Orancistrocerus altus, Truong & Bozdoğan & Nguyen, 2019

Truong, Lam Xuan, Bozdoğan, Hakan & Nguyen, Lien Thi Phuong, 2019, Taxonomic studies on the genus Orancistrocerus van der Vecht, 1963 (Hymenoptera: Vespidae: Eumeninae) from Vietnam, with description of a new species, Zootaxa 4563 (3), pp. 595-599 : 596-598

Orancistrocerus altus sp. nov.

( Figs 3–9 )

Material examined. Holotype, ♀, labeled “ VIETNAM, Lan Chau, Huu Lien NR, Huu Lien , Lang Son, 21°43'22.9"N, 106°22'40.2"E, ca 370 m, 12 June 2018, coll. L.T.P. Nguyen ” [ IEBR] . Paratype: VIETNAM: [ IEBR]: 1 ♀, Lan Nghe, Huu Lien NR, Huu Lien , Lang Son, 21°33'48.6"N, 106°24'36.4"E, ca 289 m, 11 June 2018, coll. L.T.P. Nguyen, T.V. Luong, N.T. Tran, L.X. Truong.

Diagnosis. This species can be distinguished from other Orancistrocerus by the clypeus and tergum II: the clypeus in frontal view is nearly as high as wide, with the apical margin deeply emarginated, half oval shape, the width of the emargination is 0.4 times the width of the clypeus between the inner eye margins, and has an inversed U-shaped yellow mark near the basal margin; and tergum II in dorsal view is slightly wider than long, with large undefined punctures.

Description. Female. Body length 13.8–14.5 mm (holotype: 13.8 mm); fore wing length 12.2–13.1 mm (holotype: 12.2 mm). Head in frontal view subcircular, 1.3 times as wide as high ( Fig. 3 ). Vertex sloping down behind posterior ocelli towards occipital carina, with cephalic foveae small, bearing dense pubescence, situated on depressed area on vertex behind posterior ocelli, and with distance between foveae slightly greater than diameter of front ocellus. Distance from posterior ocelli to apical margin of vertex 2.4 times distance from posterior ocelli to inner eye margin ( Fig. 4 ). Gena in lateral view 0.7 times as wide as eye. Occipital carina complete, present along entire length of gena, widened at lateral part. Inner eye margins in frontal view 1.2 times further apart from each other at vertex than at clypeus. Clypeus in lateral view slightly convex basally and apically, straight medially; in frontal view nearly as high as wide ( Fig. 3 ), apical margin deeply emarginate, half-oval shaped, width of emargination 0.4 times width of clypeus between inner eye margins. Mandible with prominent wide teeth, fourth tooth blunt apically. Antennal scape long, 3.7 times as long as its maximum width; flagellomeres I 2 times as long as wide, flagellomere II 1.1 times as long as wide, flagellomeres III–IX wider than long, last flagellomere bullet shape, as long as its basal width.

Mesosoma slightly longer than wide in dorsal view. Pronotal carina present, produced at humeral angle, reaching ventral corner of pronotum. Mesoscutum convex, 0.8 times as long as wide between tegulae; anterior margin broadly rounded. Disc of scutellum slightly convex, with middle carina present at basal two-thirds. Metanotum round. Propodeum ( Fig. 6 ) strongly excavated medially, with posterior surface distinctly concave, basal triangular area with a basal fovea, at lower end median carina running to apical margin; border between dorsal and lateral surfaces rounded, posterior and lateral surfaces angled.

Metasomal tergum I in dorsal view narrower than tergum II, truncate at base ( Fig. 7 ); anterior vertical surface of tergum I slightly convex, with sparse shallow punctures, clearly separated from posterior horizontal surface by carina; posterior horizontal surface of tergum I in lateral view slightly convex dorsally; tergum I laterally divided by sharp carina into upper and lower parts. Tergum I in dorsal view 1.8 times as wide as long; tergum II in dorsal view slightly wider than long ( Fig. 7 ); sternum II in lateral view ( Fig. 8 ) slightly depressed basally, then gradually and slightly convex to apical margin.

Body with short, sparse silver setae except lower part of propodeum with longer and denser setae. Clypeus with shallow large undefined punctures on disc, border between punctures raised to form week longitudinal striations, laterally with smaller and deeper punctures. Mandible with a row of punctures laterally. Frons with dense deep and large flat-bottomed punctures, interspaces strongly raised to form reticulation; vertex and gena with smaller and weaker punctures, interspaces not raised. Pronotum with coarser punctures than frons, spaces between punctures raised to form reticulations. Mesoscutum with dense strong flat-bottomed punctures, space between punctures raised to form longitudinal striations, the striations stronger at apical margin. Scutellum punctures similar to those on pronotum. Metanotum punctures coarse and dense. Mesepisternum punctures larger coarser posterodorsally than pronotum, some small and shallow punctures anteroventrally near border between posterodorsal and anteroventral, margins indistinct. Metapleuron with few strong striae and large deep hole at upper part of dorsal area, with sparse shallow small punctures in ventral area. Propodeum with coarse and large flat-bottomed punctures dorsally, laterally punctures shallower smaller sparser, posteriorly shiny, with punctures at upper part and oblique weak carina at lower part. Tergum I with moderate punctures, clearly separated, tergum II punctures shallower undefined, punctures near apical margins of tergum II deeper, larger and coarser than those on other part of the tergum, tergum III–V punctures strong and deep, smaller than tergum II, tergum VI punctures minute; sternum II punctures deeper and larger than lateral tergum II margins, sternum III–V punctures smaller and shallower than sternum II; sternum I narrow basal part smooth.

Color. Black; following parts yellow: inverse U-shaped mark near basal margin of clypeus, two separate small spots between antennae, large spot on mandible basally, spot on tegula, band (incised medially) on apical margin of terga II and III; and the following parts ferruginous: antennal scape beneath, spot on tegula, inner side of fore femur and tibia, dorsal side of middle and hind femur. Propodeal valvulae dark brown. Wings brown, transparent, veins dark brown ( Fig. 5 ).

Distribution. Vietnam (northern provinces).

Etymology. From the Latin altus , “high”, in reference to the deep apical margin of the clypeus.

Remark. This species comes close to O. aterrimus nigriceps but differs from the later by the shape of clypeus in the female, with its apical margin deeply emarginated (slightly emarginated in O. aterrimus nigriceps ) and tergum II in dorsal view scarcely wider than long (it is about 1.2 times wider than long in O. aterrimus nigriceps ).

Figures

FIGURES 3–9. Orancistrocerus altus sp. nov., ♀, holotype. 3. Head, frontal view. 4. Vertex, dorsal view. 5. Fore wing. 6. Propodeum, dorsal view. 7. T1–2, dorsal view. 8. Metasoma, lateral view. 9. Habitus.