Pseumenes furvus Nguyen, 2020

Lien, Nguyen Thi Phuong, Ngat, Tran Thi & Minh, Hoang Gia, 2020, Taxonomic noteson thegenusPseumenes Giordani Soika, 1935 (Hymenoptera: Vespidae Eumeninae) from Vietnam with key to all known species in the Oriental region, Zootaxa 4822 (2), pp. 293-299 : 294-296

Pseumenes furvus Nguyen , sp. nov.

( Figs 1–8 )

Material examined. Holotype, female, pinned (deposited in IEBR), labeled “ VIETNAM: Cao Duong, Yen Thuan, Ham Yen , Tuyen Quang, Cham Chu NP, 22°17′08.6″N 104°59′27.4″E, 17.v. 2019, 691 m, Nguyen T. P. Lien, Truong X. Lam, Tran T. Ngat & Mai V. Thai”.

Diagnosis. This species can be distinguished from other species of the genus Pseumenes by the following combination of characters: Head in frontal view slightly wider than high; body with coarse punctures; clypeus in lateral view gradually convex from base to near apical margin, then slightly bend back ward, in frontal view higher than wide; mesoscutum higher than wide; metasomal tergum I long and slender, in dorsal view nearly 2.5 times as long as wide, tergum II in lateral view gradually convex from base to apical margin, without lamella apically; propodeum with lateral side shallowly emarginated at apex, border between dorsal and lateral faces bluntly angle; body almost black except an irregular mark at the middle base of clypeus, large spot between antennal sockets and antennal scape beneath yellow.

Description. Female ( Fig. 8 ). Holotype: Body length 15.1mm; fore wing length 14.9 mm. Head in frontal view subcircular, slightly wider than high, about 1.05 times as wide as high ( Fig.1 ). Ocelli placed in a slightly raised triangle, the posterior pair slightly far apart as from the eyes, the anterior ocellus slightly larger than the posterior ocellus. Vertex without fovea, area behind the ocellus triangle prominently swollen. Distance from posterior ocelli to apical margin of vertex about 2.5 times distance from posterior ocelli to inner eye margin ( Fig. 2 ). Gena in lateral view 1.1times as wide as eye at ocular sinus, sharply tapering in the lower third. Occipital carina presents only at lateral sides, evanescent dorsally. Inner eye margins convergent ventrally, in frontal view 1.27 times as far from each other at vertex as at clypeus. Clypeus with a small flattened area just above apical margin, disc of clypeus in lateral view gradually convex from base to near apical margin, then slightly bend back ward, in frontal view 1.18 times as high as wide ( Fig. 1 ), with basal margin slightly convex medially and almost touching antennal sockets; apical margin emarginate medially, forming blunt tooth on each lateral side ( Fig. 1 ), width of emargination much less than 1/4 width of clypeus between inner eye margins. Mandible broad, rather short, with prominent five teeth, the first, second and fourth teeth from base triangular shape, the third one truncated, the apical one pointed. Antennal scape long, about 4.5 times as long as its maximum width; flagellomere I 2.0 times as long as wide, flagellomeres II–IX slightly longer than wide, terminal flagellomere bullet shape, longer than wide.

Mesosoma longer than wide in dorsal view ( Fig. 2 ). Pronotal carina strongly raised through out, reaching ventral corner of pronotum. Mesoscutum in lateral view strongly convex ( Fig. 3 ), in dorsal view longer than wide, 1.12 times as long as wide between tegulae, without any trace of prescutal furrows near apical margin, the lateral impressed longitudinal lines near lateral sides also indistinct ( Fig. 2 ). Disc of scutellum slightly concave, in lateral view at the same level of apical margin of mesoscutum ( Fig. 3 ). Metanotum slightly convex, sloping down to apical margin. Propodeum short and broad dorsally, moderately convex, deeply excavated medially, with the excavation wide, about one-third the width of propodeum, the excavation with edges raised in the form of two parallel and sharp carinae, basal triangular area with longitudinal basal fovea, with median carina runs from fovea to apical margin ( Fig. 4 ), several obliquely ribbed flank on both sides of the median carina, lateral side shallowly emarginate at apex; border between dorsal and lateral faces bluntly angle.

Metasomal tergum I long and slender, in dorsal view nearly 2.5 times as long as wide, lateral tubercles inconspicuous and not visible, with a short longitudinal furrow apically ( Fig. 5 ), in lateral view gradually convex from base, then slightly depress and gradually convex to near apical margin ( Fig. 7 ), much narrower than tergum II; tergum II in dorsal view slightly longer than wide, in lateral view gradually convex from base to apical margin, without raised lamellae at apical margin; sternum II in lateral view gradually and slightly convex from base to apical margin ( Fig.7 ).

Body covered with golden setae. Head and most of mesosoma with short setae, the setae longer on scutellum, metanotum, propodeum, and metasomal petiole. Clypeus covered with coarse and dense punctures, each bearing a medium length seta, punctures at center larger than at sides, area between punctures with micro punctures, punctures near apical margin smaller but denser. Mandible with a row of medium punctures along inner side of teeth, and several shallow small punctures. Frons densely covered with coarse punctures. Vertex with less coarse punctures than in frons, punctures on gena smaller and sparser than on vertex and with space between puncture smooth. Pronotum with punctures similar to those on frons, anterior face smooth. Mesoscutum densely covered with strong and flat-bottomed punctures except small smooth areas along impressed longitudinal lines, punctures at apical margins sparser and less coarse. Punctures on scutellum similar to those near apical margin of mesoscutum. Punctures on metanotum smaller than those on scutellum, indistinct. Mesepisternum with punctures on upper dorsal part very coarse, space between punctures strongly raised to form reticulation, with strong and large punctures posterodorsally, several shallow and small punctures anteroventrally; border between posterodorsal and anteroventral parts indistinct. Metapleuron largely smooth, dorsal part with several long strong striae, and ventral part with several short strong striae, with some shallow and very sparse punctures. Propodeum with coarse and dense punctures on each side of the excavated area except in a small smooth area on each side medially, lateral surface obliquely rugose, with several shallow punctures in between rugose area. Tegulae with sparse and small punctures. Metasomal tergum I covered with medium punctures, punctures rather dense, punctures at lateral sides of tergum II similar but sparser than those on tergum I, punctures at dorsal part fainter, punctures on terga III–VI much smaller and weaker than those on tergum II; terga V–VI with minute punctures; sternum I narrowed and parallel in the basal two-thirds, enlarged rather abruptly in the apical third with several indistinct and short transverse striae in the middle of the narrowed basal region, the remaining surface without striate, with strong punctures; punctures on sterna II and III very sparse, punctures on sterna IV and V much denser than those on sterna II–III, sternum VI with minute punctures.

Color. Black; following parts yellow: an irregular mark at the middle base of clypeus, large spot between antennal sockets and narrowly extending to the anterior ocellus, antennal scape beneath. Flagellomeres beneath ferruginous. Propodeal valvulae brown. Legs black. Wings infuscate, veins dark brown.

Male. Unknown.

Distribution. Vietnam (Northern part).

Etymology. The specific name refers to the black color of the body.

Remarks. This species comes close to Pseumenes imperatrix ( Smith, 1857) in keys, but can be distinguished from the later by having head in frontal view slightly wider than long (slightly higher than wide in P. imperatrix ), ocelli placed in a slightly convex triangle (ocelli placed in a very flat triangle in P. imperatrix ), mesoscutum longer than wide between tegulae (slightly wider than long in P. imperatrix ), tegulae with sparse and small punctures (tegulae smooth in P. imperatrix ), tergum II in lateral view slightly convex (tergum II in lateral view strongly convex in P. imperatrix ); and coloration: body almost entirely black (more extensive yellow in P. imperatrix ).

Figures

FIGURES 1–8. Pseumenes furvus, newspecies, holotype, female.1, Head in frontal view. 2, Mesosoma in dorsal view. 3, Mesosoma in lateral view. 4, Propodeum in posterior view. 5, Tergum I in dorsal view. 6, Metasomal terga II–V in dorsal view. 7, Metasomal segments in lateral view. 8, Habitus. Scale: 1mm.