Eustenogaster Saito & Kojima, 2007, sp. nov.
Creators: name: Saito, Fuki
name: Kojima, Jun-Ichi
Publisher: name: Zenodo
Year: 2007
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hymenoptera
Vespidae
Eustenogaster

description: Key to species of Eustenogaster
This key may, in most respects, reflect no phylogenetic relationships among the species. Neither specimen nor character description in the literature was available to us for the females of E. luzonensis (Rohwer, 1919), and the male of E. fumipennis Saito, sp. nov. and E. eximia (Bingham, 1890).
1. Female; antenna with ten flagellomeres; metasoma six-segmented............................................................ 2
- Male; antenna with 11 flagellomeres; metasoma seven-segmented.......................................................... 15
2. Lateral furrow of pronotum deep (Fig. 8).................................................................................................... 3
-. Lateral furrow of pronotum shallow or absent (Figs. 23, 44)...................................................................... 4
3. Lateral furrow of pronotum reaching humeral tubercle (Fig. 8). Scutellum and propodeum entirely black, or black with small, yellow spots .................................................................... fulvipennis (Cameron, 1902)
-. Lateral fullow of pronotum not reaching humeral tubercle. Scutellum with paired, yellow spot; propodeum with longitudinal, yellow band (sometimes interrupted) on each lateral side ..... agilis (Smith, 1860)
4. Lateral sides of pronotum and dorsal part of mesepisternum dull, densely and sometimes rugosely punctate; puncture larger than interspace between punctures. Second metasomal tergum in lateral view distinctly convex dorsally (Figs. 11, 17, 19).............................................................5 [fraterna species group]
- Lateral sides of pronotum and dorsal part of mesepisternum finely punctate; some interspaces between punctures larger than puncture. Second metasomal tergum in lateral view only slightly convex dorsally (Figs. 24, 33, 40, 56).................................................................................................................................... 7
5. First tergum in dorsal view barely widened in some distance behind level of spiracles, then widened in posterior one-fifth of the tergum (Fig. 10); second tergum weakly convex dorsally (Fig. 11). Clypeus yellow except for broad apical band and lateral margins black; frons with large, yellow spot below each antennal socket (Fig. 57); mesepisternum with two yellow spots; base of second tergum with paired yellow spots nearly coalescent .................................................................................. fraterna (Bingham, 1897)
- First tergum in dorsal view gradually widened posteriorly from level of spiracles (Fig. 15); second tergum strongly convex dorsally (Figs. 17, 19). Clypeus entirely black or with median, yellow spot; supraclypeal area and base of second tergum black ......................................................................................................... 6
6. Clypeus (Fig. 57) and propodeum entirely black, with yellow spots absent. nigra Saito and Nguyen, 2006
- Clypeus usually with yellow spot of variable size (Fig. 57), rarely entirely black; propodeum with paired apical yellow spots .................................................................................................. scitula (Bingham, 1897)
7. Space between antennal sockets with rather sparse, shallow punctures; interspace between punctures larger than puncture. Scutum with sparse, shallow punctures; interspace between punctures usually larger than puncture .......................................................................................................... eximia (Bingham, 1890)
- Space between antennal sockets densely, and sometimes rugosely, punctate; interspace between punctures smaller than puncture. Scutum densely covered with well-defined punctures; interspace between punctures mostly smaller than puncture .............................................................................................................. 8
8. Frons clearly demarcated from clypeus by suture (Fig. 41) ................................. latebricola Saito, sp. nov.
- Frons barely demarcated from clypeus........................................................................................................ 9
9. Supraclypeal area just above clypeus with dense, well-defined punctures; interspace between punctures
smaller than puncture................................................................................................................................. 10 - Supraclypeal area just above clypeus with sparse, shallow punctures; interspace between punctures larger than puncture ............................................................................................................................................. 11
10. Extreme apex of clypeus sharply pointed (Fig. 35). Gena black; pronotal neck with paired yellow spots [absent in specimens from Vietnam]; first metasomal tergum with paired posterolateral yellow spots ....... .......................................................................................................................... hauxwellii (Bingham, 1894)
- Extreme apex of clypeus truncate (Fig. 21). Gena yellow marked; pronotal neck and first tergum with yellow spots absent .................................................................. calyptodoma (Sakagami and Yoshikawa, 1968)
11. Median impunctate area in supraclypeal area much larger than anterior ocellus. Second metasomal tergum with distinct transverse impression [sometimes weak in specimens from Mentawai Is.] separating somewhat swollen posterior two-fifths from anterior part (Fig. 33) ......... gibbosa Starr and van der Vecht, 2006
- Median impunctate area in supraclypeal area smaller than anterior ocelli. Second metasomal tergum with transverse impression absent (Fig. 56) ...................................................................................................... 12
12. Area below each antennal socket covered with long, dense hairs. Scutum with large, sparse punctures; interspace between punctures usually larger than puncture, especially in anterior part of scutum........... 13
- Area below each antennal socket covered with short hairs. Scutum with small, dense punctures; interspace between punctures smaller than puncture.................................................................................................. 14
13. Space between antennal sockets rugosely punctate. Clypeus extensively marked with yellow (Fig. 58). Metapleuron, metanotum, metasomal segments with yellow spots or marks ...... spinicauda Saito, sp. nov.
- Space between antennal sockets with dense, fine punctures. Clypeus black except for small lateral yellow spots (Fig. 57). Metapleuron, metanotum, metasomal segments entirely black............................................ .............................................................................................................................. fumipennis Saito, sp. nov.
14. Eye emargination marked with yellow (Fig. 58). Narrow yellow band in each posterodorsal corner of pronotum reaching tegula ................................................................................. micans (de Saussure, 1852)
- Eye emargination black (Fig. 58). Narrow yellow band in each posterodorsal corner of pronotum ending before tegula ............................................................................................................ palavanica Reyes, 1988
15. Mandible with three teeth (Figs. 5, 13)...................................................................................................... 16
- Mandible single-toothed (Fig. 25) ............................................................................................................. 19
16. Mandible appearing single-toothed, with median tooth reduced into slight convexity; proximal tooth reduced in size (Fig. 5) .................................................................................................. agilis (Smith, 1860)
- All three mandibular teeth more or less distinct, apically blunt (Fig. 13)..........17 [fraterna species group]
17. Second tergum in profile weakly convex dorsally (Fig. 14). Supraclypeal area with paired yellow spots (Fig. 57) ................................................................................................................ fraterna (Bingham, 1897)
- Second tergum in profile strongly convex dorsally (Figs. 18, 20). Supraclypeal area with yellow spots absent ......................................................................................................................................................... 18
18. Second tergum in lateral view strongly swollen dorsally in anterior half (Fig. 18). Clypeus (Fig. 57) and propodeum entirely black .............................................................................. nigra Saito and Nguyen, 2006
- Second tergum less strongly convex dorsally (Fig. 20). Clypeus usually with a median yellow spot of variable size (Fig. 57), rarely entirely black; propodeum as a rule with paired apical yellow spots................... ................................................................................................................................ scitula (Bingham, 1897)
19. Lateral furrow of pronotum deep, distinctly striate reaching humeral tubercle (Fig. 8). Clypeal apex with median impunctate ridge (Fig. 7) ..................................................................... fulvipennis (Cameron, 1902)
- Lateral furrow of pronotum shallow or absent. Clypeal apex medially convex or flattened, with ridge absent (Figs. 46, 55)................................................................................................................................... 20
20. Clypeus in lateral view flattened dorsally, smoothly passing into supraclypeal area (Fig. 36). Digitus without median spine and apically with dense, long hairs (Fig. 59 T) ..................... hauxwellii (Bingham, 1894)
- Clypeus in lateral view weakly convex dorsally (Figs. 47, 51), separated from supraclypeal area by shal-
low depression or short suture. Digitus with median spine and apically with short hairs (Fig. 59 V)....... 21 21. Clypeus separated from supraclypeal area by short suture (Fig. 46). Ventral margins of penis valve with prominent serrations extending apically toward apical swollen part of aedeagus (Fig. 48) ......................... .............................................................................................................................. latebricola Saito, sp. nov. - Clypeus separated from supraclypeal area by shallow depression. Ventral margins of penis valve with serrations restricted to proximal part or minute if extending towards apical swollen part of aedeagus ........ 22
22. Median impunctate area in supraclypeal area large, as large as or larger than anterior ocellus (sometimes slightly smaller than anterior ocellus in E. micans)................................................................................... 23
- Median impunctate area in supraclypeal area small, somewhat smaller than anterior ocellus ................. 25
23. Second metasomal tergum with transverse impression, separating somewhat swollen posterior two-fifths from anterior part. Supraclypeal area medially without hairs and impunctate.............................................. .......................................................................................................... gibbosa Starr and van der Vecht, 2006
- Second metasomal tergum without such impression, in lateral view regularly curved dorsally. Supraclypeal area finely punctate and covered with short hairs.............................................................................. 24
24. Area around ocelli with dense, fine punctures. Eye emargination filled with yellow................................... ........................................................................................................................... micans (de Saussure, 1852)
- Area around ocelli with larger punctures; interspaces between punctures often smaller than puncture diameters. Eye emargination with small yellow spot or black (Fig. 58) ................. palavanica Reyes, 1988
25. Pronotum dorsolaterally with deep furrows behind pronotal collar (Fig. 23). Punctures on scutum fine and dense, with their interspaces smaller than their diameter. Gena ventrally with large, yellow spot............... ............................................................................................ calyptodoma (Sakagami and Yoshikawa, 1968)
- Pronotum without such furrows. Punctures on scutum large and dense; in anterior part of scutum interspace between punctures sometimes larger than puncture. Gena entirely black ....................................... 26
26. Head with yellow spot above each antennal socket and paired yellow spots on vertex present (Fig. 58) .... .............................................................................................................................. spinicauda Saito, sp. nov.
- Head with yellow spots above antennal socket and on vertex, all absent (Fig. 58) ...................................... ............................................................................................................................ luzonensis (Rohwer, 1919)
description: Published as part of Saito, Fuki & Kojima, Jun-Ichi, 2007, A taxonomic revision of the hover wasp genus Eustenogaster van der Vecht (Insecta: Hymenoptera; Vespidae, Stenogastrinae), pp. 1-30 in Zootaxa 1556 on pages 6-8, DOI: 10.5281/zenodo.178242