Stenodynerus, de Saussure, 1863, de Saussure, 1863

Zeng, Xin, Chen, Bin & Li, Ting-Jing, 2024, The genus Stenodynerus de Saussure, 1863 (Hymenoptera: Vespidae: Eumeninae) from China: a new species, new records, and key to the species, Zootaxa 5514 (4), pp. 385-400 : 396-397

Key to species (female and male)

(modified from Ma et al. 2016)

1. Apical border of T 2 bent upwards almost at a right angle, forming a perpendicular lamella, and preapical portion of tergum often strongly depressed immediately preceding this lamella, creating a wide transverse groove ( Fig. 29 in Ma et al. 2016). 2

- Apical border of T 2 barely depressed, or at most obtusely bent, and preapical portion of T 2 at most narrowly impressed ( Figs 9 , 16 , 24 , 31 , 38 , 45 , 53 )................................................................................ 8

2. Anterior surface of T 1 vertical, with sparse punctures and a median longitudinal carina in upper half ( Figs 10 , 26 , 33 , 78 in Ma et al. 2016).......................................................................................... 3

- Anterior surface of T 1 not vertical and somewhat rounded, with strong punctures, and without a median longitudinal carina (in Ma et al. 2016)....................................................................................... 7

3. S2 ventrally in basal portion without a median longitudinal furrow basally ( Figs 28 , 35 in Ma et al. 2016)............... 4

- S2 ventrally in basal portion with a median longitudinal furrow basally........................................... 5

4. Interspace between two median foveae of anterior surface of pronotum much more than diameter of one fovea ( Fig. 25 in Ma et al. 2016). Anterior vertical surface of T 1 with transverse striae; both apical border of T 2 and groove at base of border obviously wide ( Fig. 29 in Ma et al. 2016).................................................... S. strigatus Ma & Li, 2016

- Interspace between two median foveae of anterior surface of pronotum almost equal to diameter of one fovea ( Fig. 32 in Ma et al. 2016). Anterior vertical surface of T 1 without transverse striae; both apical border of T 2 and groove at base of border narrower than above species ( Fig. 36 in Ma et al. 2016)........................... S. tenuilamellatus Ma & Li, 2016

5. In female, clypeus black (Fig. 77 in Ma et al. 2016). In lateral view, anterior surface of S2 sloping.................... 6

- In female, clypeus with yellow or ferruginous spots. In lateral view, anterior surface of S2 vertical ( Fig. 12 in Ma et al. 2016).......................................................................... S. reflexus Ma, Chen & Li, 2016

6. Body with yellow spots; pronotum with a pair of small spots dorsally, metanotum with a yellow band anteriorly, T 1 with a narrow apical band (Fig. 78 in Ma et al. 2016)................................. S. pappi pappi Giordani Soika, 1976

- Body with orange yellow spots; pronotum with a broad band, metanotum almost entire orange yellow, T 1 with a broader apical band............................................................ S. pappi luteifasciatus Kim & Yamane, 2004

7. In female, clypeus yellow. S2 with dense punctures; in male, both T 1– T 7 and S2–S3 with yellow apical bands........................................................................................ S. morawitzi Kurzenko, 1977

- In female, clypeus black. S2 with sparser punctures; in male, both T 1– T 2 and S2 with yellow apical bands (Figs 61, 62 in Ma et al. 2016).......................................................................... S. tergitus Kim, 1999

8. Interocellar region conically tuberculate ( Fig. 12 ); vertex depressed and sloping................................... 9

- Interocellar region normal, evenly convex to same level as ocelli ( Figs 2 , 19 , 27 , 34 , 41 , 49, 50 ); vertex not depressed.... 10

9. Propodeum medially with a transverse plane behind metanotum, well-developed ( Fig. 14 ). T 1 with dense and strong punctures ( Fig. 16 )...................................................................... S. coreanus ( Tsuneki, 1970)

- Propodeum medially without a transverse plane behind metanotum. T 1 with weaker and sparser punctures....................................................................................... S. taiwanus Kim & Yamane, 2004

10. Anterior surface of S2 vertical..................................................... S. nudus ( Morawitz, 1889)

- Anterior surface of S2 sloping ( Figs 8 , 23 , 30 , 37 , 44 , 56 ).................................................... 11

11. Propodeum medially without a transverse plane behind metanotum ( Figs 22 , 36 , 43 ).............................. 12

- Propodeum medially with a transverse plane behind metanotum ( Figs 6 , 29 , 55 ).................................. 16

12. Propodeal concavity smooth, very shiny in middle.................................. S. incurvitus Gusenleitner, 2003

- Propodeal concavity coarse, reticulate-punctate or with long and transverse rugae ( Figs 22 , 36 , 43 )................... 13

13. Pronotum with sharp and acute shoulder ( Fig. 1 in Ma et al. 2016); posterior surface of propodeum with a complete median longitudinal carina ( Fig. 4 in Ma et al. 2016)................................. S. ningliangensis Ma, Chen & Li, 2016

- Pronotum with rounded and obtuse shoulder ( Figs 18 , 33 , 40 ); posterior surface of propodeum with an incomplete median longitudinal carina ( Figs 22 , 36 , 43 )..................................................................... 14

14. T 2 and S2 with minute and sparse punctures ( Figs 37–39 )............................ S. punctifrons ( Thomson, 1874)

- T 2 and S2 with more or less coarse and denser punctures ( Figs 23–25 , 44–46 ).................................... 15

15. T 1 less than 2× as wide as long ( Figs 40, 45 ), punctures of T 2 moderately dense ( Fig. 44 ); tegula and legs largely ferruginous ( Fig. 40 )............................................................... S. steckianus (von Schulthess, 1897)

- T 1 at least 2× as wide as long ( Figs 18, 24 ); punctures of T 2 much denser ( Fig. 23 ); tegula and legs largely yellow ( Fig. 18 )............................................................................ .. S. difficilis ( Morawitz, 1867)

16. S2 ventrally in basal portion with a median longitudinal furrow ( Fig. 10 )........................................ 17

- S2 ventrally in basal portion without or just with an obsolete median longitudinal furrow ( Figs 32 , 54 )................ 25

17. Pronotal foveae forming U-shaped ( Fig. 7 ); anterior face of pronotum with parallel transverse striae above median foveae, extending lateral margin of foveae ( Fig. 7 )................................................................ 18

- Pronotal foveae forming V-shaped ( Figs 28 , 51 ); anterior face of pronotum without transverse striae above median foveae ( Figs 28 , 51 ), or at most with short and fine ones, not extending lateral margin of foveae................................ 19

18. Gena 0.90–0.95× as wide as eye at bottom of ocular sinus ( Fig. 5 ); anterior surface of pronotum almost vertical; pronotal carina well-developed in dorsal side (Fig. 69 in Ma et al. 2016)........................... S. frauenfeldi ( de Saussure, 1867)

- Gena 0.5–0.55× as wide as eye at bottom of ocular sinus ( Fig. 4 ); anterior surface of pronotum sloping ( Fig. 7 ); pronotal carina obsolete on dorsal side ( Fig. 7 )........................................ S. tongrenensis Zeng, Chen & Li , sp. nov.

19. Body with large and dense punctures, strongly sculptured ( Figs 47, 48 ); anterior surface of pronotum sloping, and with distinct and strong punctures ( Fig. 51 ).......................................................................... 20

- Body with comparatively smaller punctures, moderately sculpture; anterior surface of pronotum almost vertical, with few punctures.......................................................................................... 22

20. Clypeus in female with lateral longitudinal carina and shovel-shaped in middle (Fig. 64 in Ma et al. 2016), S2 with distinct and large punctures (Fig. 68 in Ma et al. 2016)................................ S. chinensis chinensis ( de Saussure, 1863)

- Clypeus in female just apically with obsolete longitudinal carina, not shovel-shaped in middle; S2 with shallower and smaller punctures.......................................................................................... 21

21. Clypeus with dense punctures and slightly wider apical margin than interantennal distance. T 1 almost as wide as long. Smaller species, body length generally less than or equal to 9 mm .................... S. xanthomelas ( Herrich-Schäeffer, 1839)

- Clypeus with sparser punctures and much narrower apical margin. T 1 1.25× wider than long. Larger species, body length generally more than 11 mm in both sexes...................................... S. morbillosus Giordani Soika, 1979

22. Clypeus in both sex and apical bands of T 1–5 orange-yellow; clypeus strongly punctate ( Figs 51, 53 in Ma et al. 2016)............................................................................ S. nepalensis Giordani Soika, 1985

- Clypeus in female black or just basal half orange-yellow, and at most apical bands of T 1–3 yellow; clypeus moderately punctate............................................................................................ 23

23. Clypeus in female black; T 1 and T 2 with weak punctures............................. S. copiosus Gusenleitner, 2012

- Clypeus in female with basal orange-yellow band; T 1 and T 2 with strong punctures............................... 24

24. Anterior surface of pronotum medially with wide V-shaped foveae; apex of T 2 with shallow and sparse punctures; in male, volsella slightly truncate apically ( Figs 18, 20 , 45 in Ma et al. 2016)............... S. similibaronii Ma, Chen & Li, 2016

- Anterior surface of pronotum medially with narrow V-shaped foveae; apex of T 2 with strongly deep and dense punctures; in male, volsella rounded apically ( Figs 40, 41, 44 , in Ma et al. 2016).................... S. baronii Giordani Soika, 1975

25. Anterior surface of pronotum with a few short and fine striae above median foveae (Fig. 75 in Ma et al. 2016).......... 26

- Anterior surface of pronotum without transverse striae above median foveae ( Figs 28 , 51 ).......................... 27

26. Clypeus with small shallow punctures; pronotal carina complete; in male,A11 ventrally concave,A13 flat and almost rectangular, not tapered when seen from above.............................................. S. clypeopictus ( Kostylev, 1940)

- Clypeus with larger and deeper punctures; pronotal carina interrupted medially; in male, A11 ventrally normal, not concave, A13 tapered when seen from above................................................... S. funebris ( Andrè, 1884)

27. T 2 and S2 coarsely and densely punctate ( Figs 54, 56 )....................................................... 28

- T 2 and S2 finely and sparsely punctate ( Figs 30, 31 )........................................................ 29

28. Clypeus wider than long; pronotum with sharp and acute shoulder (Fig. 66 in Gusenleitner 1981)............................................................................................ S. chevrieranus ( de Saussure, 1855)

- Clypeus as long as wide ( Figs 49, 50 ); pronotum with rounded and obtuse shoulder ( Fig. 51 ).. S. trotzinai ( Morawitz, 1895)

29. Anterior surface of pronotum largely smooth, with sparse small punctures only in lateral and lower portions; lateral face of propodeum densely striate with sparse punctures...................................... S. pullus Gusenleitner, 1981

- Anterior surface of pronotum almost with punctures; lateral face of propodeum sparsely striate with dense punctures..... 30

30. Clypeus with coarse punctures mixed with a few rugae ( Fig. 46 in Ma et al. 2016); in lateral view, S2 rounded basally............................................................................... S. bluethgeni van der Vecht, 1971

- Clypeus with sparse punctures and interspaces between punctures smooth, without rugae ( Fig. 27 ); in lateral view, S2 angled basally ( Fig. 30 )............................................................. S. kaszabi Giordani Soika, 1976

Figures

FIGURES 26–32. Stenodynerus kaszabi, ♀. 26. Habitus, dorsal view. 27. Head, frontal view. 28. Pronotum, dorsal view. 29. Propodeum, dorsal view. 30. Metasomal segments 2–6, lateral view. 31. T1–T6, dorsal view. 32. S2–S6, ventral view.

FIGURES 1–10. 1–4, 6–10. Stenodynerus tongrenensis sp. nov., holotype, ♀. 5. S. frauenfeldi, ♀. 1. Habitus, dorsal view. 2. Head, frontal view. 3. Head, dorsal view. 4, 5. Head, lateral view. 6. Propodeum, dorsal view. 7. Pronotum, frontal view. 8. Metasomal segments 2–6, lateral view. 9. T1–T6, dorsal view. 10. S2–S6, ventral view.

FIGURES 11–17. Stenodynerus coreanus, ♀. 11. Habitus, dorsal view. 12. Head, frontal view. 13. Pronotum, dorsal view. 14. Propodeum, dorsal view. 15. Metasomal segments 2–6, lateral view. 16. T1–T6, dorsal view. 17. S2–S6, ventral view.

FIGURES 18–25. Stenodynerus difficilis, ♂. 18. Habitus, dorsal view. 19. Head, frontal view. 20. Antenna. 21. Pronotum, dorsal view. 22. Propodeum, dorsal view. 23. Metasomal segments 2–6, lateral view. 24. T1–T7, dorsal view. 25. S2–S7, ventral view.

FIGURES 33–39. Stenodynerus punctifrons, ♀. 33. Habitus, dorsal view. 34. Head, frontal view. 35. Pronotum, dorsal view. 36. Propodeum, dorsal view. 37. Metasomal segments 2–6, lateral view. 38. T1–T6, dorsal view. 39. S2–S6, ventral view.

FIGURES 40–46. Stenodynerus steckianus, ♀. 40. Habitus, dorsal view. 41. Head, frontal view. 42. Pronotum, dorsal view. 43. Propodeum, dorsal view. 44. Metasomal segments 2–6, lateral view. 45. T1–T6, dorsal view. 46. S2–S6, ventral view.

FIGURES 47–57. Stenodynerus trotzinai (47, 49, 51, 53–56, ♀; 48, 50, 52, 57, ♂). 47, 48. Habitus, dorsal view. 49, 50. Head, frontal view. 51. Pronotum, frontal view. 52. Antenna. 53. T1–T6, dorsal view. 54. S2–S6, ventral view. 55. Propodeum, dorsal view. 56. Metasomal segments 2–6, lateral view. 57. Genitalia, ventral view.