Miridiba (Miridiba) quangnamensis P.V. Pham & Keith, 2022

Pham, Phu Van, Keith, Denis, Pham, Nhi Thi & Cao, Nga Quynh Thi, 2022, Threenew species ofthe genus MiridibaReitter, 1902 (Scarabaeidae: Melolonthinae) from Vietnam along with a new country record, Zootaxa 5205 (4), pp. 331-342 : 336-337

Miridiba (Miridiba) quangnamensis P.V. Pham & Keith , new species urn:lsid:zoobank.org:act:8E9A0286-D3C8-4C19-83B2-56A4E09585A9

( Figs 3 , 4 g-i)

Type material. Holotype: male ( IEBR), Quang Nam Province, Nam Giang District, Cha Vai, Song Thanh , light trap, 28.iv. 2005, 520 m above sea level.

Description of the holotype (male): Body length: 16.3 mm (from anterior margin of clypeus to apex of elytra); body width: 7.7 mm (width across humeri). Color dark reddish brown on head, pronotum, and scutellum; yellowish brown to dark reddish brown on elytra, ventral surface, and legs; moderately shiny; dorsal surface almost glabrous ( Fig. 3a ).

Head. Surface densely punctate; punctures large; clypeus transverse, with apex moderately bilobed and reflexed, widened at base, length five times greater wide ( Fig. 3b ). Clypeofrontal suture visible, moderately sinuated. Frontal carina moderately raised, weakly curved backwards, reaching periocular margins ( Fig. 3b ). Basal area of head with punctures smaller than those on forehead, punctures with short erect setae ( Fig. 3b ). Antenna with 9 antennomeres, antennal club composed of 3 antennomeres, club longer than length of antennomeres 2–6 combined (2.5/ 1.7 mm). Last segment of maxillary palp elongated, dorsal surface with callus.

Pronotum. Transversal, widest at middle; anterolateral angles moderately protuberant; basolateral angles round; lateral margin smooth; anterior margin completely bordered; basal margin finely flanged and smooth, without pubescence; setiferous punctures smaller than those on clypeus ( Fig. 3b ).

Scutellum. Triangular, flat; strongly and densely puncate except on side margins; nearly two times wider than long ( Fig. 3d ).

Elytra. Elytra nearly parallel, slightly widened posteriorly. Punctures dense near the base, less posteriad; base of elytra bearing several long setae. Epipleura end at one fifth posteriorly bearing a row of long setae.

Legs. Protibiae tridentate, teeth equidistant, tip of teeth moderately round; basal tooth small, middle tooth two third as apical teeth; internal apical spur inserted in front of middle tooth, reaching basal one-third of protarsomere 1; dorsal carina of protibia reaching the apex of apical tooth, and with a branch reaching the apex of second tooth ( Fig. 3e ). Profemora, mesofemora, and metafemora moderately covered with hair-like, long setae; metafemora strongly broadened anteriorly, slightly convex. Metatibia with two apical spurs, upper spur moderately longer than lower spur, and reaching one fourth of mesotarsomeres 2 ( Fig. 3f ). Meso- and metatibiae with strong teeth on external margins and complete carina at apical third.

Ventral surface. Meso- and metasternum with dense fine punctures and yellowish hair ( Fig. 3c ). Abdomen: second and third visible abdomenal sternites densely covered with punctures, and long setae; those on fourth and fifth sternites sparserly punctate and setiferous, particularly on median parts; sixth sternite covered with longer setae.

Pygidium. Slightly convex, triangular, margin bordered, apical margin moderately reflexed; dorsal surface with punctures identical to those on elytra with long and erect setae ( Fig. 3f ).

Aedeagus. Curved downwards, symmetrical in lateral view, bird's beak-like, without acicular expansion at base ( Figs 4g –i ).

Female. Unknown.

Remarks. Miridiba quangnamensis , new species is closely similar to M. hanoiensis Keith, 2006 ( Figs 5d–f ) but they can be separated by the following characters combined: posterior pronotal margin without pubesence in M. quangnamensis , new species (pubescent in M. hanoienis ); clypeo-frontal suture visible in M. quangnamensis , new species (invisible in M. hanoiensis ); antenna club longer than length of antennomeres 2–6 combined in M. quangnamensis , new species ( Fig. 3d ) (almost equal in M. hanoiensis ); anterolateral angles moderately protuberant in M. quangnamensis ( Fig. 3b ) (nearly rectangular in M. hanoiensis – Fig. 5d ); median limits between sternites slightly opaque in in M. quangnamensis , new species (invisible in M. hanoiensis ), and the shape of parameres ( Figs 5e,f ; 4g –i ). The morphological characters of M. quangnamensis new species do not characterize any morphotype proposed by Gao & Coca-Abia (2021) and Gao et al. (2022), so the new species remains as incertae sedis in the genus Miridiba .

Etymology. This species is named after the locality of the holotype (Quang Nam Province).

Distribution. Vietnam (Quang Nam Province).

Figures

FIGURE 3. Miridiba quangnamensis P.V. Pham & Keith, new species. a, habitus; b, pronotum and head; c, meso- and metasternum; d, scutellum; e, foretibia; f, hindtibia; g, pygidium.

FIGURE 4. Male genitalia of Miridiba apicespinosa P.V. Pham & Keith, new species (a–c), Miridiba ngoclinhensis P.V. Pham & Keith, new species (d–f) and Miridiba quangnamensis P.V. Pham & Keith, new species (g–i). a, d, g, parameres in lateral view; b, e, h, parameres in dorsal view; c, f, i, parameres in ventral view.

FIGURE 5. Miridiba pseudosinensis Keith, 2010 (a–c) and Miridiba hanoiensis Keith, 2006 (d–f). a, d, habitus; b, e, parameres in lateral view; c, f, parameres in dorsal view. Figures 5d–f photographed by Olivier Montreuil. Not in scale.