Miridiba coxalis ( Arrow, 1944 ) CH. Bu Gao & M. Coca-Abia, 2021

Gao, Chuan-bu & Coca-Abia, María Milagro, 2021, Revision of the genus Miridiba Reitter, 1902 (Coleoptera, Scarabaeidae, Melolonthinae): genital morphotypes and new taxonomic data, European Journal of Taxonomy 749, pp. 1-94 : 70-71

Miridiba coxalis ( Arrow, 1944) comb. nov.

Figs 16–17 , 88–89

Holotrichia coxalis Arrow, 1944: 637 (type loc.: Sarawak, Malaysia).

Pentelia coxalis – Matsumoto 2005: 483, figs 4, 9, 11, 16, 24, 27, 35, 41 (combination).

Diagnosis

External morphology of adult ( Fig. 88 ). Body size 22.0– 19.8 mm. Dorsal surface glabrous. Clypeus as long as frons, rounded laterally, with conspicuous punctures, anterior edge strongly emarginate at middle. Frons with punctures more scattered than those of clypeus; carina moderately developed but sharp. Anterior pronotal margin glabrous, regularly flanged; posterior margin glabrous, with a row of punctures; lateral margins moderately serrated and with short pubescence; anterior angles almost right and moderately projected forward, posterior angles obtuse and rounded. Prosternal process rectangular with posterior margin moderately depressed. Scutellum scattered punctate and glabrous. Elytral surface glabrous, at most with a tiny seta on each puncture hardly visible, with striations weakly defined, punctures distributed between striations. Foretibia with dorsal carina moderately developed. Meso- and metatibia with transverse carina interrupted, inner margin of dorsal surface without spines. Pygidium with strong punctures irregularly distributed; surface glabrous, at most with a tiny seta on each puncture hardly visible, apical margin pubescent. Ventrites with short whitish scales. Ventrites 1 and 2 densely punctate; ventrite 3 and 4 more scattered punctate; ventrite 5 with strong punctures and long pubescence irregularly distributed at posterior half; ventrite 6 concave moderately bulging at anterior part, punctures irregularly distributed and long pubescence on posterior margin. Male genitalia: parameres ( Fig. 89 ) Dorsal branches wavy-shaped in lateral view; with margins serrated at distal half and apices divergent in dorsal view. Ventral branches stronger than dorsal ones; moderately depressed at distal third in lateral view, apices strong and curved downward; both branches joined to each other in ventral view, apices free, separate from each other and narrowed caudally. Dorsal and ventral branches joined by a membrane. 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 ).

Material examined

Lectotype (here designated) MALAYSIA • ♂; “Quop, W. Sarawak G. E. Bryant 14.3.14 ” [Quop and Sarawak rivers 14 Mar. 1914]; “ G. Bryant Coll. 1919-147”; “Type”; “Asis”; “ Holotrichia coxalis Arrow Type”; “Lectotype Miridiba coxalis ( Arrow, 1944) CH. Bu Gao & M. Coca-Abia det. 2017”; BMNH.

Paralectotypes (here indicated) MALAYSIA • 1 ♂; “Quop, W. Sarawak G. E. Bryant 11.IV.14 ” [11 Apr. 1914]; “♂”; “ G. Bryant Coll. 1919-147”; “paralectotype Miridiba coxalis ( Arrow, 1944) CH. Bu Gao & M. Coca-Abia det. 2017”; BMNH • 1 ♀; “ Oxford Univ. Exp, BM Hobby & A.W. Moore, BM 1933-254 ” ; “ SARAWAK, foot of Mt. Dulit, Junction of rivers Tinjar & Lejok, 4.X.1932 ” [4 Oct. 1932]; “♀”; “Paralectotype Miridiba coxalis ( Arrow, 1944) CH. Bu Gao & M. Coca-Abia det. 2017”; BMNH .

Remarks

Arrow (1944) described Holotrichia coxalis from six specimens. Matsumoto (2005) transferred this species to the genus Pentelia without designating a lectotype. We have studied three syntypes (two males and one female) of H. coxalis (BMNH) . They share features of external morphology with the genus Miridiba . Moreover, the male genitalia shows characteristic of morphotype VI “ Borneensis ”. Hence, this species is included in this genital morphotype. The three syntypes of M. coxalis (BMNH) are designated as lectotype and paralectotypes.

Distribution

Malaysia ( Sarawak).

Species included in Morphotype VII “Rugaticollis”

The group is composed of two species, which are characterized by a dark reddish brown to black colour, antenna 10-segmented, male antennal club, at least, as long as funiculus; pronotal surface with coarse punctures densely distributed (distance between punctures equal or smaller than diameter of puncture); ventrite 1 visible; genital features as specified above in genital morphotype VII “ Rugaticollis ”.

Figures

Figs 15–17. Morphotype VI “Borneensis”. 15. Parameres of M. borneensis (Moser, 1918), lectotype (BMNH) in dorsal (A) and lateral (B) views. 16. Endophallus and temones of M. coxalis (Arrow, 1944), lectotype (BMNH) in dorsal view. 17. Female genitalia of M. coxalis, paralectotype (BMNH) in dorsal (A) and ventral (B) views. Scale bars = 1.0 mm.

Figs 87–89. 87. Miridiba borneensis (Moser, 1918), lectotype, ♂ (MFNB). Habitus in dorsal view. 88–89. M. coxalis (Arrow, 1944), lectotype, ♂ (BMNH). 88. Habitus in dorsal view. 89. Parameres in dorsal (A), ventral (B) and lateral (C) views. Scale bars: 87–88 = 5.0 mm; 89 = 1.0 mm.