Eumenes longus Nguyen

Nguyen, Lien Thi Phuong, 2016, Two new species of the genus Eumenes Latreille, 1802 (Hymenoptera: Vespidae, Eumeninae) from Vietnam, Zootaxa 4093 (4), pp. 583-588 : 583-585

Eumenes longus Nguyen , sp. nov. ( Figs 1–6 )

Material examined. Holotype, ♀, “ VIETNAM, Bac Giang, Khe Dan, Tuan Dao, Son Dong, 4.vii.2010, DD Tran [IEBR]. Paratypes: VIETNAM: Bac Giang: 1 ♂, Thanh Son, Son Dong, 120 m, 5.vii.2010, PH Pham [IEBR].

Description. Female. Body length 13 mm; fore wing length 10.3 mm. Head in frontal view subcircular, 1.2 × as wide as high ( Fig. 1 ). Distance from posterior ocelli to apical margin of vertex as long as distance from posterior ocelli to inner eye margin. Gena in lateral view 0.5 × as wide as eye. Occipital carina complete. Distance between inner eye margins (frontal view) at vertex 1.8 × more than at clypeus. Clypeus in lateral view gradually convex from base to apical margin; in frontal view much higher than wide, 1.6 × as high as wide ( Fig. 1 ), with basal margin slightly concave medially and distinctly separated from antennal sockets; apical margin deeply emarginate medially, rounded by lateral tooth ( Fig. 1 ); width of emargination 0.5–1.0 × of clypeus width between inner eye margins. Mandible with prominent teeth, fourth tooth long and pointed apically. Scape 3.5 × as long as its maximum width; F1 3.3 × as long as its maximum width, F2 1.4 × as long as wide, F3–F6 slightly longer than wide, F7 as long as wide, F8–F9 wider than long, F10 bulletshaped, 1.2 × as long as its basal width.

Mesosoma slightly longer than its width in dorsal view. Pronotal carina absent dorsally, present laterally, slightly raised and touching pronotal ventral corner. Mesoscutum convex, as long as wide between tegulae; anterior margin broadly rounded. Disc of scutellum convex. Disc of metanotum flat. Propodeal groove distinct from base to apex, without fovea.

Metasomal segment 1 long and slender ( Fig. 2 ), nearly 1.4 × longer than mesosoma length, T1 4 × as long as wide, slightly depressed along tergum, in dorsal view basally widened, then parallel to apical margin ( Fig. 3 ), with maximum width about 2 × its basal width, tergum and sternum fused, leaving suture between them distinct throughout the segment. T 2 in lateral view slightly gibbous, slightly constricted near apical margin, with base swollen dorsally ( Fig. 2 ), in dorsoposterial view pear shaped, in lateral view 1.1 × as long as wide, with well developed apical lamella, with transverse sulcus at middle near apical margin. S 2 in lateral view nearly straight.

Body covered with short, silver setae except temple and mesosoma with longer setae. Clypeus with deep and sparse punctures each bearing a silver seta, minute punctures in between them, space between punctures usually larger than puncture diameter. Mandible with several shallow small punctures. Frons densely covered with deep large punctures, space between punctures smooth. Vertex and gena with sparse, deep, and well-defined punctures, interspaces between punctures smooth. Pronotum with coarse, flat-bottomed punctures, spaces between punctures narrow, strongly raised to form reticulation. Mesocutum with dense and coarse flat-bottomed punctures, interspaces raised to form reticulation, border between punctures near lateral sides and apical margin with some minute punctures. Punctures on scutellum coarser than those near lateral margin of mesoscutum. Punctures on metanotum coarse, border between them weakly defined. Mesepisternum with large and coarse punctures posterodorsally as in scutellum, barely punctured anteroventrally; border between posterodorsal and anteroventral parts distinct. Metapleuron latero-dorsally with week short striae, laterally with some weakly defined shallow punctures Propodeum with punctures on dorsal surface similar to those on scutellum, punctures on lateral parts smaller and shallower than in dorsal part. T1 covered with large and deep punctures, with interspace larger than puncture diameter at lateral parts, with minute punctures in between them; punctures on T2 larger and deeper than punctures on T1, border between punctures raised to form reticulation similar to those on scutellum, punctures near lateral sides and apical margin small and sparser, minute punctures in between them; T3–6 with minute punctures; punctures on S2 small, shallow and sparse.

Color. Black. The following parts yellow: narrow band along inner eye margin extending from bottom of frons to ocular sinus, a spot between antennal sockets transversal divided at the middle, a large spot at basal margin of clypeus, short line at vertex behind eye, band at basal margin and spot at apical corner (close to tegula) of pronotum, narrow short band at lateral margin of mesoscutum, spot on apical margin of tergula, parategula, spot on dorsal and ventral mesepisternum, fain mark on scutellum, transverse line on metanotum longitudinal divided at the middle (anterior and posterior margin black), spot on dorsal and posterial part of propodeum, apical band on T1 and T2 (divided into 3 segment on T2), spot on lateral side of T2, outer side of fore and mid- tibia (a short band on mid-tibia), spot on fore femora at apex. Last antennal flagellomere beneath ferruginous. Legs black. Propodeal valvulae dark brown. Wings dark brown, strongly infuscate, veins dark brown.

Male. Body length 12 mm; fore wing length 9.7 mm. Structure as in female, but differing as follows: Distance from posterior ocelli to apical margin of the vertex slightly greater than the distance from posterior ocelli to inner eye margin. Distance between inner eye margins (frontal view) at vertex 2.2 × more than at clypeus. Clypeus in frontal view 2 × as high as wide, apical margin deeply emarginate medially, forming blunt round tooth on each lateral side ( Fig. 4 ), width of emargination nearly 1/2 width of clypeus between inner eye margins. Mandible with four distinct teeth on inner side, basal tooth long and point apically. Antennal scape 3.3 × as long as its maximum width; F1 3 × as long as its maximum width, F2 1.7 × longer than wide, F3–6 longer than wide, F7–8 as long as wide, F9 wider than long, F10 small, as long as wide, F11 slightly curve, sharply point apically, the apex received at F8 near apical margin, slightly less than 2.5 × as long as its basal width ( Fig. 5 ).

Color. Similar to female but yellow spot on clypeus larger and extending from base to nearly apical margin, tegula and scutellum completely black, yellow band on metanotum much reduced, yellow spot on propodeum and yellow band at apical margin of T1 reduced, yellow spot on lateral side and band at apical margin of T2 absent.

Distribution. Vietnam: Bac Giang, Nghe An.

Remarks. This species can be distinguished from congeners by the combination of the following characters: clypeus 1.6 × as high as wide, metasomal segment 1 4 × as long as wide, nearly 1.4 × as long as mesosoma, metasomal segment 2 gibbous, base of T2 forming with the sternum an acute angle.

Etymology. The specific name refers to the length of the metasomal segment 1.

Figures

FIGURES 1 – 6. Eumenes longus sp. nov., 1 – 3: holotype, ♀. 1. Head, frontal view. 2. Metasomal segments 1 - 2, lateral view. 3. T 1, dorsal view. 4 – 6: ♂. 4. Head, frontal view. 5. Right antenna. 6. Habitus.