clypeus shorter than frons, with anterior edge moderately emarginate at middle, oblique laterally. Frons with carina bent backward at middle. Pronotal anterior margin with short setae and without concavity at each lateral end; posterior margin finely flanged; lateral margins strongly serrated, with short setae and moderately reflexed upwards; anterior and posterior angles obtuse. Prosternal process nearly trapezoidal-shaped. Scutellum pubescent. Elytra with pubescence, longer on basal surface; insertion of inner spur closer to second outer tooth than third one in male. Meso-and metatibia with interrupted and complete transverse carina, respectively; inner margin of dorsal surface with spines. Prepygidium densely punctate. Pygidium pubescent, roughly and irregularly punctate. Ventrites with dense, short and decumbent setae; ventrite 5 with long pubescence; ventrite 6 moderately concave and bulging at anterior margin. Male genitalia: parameres ( Fig. 64) with dorsal branches and collum continuous, apices downward; ventral branches with apices moderately curved upwards. Female genitalia not studied.

Diagnosis
External morphology of adult (Fig. 65). Body size 18.6 mm. Dorsal surface glabrous, shiny appearance. Clypeus shorter than frons, flat, oblique sides, anterior edge strongly emarginate at middle. Frons with carina moderately developed. Pronotal anterior margin glabrous, moderately wavy forward just behind eyes; posterior margin glabrous, finely flanged with a row of punctures except at middle; lateral margins moderately serrated almost smooth with a few short setae; anterior and posterior angles obtuse, anterior angle not projected forward. Prosternal process cone-shaped. Scutellum glabrous, with scattered punctures and sides without punctures. Elytra with punctures bigger than those of pronotum, epipleuron with a few short setae at basal part. Foretibia with dorsal carina moderately developed; insertion of inner spur closer to third outer tooth than second one. Meso-and metatibia with transverse carina interrupted at middle and complete, respectively; inner margin of dorsal surface with few spines. Prepygidium and pygidium with scattered punctures and glabrous, pygidium with apical margin pubescent, widened and moderately raised. Ventrites 3 and 4 with inconspicuous punctures and glabrous. Ventrite 5 not depressed at posterior half, with pubescence of different length, with conspicuous scattered punctures. Ventrite 6 moderately bulging at anterior margin, with long pubescence near posterior margin. Male and female genitalia as described above (genital morphotype II "Gressitti"). Male genitalia: parameres ( Fig. 5) with all branches of dorsal complex shorter than ventral branches. Endophallus (Fig. 6) with a strong raspulae with numerous setae. Female genitalia (Fig. 7).  Frey (1970) described Holotrichia gressitti based on three female specimens designated as a holotype and two paratypes, remaining the male unknown. We have studied one paratype (NHMB) which shows external morphology characteristic of Miridiba. Moreover, female genitalia has features not shared with species of other genital morphotypes. Hence, the female genitalia of morphotype II "Gressitti" was described based on this species (Fig. 7). Moreover, the male genitalia of M. gressitti is described based on a paratype of Miridiba herteli (see remarks under M. herteli), which is described in morphotype II "Gressitti" (Figs 5-6).

Laos (Vientiane).
Miridiba herteli (Frey, 1971) Figs 66-68 Holotrichia herteli Frey, 1971: 220-221, fig. 29b (Fig. 67). Endophallus with a soft raspula with scattered small spines (Fig. 68). Apophysis of temones with each distal end prolonged by an oval plate each weakly sclerotized (Fig. 68). Female genitalia unknown.  Frey (1971) described Holotrichia herteli from two specimens, male and female, designated as holotype (SNSD) and paratype (NHMB), respectively. Later,  transferred this species to Miridiba. We have studied both type specimens and realized that the paratype is not female but male. In addition, after comparing both types, we have found that they differ by the following characters (Table 3): body (size, appearance and pubescence), pronotum (anterior and lateral margins), foretibia (carina, inner spur), mesotibia (lateral carina), pygidium (apical margin), ventrites 5 and 6 (appearance) and male genitalia (parameres shape and internal structures of endophallus). These differences between the holotype and paratype of M. herteli raise questions about the identity of the paratype. However, after studying and comparing the paratypes of M. herteli and M. gressitti, they turned out to be identical. Consequently, the paratype of M. herteli is identified as M. gressitti; features of external morphology confirm it (Table 3). Therefore, the male genitalia of M. gressitti is described based on the paratype of M. herteli, detailed above (morphotype II "Gressitti"). The holotype of M. herteli is considered to belonging to genital morphotype II "Gressitti". The features of male genitalia described below confirm it.

Species included in Morphotype III "Leucophthalma"
The group is composed of three species, which are characterized by antenna 10-segmented, pronotal surface densely punctate (distance between punctures equal or smaller than diameter of a puncture) and male and female genitalia as specified above. (Wiedemann, (Frey, 1971) and paratype of M. gressitti (Frey, 1970 fig. 17): Parameres ( Fig. 8) with dorsal branches shorter than ventral ones, wrinkled at distal end. Endophallus with strong spines, larger towards distal end, placed helicoidally surrounding internal walls of sac. Temones reduced, apophysis separated at distal end. Female genitalia not studied.

Remarks
Coca-Abia (2008) studied this species and transferred it to Miridiba. Miridiba leucophthalma shows features of external morphology and male genitalia that characterize morphotype III "Leucophthalma". Hence, this species is included in this genital morphotype.

Diagnosis
External morphology of adult (Fig. 69). Body size 23-25 mm. Dorsal surface glabrous, shiny appearance. Clypeus flat, oblique sides, anterior edge emarginate at middle. Frons with continuous carina. Pronotal surface densely punctate; anterior margin glabrous, narrowed at middle and at sides, without concavities at lateral ends; posterior margin glabrous, at most with very short setae at sides; lateral margins smooth, glabrous and with anterior third reflexed upwards; anterior and posterior angles almost right and rounded, respectively. Elytra shiny, punctures denser at base than apices; epipleuron with a few short setae at basal part. Foretibia with gently carina. Meso-and metatibia with incomplete transverse carina; inner margin of dorsal surface without spines. Pygidium heart-shaped, densely punctate, with a central depression in male; pygidium concave, moderately punctate and with two strong pointed protuberances in females, glabrous, only short setae along apical margin at both sexes. Ventrites 3 and 4 with sparse pubescence and inconspicuous punctures. Ventrite 5 strongly depressed at posterior half in males; moderately depressed in females, with pubescence of different length at both sexes, with conspicuous punctures. Ventrite 6 bulging anteriorly, with long pubescence near posterior margin. Male genitalia: parameres ( Fig. 70) with short dorsal branches separated each other and blunt apices; ventral branches longer than dorsal ones, divergent, arcuate, each one with a spine at proximal position. Endophallus covered with sensilla, denser at distal end, without spines (Fig. 71). Female genitalia (Fig. 72). Gonopore fold with a strong quadrangular sensory plate. Vestigial sternites reduced with sensillae.

Remarks
Matsumoto (2016) studied three syntypes of Holotrichia dohrni (two males and one female), transferred this species to Miridiba and considered M. dohrni closely allied to Miridiba gravida (Sharp, 1881). We have studied three syntypes (MFNB) and designated them as a lectotype and two paralectotypes. Also, we agree with the transfer of H. dohrni to Miridiba and the similarities between M. leucophthalma and M. gravida. Male genitalia matches morphotype III "Leucophthalma" above described. Hence, this species is included in this genital morphotype.

Material examined
Lectotype of H. moffartsi (here designated) INDONESIA • ♂; "Sumatra"; "Lectotype Miridiba moffartsi (Sharp, 1881) CH. Bu Gao det. 2017"; MFNB.  redescribed Holotrichia gravida and Coca-Abia (2008) transferred it to Miridiba. In the original description, Sharp (1881) indicated that this species is closely allied to M. leucophthalma. We have not studied type specimens of H. gravida, but, after reviewing the redescription by , we agree with Sharp (1881) and include this species in morphotype III "Leucophthalma". On the other hand, Brenske (1900) also considered H. moffartsi belonging to Leucophthalma group. The first author of this paper has studied and compared a syntype of H. moffartsi (MFNB) with the genitalia illustrations of M. gravida , verifying the synonymy proposed by this author . Also, the syntype of H. moffartsi (MFNB) is designated as lectotype herein.

Species included in Morphotype IV "Bidentata"
The group is composed of seven species, which are characterized by antenna 10-segmented, pronotal surface densely punctate (distance between punctures equal or smaller than diameter of a puncture), and male and female genitalia as specified above. (Burmeister, 1855

Diagnosis
External morphology of adult of M. behrensi (Fig. 73). Body size 19.8-20.5 mm. Dorsal surface glabrous. Clypeus shorter than frons, moderately concave, oblique lateral sides, anterior edge deeply emarginate at middle. Frons with strong carina interrupted at middle. Pronotum with anterior margin glabrous, strongly flanged, thinner at middle and absent at lateral ends; posterior margin glabrous; lateral margins glabrous, moderately crenulated with anterolateral part gently flexed upwards; anterior angles obtuse and marked, not projected forward, posterior angles obtuse and strongly rounded. Prosternal process arrowhead-shaped. Scutellum glabrous, heart-shaped. Elytra more densely punctate at base than at apices; epipleuron glabrous. Foretibia with dorsal carina moderately developed; insertion of inner spur closer to third outer tooth than second one. Meso-and metatibia with transverse carina interrupted at middle and complete, respectively, inner margin of dorsal surface with small spines. Prepygidium irregularly punctate, anterior area finely wrinkled with small punctures among wrinkles, posterior area coarsely punctate, glabrous. Pygidium surface with scattered punctures irregularly distributed, surface glabrous, at most with short setae in each puncture hardly visible, with pubescence on apical margin. Ventrites conspicuously punctate. Ventrite 2 with pubescence, short, reclined, thick and whitish. Ventrites 3 and 4 glabrous. Ventrite 5 moderately depressed at posterior half, with pubescence longer and punctures denser at depressed area. Male genitalia as described in morphotype IV "Bidentata". Parameres ( Fig. 9) with dorsal branch narrowed at apex, with a rounded tip curved downward. Ventral branches with elevations as waves at outer margin, apices expanded. Endophallus (Fig. 10) without raspulae, with two strong spines at distal end and other four smaller along sack. Apophysis of temones short with distal ends extend laterally surrounding endophallus partially (T-shaped) (Fig. 10). Female unknown.

Remarks
Matsumoto (2011) studied a series of male and female specimens collected from Malaysia, Thailand and Sumatra, and identified them as Holotrichia bidentata. Although the type specimens were not inspected, Matsumoto (2011) transferred this species to Miridiba. Later, Matsumoto (2016) synonymized Holotrichia behrensi Brenske, 1892 with Miridiba bidentata after studying the types of H. behrensi only. We have examined a male specimen, preserved in collection MLUH with the genitalia in poor condition, identified as H. bidentata by an old handwritten label. Burmeister (1855) described this species from Java as belonging to Ancylonycha. The fact that the type locality (Java) does not appear on any labels, and the identification on the old handwritten label is H. bidentata and not A. bidentata casts doubt on whether it is a type specimen. Thus, we consider that the specimen of H. bidentata from MLUH is not a type. Then, it is not possible to confirm or reject the transfer of H. bidentata to the genus Miridiba (Matsumoto 2011), or the synonymy of H. behrensi with A. bidentata (Matsumoto 2016) until types of A. bidentata are studied. Therefore, we maintain the taxonomic status of H. bidentata and M. behrensi as currently established (Matsumoto 2011(Matsumoto , 2016. We establish the genital morphotype IV "Bidentata" based on male characters of M. behrensi. On the other hand, we have studied two male syntypes of H. behrensi from MFNB and they show features that characterize the genus Miridiba. Moreover, we designate them as lectotype and paralectotype herein.

Diagnosis
External morphology of adult (Coca-Abia 2008). Dorsal surface glabrous. Clypeus with anterior edge depressed at middle and elevated. Pronotum with anterior margin strongly flanged; posterior margin finely flanged except at middle; lateral margin weakly serrated with few setae; anterior angles almost right, not projected forward or upward, posterior angles obtuse and strongly rounded. Elytra with shiny appearance, weakly punctate, almost without punctures at apices, elytral apices strongly truncate. Foretibia with carina moderately developed. Meso-and metatibiae with transverse carina interrupted at middle, inner margin of dorsal surface with few small spines. Pygidium glabrous, with pubescence on apical margin. Male genitalia: parameres very similar to those of M. behrensi, with dorsal branch narrowed at apex. Ventral branches with elevations as waves at outer margin, apices expanded. Endophallus with spines thicker and stronger at proximal half. Female genitalia not studied.

Remarks
Coca-Abia (2008) studied the species and designated lectotype and paralectotype (MFNB) (these types were lost on the way back to MFNB). This species shows features of external morphology and genitalia that characterize the morphotype IV "Bidentata". Hence, this species is included in this genital morphotype.

Diagnosis
External morphology of adult (Coca-Abia 2008). (Type specimen without head and pronotum). Elytra shiny, glabrous and disperse punctures, weakly punctate at apices. Pygidium with pubescence only on apical margin. Meso-and metatibiae with complete transverse carina, inner margin of dorsal surface without spines. Male genitalia: parameres (Coca-Abia 2008: fig. 18) with dorsal branch wide at all its length with sutural scar at middle. Ventral branches symmetrical, thin, without wavy elevations at outer margin, widened apices with rough appearance. Female unknown.

Remarks
This species was transferred to Miridiba by Keith (2006) and the holotype was indicated by Coca-Abia (2008). However,  did not indicate how many specimens he studied, so the indication that the specimen was a holotype by Coca-Abia (2008) was not correct (Art. 73.1 ICZN) (this specimen indicated as holotype was lost on the way back to MFNB). Miridiba longula shows features of the external morphology and genitalia that characterize morphotype IV "Bidentata". Hence, this species is included in this genital morphotype.

Distribution
Vietnam.

Remarks
Matsumoto (2011) transferred this species to Miridiba based on several non-type specimens from Malaysia. We were unable to examine type specimens and it is not possible to confirm or disprove the transfer of H. malaccensis to the genus Miridiba (Matsumoto 2011) until the types are studied. Then, we consider the taxonomic status of H. malaccensis as it is currently established (Matsumoto 2011) and, according to figures of the male genitalia (Matsumoto 2011: fig. 12), we include this species in the morphotype IV "Bidentata".

Material examined
Lectotype (   described Holotrichia saigonensis with a series of specimens from Cochinchina. Keith (2006) transferred this species without studying the types nor giving any justification. After studying seventeen specimens (MFNB) including two types, we agree with the transfer of H. saigonensis to Miridiba. Features of external morphology and genitalia prove that this species belongs to this genus. Moreover, the parameres with one dorsal and two ventral branches allowing us include this species in genital morphotype IV "Bidentata". On the other hand, we have designated two syntypes as lectotype and paralectotype. After comparing these two types of M. saigonensis, we have noted that they differ from each other. The differences between them lie in the clypeus (more concave and deeply emarginate in lectotype than in paralectotype), frons (surface depressed laterally in lectotype and without depressions in paralectotype), and parameres (dorsal branch flat and wider in the lectotype, in the paralectotype narrower and with a dorsal depression). In addition to that, we have compared the paralectotype of M. saigonensis with types of M. behrensi and they are very similar to each other. Currently, M. behrensi is a synonym of M. bidentata (Matsumoto 2016), but it is not possible to compare the paralectotype of M. saigonensis with M. bidentata until types are studied. Then, we only can assert that the paralectotype of M. saigonensis is very similar to M. behrensi. Moreover, four other specimens, of seventeen studied, differ from the lectotype of H. saigonensis, and are also identified as M. behrensi in this study. Male and female genitalia of M. saigonensis shows features that characterize morphotype IV "Bidentata". Hence, this species is included in this genital morphotype.

Diagnosis
External morphology of adult (Fig. 77). Dorsal surface glabrous. Clypeus concave, shorter than frons, oblique laterally, anterior edge strongly emarginate at middle. Frons with sharp carina. Anterior pronotal margin glabrous, strongly flanged, narrowed at middle and at lateral ends; posterior margin glabrous, moderately flanged; lateral margins smooth, glabrous, moderately elevated at anterior half; anterior angles almost right and rounded, not projected forward; posterior angles obtuse and rounded. Pronotal surface densely punctate, each puncture with a tiny bulge hardly visible. Scutellum sparsely punctate. Elytral surface with punctures regularly distributed; each puncture with a tiny bulge hardly visible; apical callus well defined; epipleuron glabrous with membrane. Foretibia with a moderately developed dorsal carina; insertion of inner spur closer to third outer tooth than second one. Meso-and metatibia with transverse carina interrupted and complete respectively; inner margin of dorsal surface with few spines. Pygidium irregularly punctate; punctures thinner at anterior margin; surface without conspicuous pubescence, at most with tiny setae in each puncture hardly visible, apical margin with long pubescence. Ventrites 2, 3 and 4 without conspicuous pubescence, with small scales hardly visible. Ventrite 5 moderately depressed at posterior half with punctures uniformly distributed and long pubescence irregularly distributed on posterior half; anterior half without conspicuous pubescence. Ventrite 6 moderately bulging anteriorly; conspicuous pubescence irregularly distributed. Male genitalia (Fig. 78): dorsal branch of parameres thin and symmetrical, with sutural scar completely fused, triangular at proximal end, tapered with a rounded tip curving downward at distal end. Ventral branches with elevations as waves at outer margin, apices upward. Endophallus and temones not studied. Female genitalia: median oviduct with wrinkled and hardened epithelium; elongate plates of gonopore fold with sensillae; conspicuous vestigial sternites placed ventrally at gonopore.

Diagnosis
External morphology of adult (Fig. 79). Body size 24-26 mm. Dorsal surface glabrous. Clypeus with conspicuous punctures, concave, shorter than frons, oblique laterally, anterior edge strongly emarginate at middle. Frons with punctures similar those of clypeus; frontal carina sharp, slightly bent backward and depressed at middle. Anterior pronotal margin glabrous, strongly flanged, narrowed at middle and lateral ends; posterior margin glabrous, finely flanged; lateral margins glabrous, smooth, moderately elevated at anterior half; anterior angles obtuse and rounded, not projected forward; posterior angles obtuse and marked. Prosternal process tongue-shaped. Scutellum without punctures at middle line. Elytral surface with punctures regularly distributed, each puncture with a tiny bulge; apical callus well definite; epipleuron glabrous. Foretibia with a moderately developed dorsal carina. Meso-and metatibia with a moderately developed transverse carina interrupted and complete, respectively; inner margin of dorsal surface with few small spines. Prepygidium with punctures irregularly distributed, more scattered at posterior margin; with pubescence short and decumbent, inconspicuous at posterior part. Pygidium irregularly punctate; surface without conspicuous pubescence, at most with tiny setae in each puncture hardly visible, apex with long pubescence. Ventrite 1 with posterior margin visible, enduring strong and short pubescence. Ventrite 2 with conspicuous short pubescence, decumbent and regularly distributed. Ventrites 3 and 4 without conspicuous pubescence. Ventrite 5 moderately depressed at posterior half; punctures and pubescence irregularly distributed; with a row of long pubescence at middle. Ventrite 6 moderately bulging anteriorly; conspicuous punctures and pubescence long and short irregularly distributed. Male genitalia: dorsal branch of parameres symmetrical, with sutural scar completely fused, cleft and a fan-shaped extension at distal end (Fig. 80A, C). Ventral branches close to each other, with elevations at outer margins little developed, apices upward, with a small membranous area close to phallobase (Fig. 80B). Phallobase shorter than paramere. Endophallus (Fig. 81) strongly armed with small spines at middle of sac; distal end with two strong spines at lateral sides of two placoid raspulae; proximal end with numerous acicular soft setae. Apophysis of temones short with ends extend laterally surrounding endophallus partially (T-shaped) (Fig. 81). Female genitalia as described for morphotype IV "Bidentata" (Fig. 82).

Material examined
Lectotype (here designated) BRUNEI • ♂; "N. Borneo Brunei Waterstradt S."; "Holotrichia waterstradti Type ♂ Mos"; "SYNTYPE Holotrichia waterstradti Moser 1912 labelled by MFNB 2017"; "Lectotype Miridiba waterstradti    described Holotrichia waterstradti from a series of specimens from Borneo (Brunei) collected by Waterstradt. Matsumoto (2011) transferred this species based on a non-type male specimen from the westernmost part of Borneo Island. After studying four type specimens (MFNB) (one male and three females), we agree with the transfer of H. waterstradti to Miridiba. Moreover, male and female genitalia allow us to consider this species to belong to morphotype IV "Bidentata". We designate lectotype and paralectotypes of M. waterstradti herein.

Remarks
Hope (1842) described briefly Holotrichia sinensis with specimens from Chusan and Canton sent to England by Dr Cantor. Subsequently, Hope (1843Hope ( , 1845 republished the species a little more detailed. Burmeister (1855) included this species in Ancylonycha and synonymized Ancylonycha sinae Blanchard, 1850with A. sinensis. Later, Reitter (1902 described the subgenus Pledina considering H. sinensis as the type species, remaining as H. (Pledina) sinensis until Nomura (1977) transferred it to Miridiba. We have studied four specimens of H. sinensis (BMNH) (three males and one female, including a male type), and have verified that these specimens show features that characterize Miridiba. However, male genitalia shows features not shared with species belonging to other genital morphotypes of Miridiba. Hence, we describe the male genitalia morphotype V "Sinensis" based on this species. On the other hand, Keith (2006) synonymized Rhizotrogus cribellatus Fairmaire, 1891 with M. sinensis transferring it to Miridiba. We have studied two type specimens (male and female) of R. cribellatus (MNHN) and have confirmed the synonymy. Besides, after studying the unique type specimen (female) (NHMB) used by Frey (1970) to describe Holotrichia dalatensis, and comparing its external morphology and female genitalia with that of M. sinensis, we have concluded that the features that characterize M. sinensis are also present in M. dalatensis. Therefore, we transfer H. dalatensis to Miridiba and synonymize it with M. sinensis. The female genitalia of morphotype V "Sinensis" is described based on H. dalatensis type. Hope (1842Hope ( , 1843Hope ( , 1845 never indicated how many specimens of H. sinensis were studied; in case other types are found, this unique syntype of M. sinensis is designated as the lectotype. We also designate the lectotype of M. cribellatus, which was not designated before, and a paralectotype is indicated. Moreover, the unique specimen of M. dalatensis used by Frey (1970) in describing H. dalatensis is a holotype by monotypy, and is labelled as holotype.

Remarks
Keith (2020) described Miridiba (Pledina) axanensis based on the male holotype and two paratypes (one male and one female). The characters antenna 10-segmented, pronotal surface densely punctate and collum with a membranous area in dorsal view (Keith 2020: figs 4-6), similar to other species of the morphotype V "sinensis", allow us to include M. axanensis in this morphotype V. On the other hand, in this species the lateral fusion of dorsal and ventral branches is partial. The lateral membrane joins the proximal part of the branches, showing the distal ends separated at lateral view.

Diagnosis
External morphology of adult (Fig. 84   described Miridiba pseudosinensis with two specimens designated as holotype and paratype. This species shows features of external morphology, which characterize Miridiba. Besides, male genitalia shows features that characterize the morphotype V "Sinensis". Hence, this species is included in this genital morphotype.

Remarks
Keith (2020) described Miridiba (Pledina) quasisinensis based on the male holotype and four paratypes (three male and one female). The characters antenna 10-segmented, pronotal surface densely punctate and collum with a membranous area in dorsal view (Keith 2020: figs 2-3), similar to M. sinensis and M. pseudosinensis, allow us to include M. quasisinensis in the morphotype V "sinensis". In addition, the presence of a membranous lateral area joining the dorsal and ventral branches laterally proves the lateral fusion process of these branches. The fusion process is from partial in M. axanensis until the complete fusion observed in M. quasisinensis with membrane without sclerotization and M. sinensis and M. pesudosinensis completely sclerotized with scars.

Distribution
Vietnam.

Species included in Morphotype VI "Borneensis"
The group is composed of two species, which are characterized by antenna 10-segmented, pronotum with scattered punctures (distance between punctures greater than diameter of puncture), pronotal surface depressed just behind anterior margin, metacoxa with whitish scales, and male and female genitalia as specified above. Matsumoto (2005) transferred Holotrichia borneensis Moser, 1918 andHolotrichia coxalis Arrow, 1944 to the genus Pentelia Brenske, 1891. However, both species showed differences with Pentelia discendens (Sharp, 1881) (type of Pentelia) in the shape of parameres and antennal club. After studying type specimens of P. borneensis and P. coxalis, both species show features of external morphology that characterize the genus Miridiba (pubescence of the mentum, labrum shape, frontal carina, tuft at tarsal segments and carina on foretibiae). Hence, we transfer these two species to the genus Miridiba. On the other hand, the presence of genital characters not shared with other Miridiba species leads us to propose the morphotype VI "Borneensis". (Moser, 1918) comb. nov. Figs 15, 87 Holotrichia borneensis Moser, 1918: 317 (type loc.: Borneo, Malaysia).

Diagnosis
External morphology of adult (Fig. 87) Moser (1918) described Holotrichia borneensis from Borneo (Sarawak) without specifying the number of specimens studied. Matsumoto (2005) transferred this species to the genus Pentelia (Brenske 1891). The first author of present paper has studied a syntype male of H. borneensis (MFNB), which is designated herein as lectotype of M. borneensis, just in case new syntype specimens are found in the future.

Diagnosis
External morphology of adult (Fig. 88) Parameres and phallobase joined by a pentagon-shaped membrane. Endophallus (Fig. 16) with two spines at middle of sac and an area more sclerotized with soft sensillae. Apophysis of temones fused dorsally; distal ends extend laterally surrounding endophallus totally, form V-shaped plate in ventral position (Fig. 16). Female genitalia with plates of gonopore fold widened caudally (Fig. 17).

Diagnosis
External morphology of adult (Fig. 90) . 18) with notch of dorsal branch well developed and circular-shaped. Endophallus (Fig. 19) with an area of soft sensillae at distal half. Apophysis of temones ( Fig. 19) separated from each other at both ends. Female genitalia unknown.

Diagnosis
External morphology of adult (Fig. 91). Body size 11.7-13.3 mm. Dorsal surface glabrous, at most with short setae in each puncture hardly visible. Male antennal club as long as funiculus. Clypeus shorter than frons, almost flat, arcuate laterally, anterior edge emarginate at middle; surface with conspicuous and deep punctures. Frons with punctures similar to those of clypeus; frontal carina blunt and curved backward. Pronotal surface with strong and deep punctures, wrinkled appearance; anterior margin glabrous, widely flanged; posterior margin with a row of punctures and very short pubescence; lateral margins widely serrated and with short setae, elevated at anterior half; anterior angles almost right, moderately projected forward, posterior angles obtuse almost right and marked. Prosternal process slender and sharp. Scutellum glabrous, with punctures uniformly distributed. Elytral surface shiny, with punctures evenly distributed and softer than those of pronotum; epipleuron glabrous, with a few short setae at basal part. Foretibia with dorsal carina moderately developed. Meso-and metatibia with transverse carina complete and interrupted respectively, inner margin of dorsal surface with a few spines. Prepygidium with punctures regularly distributed, stronger at posterior margin. Pygidium with punctures irregularly distributed glabrous, at most with tiny setae in each puncture hardly visible; apex with sparse and short pubescence. Ventrites 1 and 2 with conspicuous decumbent short pubescence regularly distributed. Ventrites 3 and 4 glabrous. Ventrite 5 moderately depressed at posterior half, with a row of long setae. Ventrite 6 with strong and deep punctures, appearance wrinkled, moderately bulging at anterior margin, long pubescence near posterior margin. Male genitalia fits into morphotype VII "Rugaticollis" above described. Parameres (Fig. 92) with notch of dorsal branch moderately developed, only a small concavity at distal end. Ventral branches slightly longer than dorsal one and with apices moderately raised. Endophallus (Fig. 93) with an area of soft setae at distal half. Apophysis of temones (Fig. 93) separated from each other at both ends. Female genitalia not studied.

Material examined
Lectotype ( Moser (1916) described Holotrichia nigrescens from a series of specimens from Deccan and Madurai (India). We have studied three type specimens (MFNB) (two males and another one without abdomen that could be a female), which show external and genital features that characterize the genus Miridiba and the genital morphotype VII "Rugaticollis". Hence, we transfer H. nigrescens to Miridiba and include it into this genital morphotype. Moreover, we designate lectotype and paralectotypes.

Species included in Morphotype VIII "Scutata"
The group is composed of two species, which are characterized by antenna 10-segmented, pronotal surface irregularly and scattered punctate (distance between punctures greater than diameter of puncture) and male and female genitalia as specified above. (Reitter, 1902) comb. nov. 94 Holotrichia scutata Reitter, 1902

Diagnosis
External morphology of adult (Fig. 94) . 20) with dorsal and ventral branches joined laterally. Dorsal branches fused with apex asymmetrical, elevated and twisted. Ventral branches reduced, lightly sclerotized and fused by a ventral membrane. Endophallus (Fig. 21) with a raspula with soft setae and spines at distal end; with spines isolated at middle. Apophysis of temones (Fig. 21) long and separated from each other. Female genitalia (Fig. 22) as described above (morphotype VIII "Scutata").

Remarks
Nonfried (1892) cited Holotrichia scutata Reitter, 1892 collected in Nienghali (Guangxi province of China), mentioning a publication, which, supposedly, contained the original species description. Unfortunately, we have not found this paper. Reitter (1902) described this species from Hong Kong without specifying the origin or number of specimens described. Later, Moser (1909), ignoring the existence of Brenske's species and Reitter's description, published another taxon named Holotrichia scutata Moser, 1909, also from Hong Kong. Soon after, Dalla Torre (1912) realized the primary homonymy and proposed the name Holotrichia scutulata for H. scutata of Moser (1909). We have studied one type specimen of H. scutata Reitter, 1902 (MFNB), which shows external features that characterize the genus Miridiba. Hence, we transfer H. scutata Reitter, 1902 to Miridiba and establish the genital morphotype VIII "Scutata". Besides, we have studied a type specimen of Holotrichia scutulata Dalla Torre, 1912 (MFNB), verifying the similarities of external morphology and male genitalia (parameres shape, sclerotized structures and sensillae in the endophallus) between both taxa, which confirm the synonymy Figs 94-97. 94. Miridiba scutata (Reitter, 1902)   described Miridiba lassallei based on a male specimen. According to the original description and illustrations (Keith 2010: figs 9-11), the characteristic shape of aedeagus, its asymmetry, the fusion and twist of dorsal branches, and fusion of ventral ones, distinguish it from other known Miridiba species. Nevertheless, after studying the holotype of M. lassallei (DKC), we have noted that the features of the external morphology and male genitalia that characterize M. scutata (Reitter, 1902) are also present in M. lassallei. Therefore, we established the synonymy of M. lassallei with M. scutata.

Distribution
China (Guangxi, Hongkong), Vietnam (Nghia Lo).  Figs 95   described Miridiba schoolmeesteri based on a male holotype from Vietnam. After studying the holotype (DKC), we consider that features of external morphology and genitalia confirm that this species belongs to Miridiba. Although the aedeagus is damaged, the parameres seem to have one dorsal and two ventral branches, the ventral ones partially fused, and endophallus with raspulae at distal end and spines isolated at middle, similar to that of M. scutata. These characteristics could suggest that M. schoolmeesteri belongs to morphotype VIII "Scutata". Hence, we include M. schoolmeesteri in the morphotype VIII.

Distribution
Vietnam.

Diagnosis
External morphology of adult (Fig. 98). Dorsal surface glabrous and densely punctate. Clypeus with anterior edge widely emarginate at middle and oblique laterally. Frontal carina developed and sharp. Anterior pronotal margin flanged, with a concavity moderately developed at each lateral end; posterior margin glabrous; lateral margins smooth, elevated laterally at anterior third; anterior angle acute; posterior angle obtuse and rounded. Scutellum densely punctate. Elytral surface with punctures more scattered than those on pronotum; epipleuron with long yellow setae along all its length. Foretibia with dorsal carina moderately developed. Meso-and metatibia with transverse carina interrupted at middle; inner margin of metatibial dorsal surface with two strong spines. Pygidium dense punctate and conspicuously pubescent; apex with long pubescence. Ventrites punctate and conspicuously pubescent. Ventrite 2 with short pubescence decumbent. Ventrites 3 and 4 with scattered pubescence at middle. Ventrite 5 with long pubescence on posterior half, irregularly distributed. Ventrite 6 with long pubescence along posterior margin. Male genitalia: parameres ( Fig. 23) with dorsal branches of dorsal tubular complex sharp apically and with a tendency to converge (Fig. 23A), apices of ventral branches of dorsal tubular complex convergent (Fig. 23B) and curved ventrally (Fig. 23C); in lateral view, dorsal and ventral branches of dorsal tubular complex forming a semi-circular concavity (Fig. 23C). Ventral branches reduced. Phallobase longer than parameres. Endophallus, temones and female genitalia not studied.
Other material VIETNAM • 1 ♂, 1 ♀; Frey det.; MFNB. Moser (1913b) described Holotrichia ciliatipennis without indicating how many species he studied. Frey (1970) transferred this species to Neodontocnema Arrow, 1948 and illustrated the parameres only in dorsal view. The first author of the present paper has examined four specimens of H. ciliatipennis (MFNB) (3 males and 1 female, including two types), which show external and genital features that characterize Miridiba. However, male genitalia show features not shared with species belonging to other genital morphotypes of Miridiba. Hence, we transfer H. ciliatipennis to Miridiba and describe the male genitalia morphotype IX "Ciliatipennis" based on this species. Moreover, we designate lectotype and paralectotype.  described Miridiba siamensis from only one male specimen. Unfortunately, we were unable to study the holotype. However, according to the original description, this species shows features of the external morphology that characterize the genus Miridiba, such as labrum strongly depressed at middle, frons with developed carina, foretibia with a row of longitudinal pubescence and apices of first-four segments of fore-and mesotarsi with a tuft of setae ventrally. On the other hand, the author illustrated the male genitalia in lateral and dorsal views (Keith 2004: figs 2-3). According to the illustrations   fig. 2), the parameres in lateral view could have the dorsal tubular complex characteristic of morphotype IX. The upper part shows divergent branches in dorsal view   fig. 3), and the lower part shows short ventral branches pubescent with apical ends curved ventrally (Keith 2004: fig. 2). Besides, dorsal tubular complex forms a soft concavity, typical of this genital morphotype at distal end. Unfortunately,  did not illustrate the parameres in ventral view, and it is not possible to tell whether the ventral branches under the dorsal tubular complex are present, or not. In our opinion, the morphology of the parameres shows features that characterize the genital morphotype IX "Ciliatipennis". Hence, we consider Miridiba siamensis should be included in this genital morphotype. Nevertheless, the holotype must be studied to confirm this consideration.

Diagnosis
See Gao et al. (2018). Gao et al. (2018) described Miridiba xingkei based on the male holotype and thirteen paratypes (4 males and 9 females) conserved in IZCAS and NWAFU of China. This species shows features that characterize genital morphotype IX "Ciliatipennis". The parameres have the characteristic dorsal tubular complex : figs 3g-i) with dorsal and ventral branches (upper and lower parts) (Gao et al. 2018: fig. 3h) forked at distal end : fig. 3g), showing in lateral view the distinctive concavity at distal end : fig. 3h). On the other hand, the ventral branches appear reduced but obvious, fused laterally to dorsal tubular complex forming an apparent lateral scar : figs 3h-i). According to these features, we include M. xingkei in the genital morphotype IX "Ciliatipennis".

Remarks
Unfortunately, we were unable to study any type specimens of this species. The first author of this paper has examined all specimens in IZCAS collection illustrated and identified as M. aequabilis by Chang (1964), concluding that these specimens are M. frontalis and not M. aequabilis. The original description (Bates 1891) showed that species is bearing strong, sharp frontal carina and 9-segmented antennae with 3 lamellae, which have significant similarities with those of L. sinensis and L. castanea. Therefore, this species is confirmed to belong to Miridiba. Nevertheless, it is necessary to study types of M. aequabilis to confirm the assertion and to include it in a genital morphotype.

Diagnosis
External morphology of adult (Fig. 99). Antenna 10-segmented. Dorsal surface glabrous, densely punctate. Clypeus shorter than frons, with conspicuous punctures, oblique laterally, anterior edge strongly emarginate at middle. Frons with punctures similar to those of clypeus; strong frontal carina. Pronotal surface densely punctate (distance between punctures smaller than diameter of puncture); anterior pronotal margin glabrous, regularly flanged; posterior margin glabrous; lateral margins smooth, moderately elevated at anterior half; anterior angles sharp and not projected forward, posterior angles obtuse and rounded. Prosternal process with two-pointed ends. Scutellum densely punctate, glabrous. Elytral surface glabrous and punctate, without striations defined, epipleuron with short pubescence on basal half. Foretibia with strong dorsal carina. Meso-and metatibia with transverse carina interrupted, and inner margin of dorsal surface with sharp spines. Pygidium glabrous, with deep punctures irregularly distributed, apex with short pubescence. Ventrites 1 and 2 densely punctate, with conspicuous decumbent pubescence regularly distributed. Ventrites 3 and 4 with a transversal row of short and robust pubescence arranged at middle of sternites. Ventrite 5 with strong punctures and long pubescence irregularly distributed on posterior half. Ventrite 6 concave moderately bulging anteriorly, punctures unevenly distributed and with long pubescence on posterior margin. Female unknown.

Remarks
According to the original descriptions (Keith 2020), this species shows features that characterize Miridiba on head (punctures, frontal carina, labrum); legs (longitudinal carina of foretibia; tufts of first four tarsomeres) and genitalia (parameres with branches). Unfortunately, we were unable to study the types and the male genitalia illustrated by Keith (2020) does not allow us to assign this species to any genital morphotype. Therefore, M. enigmatica is considered as species incertae sedis within the genus Miridiba.

Distribution
Vietnam. Gao & Fang, 2019 Miridiba ( , which would justify considering this new species in the subgenus. We have studied herein M. sinensis that, together with M. pseudosinensis, M. axanensis and M. quasisinensis, constitute the morphotype V "Sinensis", candidate to be subgenus Pledina (see Discussion and Conclusions), and we have not found enough similarities to consider M. lamellata belonging to morphotype V "Sinensis". The antenna 10-segmented, the only character considered by Gao et al. (2019) to classify this new species in the subgenus Pledina, is shared by many other Miridiba species, those included herein in morphotypes II to VIII, and even by many other species of Holotrichia. Therefore, this character is not enough to consider M. lamellata belonging to Pledina.

Miridiba lamellata
In addition to that, this new species can be separated from M. sinensis by the branches of parameres and setae on mentum and pygidium (Gao et al. 2019: figs 9, 14-17), both species are so different that M. lamellata cannot be considered belonging to Pledina. Likewise, the mentum and labrum of M. lamellata differ from those of Miridiba. Unlike Miridiba, the new species has the mentum with sparse pubescence on the anterior part, and the labrum more strongly depressed at its ventral part than at dorsal one (Gao et al. 2019: figs 5, 9). Therefore, the second author of this paper has doubts about inclusion of M. lamellata in the genus Miridiba. However, taking into account that the first author of this paper is one of the authors of the species and the second author has not studied it, M. lamellata is considered a species incertae sedis of Miridiba.
Features of parameres provide characters at specific and higher taxonomic rank. In Miridiba, the shape of parameres is variable among genital morphotypical groups. There is a trend on parameres with four branches well-defined in the Trichophora group (I), to branches almost completely fused as in Scutata and Ciliatipennis groups (VIII and IX). As the other six morphotypical groups, the dorsal branches are well-defined but fused at proximal end in the Gressitti and Leucophthalma groups (II and III); the dorsal branches are completely or almost completely fused, forming an unique dorsal branch with a dorsal scar in the Bidentata and Rugaticollis groups (IV and VII); the dorsal and ventral branches are completely or partially fused laterally in the Sinensis group (V); and the ventral branches are fused at proximal end to form a tubular structures in the Borneensis group (VI). The epithelium of endophallus is covered with sensilla dense to a greater or lesser extent, spines in different shapes and position. The internal sensilla can be related to premating recognition of partner, and spines could anchor the endophallus in female genital chamber during mating. All internal structures mentioned above within endophallus correspond to species taxonomic rank and can apply to species identification. The anchorage point of the endophallus is usually located at the distal ends of temones, but in M. thai and M. youweii the endophallus is joined to temones at middle between proximal and distal ends. In most Miridiba species, temones are at the dorsal position, thickened to a greater or lesser extent at distal ends. However, occasionally, the distal ends can extend laterally surrounding the endophallus partially or completely until joined ventrally. In the last case, the ends are joined completely and the ventral structure could be homologous to V-shaped plate described by Sanmartín & Martín-Piera (2003) in Pachydeminae Reitter, 1902. Accordingly, the strong development of temones, the presence of armed apical membrane and the endophallus insertion point are distinguishable to M. thai and M. youweii from the other species of morphotype I. The lateral extension of distal ends of temones, partially surrounding the endophallus, is distinguishable to M. bidentata, M. saigonensis and M. waterstradti from the other species of morphotype IV and surrounding completely the endophallus is distinguishable to M. coxalis and possibly M. borneensis (morphotype VI), from the other Miridiba species. Therefore, the characters of temones are diagnostic to supra-specific taxonomic rank.
Female genitalia of Miridiba are studied and described herein in detail for the first time. The anal fold allows the rectum to project backwards as well as discharging faeces. The gonopore fold fits the opening and closing of gonopore and its approach to the vulva together with the sensory structures (Fig. 1). The function of gonopore are: 1) laying the eggs from the median oviduct; 2) to facilitate, through sensory styli and plates, the courtship and female choice, opening or closing the gonopore according to receptivity of the female and 3) folds, sternites and tergites keep the genital chamber and gonopore open in copulation. The genital chamber plays active roles in sexual selection by female choice in Melolonthinae (Eberhard 1992(Eberhard , 1993. The sclerotized degree of median oviduct and the shape and size of sensory structures of genital chamber are diagnostic in supra-specific taxonomic rank. The shape and length of spermatheca and spermathecal gland are variable among Miridiba species.
We establish nine genital morphotypes, which distinguish nine Miridiba species groups. Among all genital morphotypes, the most controversial is morphotype V "Sinensis". Its distinctive male and female genital features could support the subgeneric status of Pledina. Nevertheless, a phylogenetic approach is necessary to test the monophyly of species groups and the phylogenetic relationships among them and Miridiba species. Only in this way, it will be possible to establish reliable taxonomic categories and verify the reality of Pledina and its taxonomic rank based on phylogenetic inference.