Coeleumenes chumomray Mai and Nguyen, 2021

Mai, Thai Van & Nguyen, Lien Thi Phuong, 2021, New findings on the taxonomy of the genus Coeleumenes van der Vecht (Hymenoptera: Vespidae: Eumeninae) from Vietnam, with description of a new species, Zootaxa 4969 (1), pp. 191-196 : 192-195

Coeleumenes chumomray Mai and Nguyen , sp. nov.

( Figs. 1–9 )

Diagnosis. This species can be distinguished from all other known species of the genus Coeleumenes by the following combination of characters: body shiny, with fine and sparse punctures; propodeum with dorsal face convex, on each side with a remarkable translucent, bluntly square expansion, with an oval opening laterally; tergum I in dorsal view slightly tuberculate laterally at midpoint; tergum II with strongly raised apical lamella; sternum I with weak transverse striae; sternum II gradually convex from base to apical margin; and color pattern.

Material examined. HOLOTYPE, ♂, pinned (deposited in IEBR), “ VIETNAM, Kon Tum, Sa Thay , Chu Mom Ray NP, 19°4724.5N, 104°59′46.5″E, alt. 729 m, 25.iv.2016, Nguyen Thi Phuong Lien & Tran Thi Ngat” . Paratypes (deposited in IEBR): 4 ♂, same data as holotype .

Description. Male ( Fig. 10 ). Body length 11.0– 11.2 mm (holotype: 11.1 mm); forewing length 9.0– 9.2 mm (holotype: 9.0 mm). Head in frontal view subcircular, about 1.18 times as wide as high ( Fig. 1 ). Vertex without cephalic fovea. Distance from posterior ocelli to apical margin of the vertex nearly three times the distance from posterior ocelli to inner eye margin ( Fig. 2 ). Gena narrow, about 0.6 times as wide as eye (at end of ocular sinus); occipital carina developed only laterally. Inner eye margins strongly convergent ventrally; in frontal view 1.3 times further apart from each other at vertex than at clypeus. Clypeus in lateral view gradually convex from base to basal half, then nearly straight to apical margin; in frontal view slightly higher than wide ( Fig. 1 ), with basal margin slightly convex and almost touching antennal sockets; apical margin strongly emarginated medially, forming a sharp tooth on each side ( Fig. 1 ); width of the emargination much greater than ⅓ width of clypeus between inner eye margin (0.4 times width of clypeus between inner eye margin). Mandible with four distinct teeth, first tooth with inner side sharply emarginated medially and forming two large triangle shape. Antennal scape, about 4.3 times as long as its maximum width, curved; flagellomere I 2.2 times as long as its maximum width, flagellomeres II–VII longer than its width, flagellomeres VIII–IX wider than long, flagellomere X small, as long as wide, flagellomere XI slightly curve, 2.6 times as long as its basal width ( Fig. 3 ).

Mesosoma dorsally longer than its width ( Fig. 4 ). Pronotal carina raised, slightly produced at humeral angles ( Fig. 5 ), reaching ventral corner of pronotum. Mesoscutum weakly convex, much shorter than its width, 0.77 times as long as wide; anterior margin broadly rounded. Disc of scutellum weakly convex, in lateral view at the same level as mesoscutum ( Fig. 5 ), strongly depressed along anterior margin laterally. Metanotum almost flat. Propodeum ( Fig. 6 ) without shelf, posterior surface excavated near apical margin, with deep median groove, a medial carina at apical half, border between posterior and lateral surfaces angled.

Metasomal segment I subpetiolate, longer than segment II. Tergum I dorsally nearly 2.6 times along as wide, with tubercle at lateral half ( Fig. 7 ), with a short medium depression near apical margin, less than twice as wide as tergum II (1.75 times as wide as tergum II); tergum II slightly wider than long, 1.07 times as wide as long ( Fig. 8 ), with apical lamella thick and strongly raised; sternum II in lateral view gradually convex from base to apical margin ( Fig. 9 ).

Body shiny, with long, silver setae, with fine and sparse punctures. Clypeus with fine and sparse punctures, space between punctures greater than 3 to 4 times puncture diameters, almost flat in the middle. Mandible with several shallow small punctures. Frons with sparse and shallow punctures, vertex and gena with deeper and clearly defined punctures. Pronotum with larger and coarser punctures than punctures on vertex. Mesocutum finely and sparsely punctate, punctures on scutellum and metanotum sparser than punctures on mesoscutum. Tegula sparsely punctate at base and apex, remainder micropunctate. Mesepisternum with epicnemial carina, with some big holes dorsally, with punctures posterodorsally similar to those on mesoscutum, barely punctured anteroventrally; border between posterodorsal and anteroventral parts distinct. Metapleuron almost smooth. Propodeal posterior face with sparse and large punctures and with small punctures in between them; with strong striae laterally. Terga I and II with fine and sparse punctures except deeper and larger punctures near apical margins, terga III– VII with minute punctures; punctures on sternum II smaller than those on tergum II, sternum I with transverse striae throughout sternum, apical part with weaker striae, with narrow basal parts smooth.

Color. Black and shining; following parts yellow: clypeus except apical margin, basal spot on mandible, large crown shaped spot between antennae which extend to front, thick band along inner eye margin and running to ocular sinus, thick band at vertex behind eye, frontal part of scape, thick band along pronotal carina at dorsal part of pronotum (narrowly broken medially), sometimes two spots on scutellum (in one paratype), two spots on metanotum, a line along the margin of the translucent expansions (omitted at inner side), spot on apex of tegulae, parategulae, sometimes a spot at dorsal mesepisternum (in one paratype), a narrow band at apical margin of tergum I, a thick band (broken laterally) at apical margin of tergum II, sometimes this band not broken (in two paratypes), sometimes a narrow short line at apical margin of tergum III medially, and lateral spot at corner of sternum II, sometimes also lateral spot at corner of sternum III (in two paratypes). Legs black, apical one-third of fore femur, outer side of fore and middle tibia, and apical spot of middle tibia yellow; dorsal part of middle and hind femurs, ventral part of fore and middle tibiae, ventral part of hind tibia apically and tarsi of all legs brown.

Remarks. This species is morphologically similar to Coeleumenes multicolor ( Giordani Soika, 1935) in having the propodeum on each side with a remarkable translucent expansion, the mandible with a yellow spot, the scutellum black, the tegulae black with a yellow spot at the apex, and the propodeum with a yellow line along the margin of the translucent expansions, but it can be easily distinguished from the latter by the bluntly square expansion (bluntly rounded expansion in C. multicolor ), an oval opening laterally (approximately circular opening laterally in C. multicolor ), and metasomal segment I black except a narrow yellow band apically (basal half of metasomal segment I red in C. multicolor ).

This species also close to Coleumenes flavus Nguyen, 2016 in having the propodeum on each side with a remarkable translucent expansion and extensive yellow markingd, but compared to C. flavus , the new species has much weaker body punctures, the propodeum with the expansion apically more developed with the translucent portion larger, the tubercle on the lateral side of tergum I less produced, tergum I with the proportion between length and maximum width longer, sternum II less convex laterally; and overall fewer yellow markings.

Symbiotic associations with mites (family Winterschmidtiidae (Acari)) were observed in Coeleumenes burmanicus from Vietnam ( Nguyen, 2016) and now are also found in one paratype of C. chumomray , sp. nov. ( Fig. 11 ).

Female. Unknown.

Distribution. Vietnam (Tay Nguyen highland).

Etymology. The specific name refers to the name of the Chu Mom Ray National Park, where the species was collected; it is to be treated as a noun in apposition.

Figures

FIGURES 1–6. Coeleumenes chumomray sp. nov., holotype, male, 1. Head, frontal view; 2. Head, dorsal view; 3. Left antenna; 4. Mesosoma, dorsal view; 5. Mesosoma, lateral view; 6. Propodeum, posterior view. Scale bar: 1 mm.

FIGURES 7–11. 7–10. Coeleumenes chumomray sp. nov., holotype male: 7. Metasomal tergum I, dorsal view; 8. Metasomal terga II–VII, dorsal view; 9. Metasomal segments, lateral view; 10. Habitus; 11. Paratype: lateral side of propodeum, symbiotic associations with mites. Scale bar: 1 mm.