Coeleumenes, van der Vecht, 1963

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 : 195-196

Key to all species of the genus Coeleumenes occurring in the Oriental region

The characters are applicable to both sexes unless the sex is specified. The characters are taken from descriptions of the species following Sonan (1939), Giordani Soika (1935, 1941), and van der Vecht (1963) except C. burmanicus ( Bingham, 1897) and C. flavus Nguyen, 2016 from Vietnam, which were examined directly.

We note that the description of C. thoracicus ( Sonan, 1939) and its figure is very similar to C. burmanicus ( Bingham, 1897) (only slightly different were the punctures on the dorsal face of the propodeum), but the type of C. thoracicus has not yet been checked, so the status of this species is left as it is.

1. Head and mesosoma with coarse punctures, border between punctures raised and forming reticulation. Propodeum without apical teeth at lateral sides, without translucent acarinarium. Sternum I with strong striae. Body mostly black, with few yellow markings............................................................................................ 2

- Head and mesosoma with less coarse punctures, border between punctures smooth. Propodeum with more or less developed apical teeth at lateral sides, with somewhat swollen translucent acarinarium. Sternum I with weaker striae. Body with more extensive yellow markings.............................................................................. 3

2. Dorsal face of propodeum with very dense coarse punctures, border between punctures raised and forming reticulation.............................................................................. C. burmanicus ( Bingham, 1897)

- Dorsal face of propodeum with dense minute punctures................................ C. thoracicus ( Sonan, 1939)

3. Tergum II without, or with narrow hardly raised, apical lamella...............................................….4

- Tergum II with thicker apical lamella, slightly or strongly raised................................................ 7

4. Tergum I without produced node laterally...................................................................5

- Tergum I with produced node laterally......................................................................6

5. Clypeus shallowly emarginate anteriorly, with apical teeth blunt. Lateral surface of propodeum and metasomal petiole with fine punctures. Tergum II with apical margin lamella wider. Female clypeus with a broad yellow band at base; mesoscutum with four short yellow lines; tergum I black with a narrow yellow apical band; legs black with yellow markings....................................................................................... C. timorensis van der Vecht, 1963

- Clypeus deeper emarginate anteriorly, with apical teeth sharper. Lateral surface of propodeum and metasomal petiole with stronger punctures. Tergum II with apical margin lamella narrower. Female clypeus with four yellow spots; mesoscutum with two yellow short lines; legs and basal half of tergum I ferruginous................. C. multicolor ( Giordani Soika, 1935)

6. Tergum I narrow at base and abrupt expended to apical margin, its width half as wide as tergum II. Mandible black with apex red, spot at base yellow; pronotum entirely black; legs black with tarsi slightly ferruginous; wings brown with purple reflection................................................................... C. indianus (de Saussure, 1855)

- Tergum I gradually expanded from base to apical margin, its width less than half as wide as tergum II. Mandible entirely black; pronotum black with yellow line at anterior margin, interrupted in the middle; legs testaceous red, with black on femora; wings fusco-hyaline............................................................. C. rufipetiolatus ( Wickwar, 1908)

7. Tergum II with apical margin slightly raised................................................................ 8

- Tergum II with apical margin strongly raised............................................................... 10

8. Tergum II with apical margin wider. The puncturation stronger. Metasomal petiole relatively longer. Terga I-II with more or less narrow yellow apical bands.......................................................... C. vindex ( Smith, 1859)

- Tergum II with apical margin narrower. The puncturation much finer. Metasomal petiole relatively shorter. Terga I-III with wide yellow apical bands................................................................................... 9

9. Female clypeus with apical margin deeper emarginate. Puncturation of propodeum and metasomal petiole less coarse and less dense. Propodeum with distinct translucent area at apex. Mandible black, antennal scape reddish yellow in front, legs largely red; colour of yellow markings darker........................................... C. secundus ( Dalla Torre, 1889)

- Female clypeus with apical margin shallowly emarginate. Puncturation of propodeum and metasomal petiole coarser and denser. Propodeum without distinct translucent area at apex. Mandible largely, antennal scape and legs largely bright red; colour of yellow markings distinctly paler.............................................. C. ruficrus van der Vecht, 1963

10. Tergum I without produced node laterally.......................................... C. imparidus ( Bingham, 1897)

- Tergum I with produced node laterally.................................................................... 11

11. Body with find punctures. Propodeum with translucent, bluntly square expansion laterally. Tergum I with weak produced node laterally, slightly greater than 2.5 times as long as wide in dorsal view. Sternum II gradually convex in lateral view. Body black with less yellow marks............................................................... C. chumomray sp. nov.

- Body with well-defined punctures. Propodeum with translucent, bluntly round expansion laterally. Tergum I with strong produced node laterally, about twice as long as wide in dorsal view. Sternum II strongly convex in lateral view. Body black with extensive yellow marks.......................................................... C. flavus Nguyen, 2016