Miridiba waterstradti ( Moser, 1912 )

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 : 62-64

Miridiba waterstradti ( Moser, 1912)

Figs 79–82

Holotrichia waterstradti Moser, 1912: 441 (type loc.: Brunei).

Miridiba waterstradti – Matsumoto 2011: 3, figs 3, 14 (combination).

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 ( Moser, 1912) Chuan-bu Gao & Coca-Abia det. 2017”; MFNB.

Paralectotypes (here indicated) BRUNEI • 1 ♀; “N. Borneo Brunei Waterstradt S.”; “ Holotrichia waterstradti Type ♀ Mos”; “SYNTYPE Holotrichia waterstradti Moser 1912 labelled by MFNB 2017 ”; “♀”; “Paralectotype Miridiba waterstradti ( Moser, 1912) Chuan-bu Gao & Coca-Abia det. 2017”; MFNB • 1 ♀; “N. Borneo Brunei Waterstradt S.”; “SYNTYPE Holotrichia waterstradti Moser 1912 labelled by MFNB 2017 ”; “Paralectotype Miridiba waterstradti ( Moser, 1912) Chuan-bu Gao & Coca-Abia det. 2017”; MFNB • 1 ♀; “ Waterstradti Mos.”; “N. Borneo Brunei Waterstradt S.”; “SYNTYPE Holotrichia waterstradti Moser 1912 labelled by MFNB 2017 ”; “Paralectotype Miridiba waterstradti ( Moser, 1912) Chuan-bu Gao & Coca-Abia det. 2017”; MFNB.

Remarks

Moser (1912) 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.

Distribution

Borneo ( Brunei, Mt Bawang).

Species included in Morphotype V “Sinensis”

The group is composed of four species, which are characterized by antenna 10-segmented, pronotal surface densely punctate (distance between punctures smaller than diameter of puncture), pronotal lateral margins glabrous and smooth except at middle where is moderately serrated with short pubescence, and male and female genitalia as specified above.

Figures

Figs 79–82. Miridiba waterstradti (Moser, 1912). 79–81. Lectotype, ♂ (MFNB). 79. Habitus in dorsal view. 80. Parameres in dorsal (A), ventral (B) and lateral (C) views. 81. Endophallus and temones in dorsal view. 82. Paralectotype, ♀ (MFNB), genitalia in dorsal view. Scale bars: 79 = 5.0 mm; 80–82 = 1.0 mm.