Miridiba (Miridiba) apicespinosa 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 : 332-334

Miridiba (Miridiba) apicespinosa P.V. Pham & Keith , new species urn:lsid:zoobank.org:act:F2742890-8E0B-40B1-8E51-A149908501DB

( Figs 1 , 4a–c )

Type material. Holotype: male ( IEBR), VIETNAM: Son La Province, Thuan Chau District, Copia Nature Reserve , light trap, 28.iv.2016, Hoang Vu Tru leg. Paratypes: 1 male ( IEBR), the same data as holotype ; 2 females ( IEBR), the same locality as holotype, light trap, 01.v.2016, Hoang Vu Tru leg ; 1 female ( IEBR), the same locality as holotype, UV light trap, 15.v.2017, Pham Van Phu leg ; 1 female ( NMBS), LAOS NE: Houa Phan prov., 20°13'09N – 103°59'53- 140°00'03E, 1480-1550 m, Phou Pane Mt , 09-16. VI.2009, David Hauck leg , NHMB Basel NMPC Prague Laos 2009 expedition M. Brancucci, M. Geiser, Z. Kraus, D. Hauck, V. Kubáň ; 3 males ( NMPC), LAO-NE, Hua Phan prov., 20°12'N 104°01'E, Phu Phan Mt, 1500-1900 m, 17. V, Vit Kubáň , - 3. VI.2017; 14 males, 9 females ( NMPC), Laos NE, Houa Phan prov., 20°13'09N – 103°59'54''- 140°00'03''E, 1480-1510 m, Phou Pane Mt , 22.IV-14. V.2008, Vit Kubáň leg.

Description of the holotype (male). Body length: 16.5 mm (from anterior margin of clypeus to apex of elytra); body width: 8.6 mm (width across humeri). Color dark reddish brown on head, pronotum, scutellum; reddish brown to dark reddish brown on elytra, ventral surface, and legs; moderately shiny; body densely puncate, covered with hair-like setae ( Fig. 1a ).

Head. Surface densely punctate; punctures moderately large, each bearing a semierect seta; clypeus transverse, with apex moderately bilobed and strongly reflexed, slightly narrowing at base, length five times greater than width ( Fig. 1b ). Clypeofrontal suture clearly defined, weakly sinuated. Frontal carina clearly defined, slightly irregular, reaching periocular margins. Basal area of head with small punctures, sparser punctate than forehead ( Fig. 1b ). Antenna with 9 antennomeres, antennal club composed of 3 antennomeres, club slightly longer than antennomeres 2–6 combined ( Fig. 1e ). Last segment of maxillary palp elongated, moderately flattened.

Pronotum. Transverse; widest at basal third; pronotum with anterior margin moderately concave at lateral ends, basolateral angles obtuse and round; anterior half of lateral margin coarsely serrated, moderately reflexed, posterior half of lateral margin finely serrate, lateral margin with long sparse erect setae; anterior margin completely beaded, with long sparse erect setae ( Fig. 1b ); basal margin smooth and flat; pubescence distinctly long; setiferous punctures as large as those on head, densely set, some confluent.

Scutellum. Scutellum triangular, flat; punctures smaller than those on pronotum; lateral margins smooth, without punctures; 1.75 times wider than long; with some erect moderately long setae near apex ( Fig. 1d ).

Elytra. Discal surface densely rugose-punctate, moderately and long pubescent; widest at apical one third. Epipleuron with marginal pubescence.

Legs. Protibiae tridentate, teeth equidistant, slightly sharp, basal tooth small, middle and apical teeth mostly equal; internal apical spur inserted in front of middle tooth, reaching middle of protarsomere 1; dorsal carina of protibia reaching the apex of apical tooth, and with a branch reaching the apex of second tooth ( Fig. 1g ). Profemora, mesofemora and metafemora moderately covered with hair-like, long setae; metafemora slightly broadened anteriorly and posteriorly, slightly convex. Metatibiae with two apical spurs, nearly equal; upper spur reaching base of second tarsomere ( Fig. 1f ).

Ventral surface. Meso- and metasternum with dense, fine punctures and yellowish hair ( Fig. 1c ). Abdomen: punctures at middle finer and sparser than laterally; covered with setiferous, short setae.

Pygidium. Slightly convex, triangular, side margins bordered, apical margin thickened; dorsal surface covered with long and short setae; punctures not clear as those on elytra ( Fig. 1h ).

Aedeagus. Parameres symmetric ( Figs 4a–c ), including four braches (two dorsal and two thin ventral branches), separated in dorsal, ventral, and lateral views; dorsal braches longer than ventral ones, their apex with one ventral spine for each; ventral branches apex sharp and curved outward.

Variability. The male paratypes are almost identical to the holotype.

Female. Darker and bigger than males (body length 18.4–18.6 mm; body width 9.0– 9.2 mm). Antennomeres of club 0.65x to 0.75x shorter than in males. Upper spurs of metatibiae longer than basal second metatarsomere.

Remarks. Miridiba apicespinosa , new species shares with M. taoi Li & Wang, 2015 pubescence on pronotum, elytra and scutellum distinctly long, and pronotum with anterior margin concave at lateral ends. However, it can be easily separated from M. taoi , endemic to the small island of Lanyu off Taiwan and known only up to now by the 3 typical males, by: pronotum widest at basal third ( Fig. 1b ) (widest at middle in M. taoi ); metatibial upper spur reaching base of second tarsomere in male ( Fig. 1f ) (reaching basal one-third of second tarsomere in M. taoi ). Parameres: apex of dorsal branches with ventral spines (without such spines in M. taoi ), and ventral branches long and reaching dorsal ones (short and not reaching dorsal ones in M. taoi ) ( Figs 4a–c ). The morphological characters of M. apicespinosa , new species match the features of the morphotype “ Trichophora ” ( Fig. 1 ), thus we classify the new species as a member of this morphotype in the nominal subgenus Miridiba .

Etymology. This species is named after the ventral spines on apex of dorsal branches of parameres.

Distribution. Laos (Houa Phan) and Vietnam (Son La Province).

Figures

FIGURE 1. Miridiba apicespinosa P.V.Pham & Keith, new species.a, habitus; b, pronotum andhead; c, meso- and metasternum; d, scutellum; e, antenna; f, hindtibia; g, foretibia; h, 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.