Ichneumoninae, Latreille, 1802

Dal Pos, Davide, Heilman, Victoria & Welter-Schultes, Francisco, 2022, Platylabini (Hymenoptera: Ichneumonidae: Ichneumoninae) of the south-eastern United States: new distributional data, taxonomic notes, illustrated keys, and an annotated catalogue of the genera and species, Journal of Natural History 56, pp. 1869-1938 : 1874-1878

Key to the tribes of Ichneumoninae of North America and genera of Platylabini of the south-eastern United States

The following key is based on the results from Santos et al. (2021) and adapted from Heinrich (1961, 1962b), Tereshkin (2009), and Valemberg (2014). Since the character ‘first metasomal tergite broader than high’ (first couplet) can be difficult to score, Apaeleticus and Probolus can be keyed out from both statements in the first couplet.

1. First metasomal tergite wider than high with postpetiole dorsally strongly flattened ( Figure 2a ); clypeus gently to strongly convex ( Figure 3a ); metasoma of females amblypygous ( Figures 13b , 22b , 26b , 32b , 34b , 36a ) ....... 2 ( Platylabini )

- First metasomal tergite not wider than high with postpetiole not dorsally strongly flattened ( Figure 2b ); clypeus either gently to strongly convex or entirely flat and wide ( Figure 3b ); metasoma of females amblypygous, oxypygous or semyamblypygous (fig. 2 in Santos et al. (2021))........................................................................................... 10

2. Postpetiolus, in lateral view, with an anterior hump medially ( Figure 4b ); sternites strongly sclerotised ( Figure 34b ); horizontal part of propodeum lacking distinct carinae ( Figure 43d )............................................................................ Probolus Wesmael, 1845

- Postpetiolus, in lateral view, without an anterior hump medially ( Figure 4a ); sternites not strongly sclerotised ( Figures 5a , 7c , 9b , 11b , 13b , 40a, 40d ); horizontal part of propodeum with distinct carinae or with a rough reticulate-cellular sculpture ( Figures 5d , 7a , 15d , 26d )............................................................................................................................. 3

3. Propodeum with long, pointed apophyses in both sexes ( Figures 5d , 37a ); area superomedia and area basalis not separated but forming together an area gradually widening towards the scutellum ( Figure 5d ); gastrocoeli relatively superficial, with thyridia smaller than the space between them ( Figure 5d ).................................................... ............................................................................................................... Ambloplisus Heinrich, 1930

- Propodeum without long apophyses, or at most with short, tooth-like projections ( Figures 22b , 26d , 32b , 37b ); area superomedia otherwise shaped, not fused with area basalis ( Figures 13e , 20b , 22d , 26d ); gastrocoeli and thryridia of various shapes........ 4

4. Spiracles of propodeum elongate, usually considerably longer than wide (ovate or linear) ( Figures 9b , 22b, 22d , 37b )................................................................................................. 5

- Spiracles of propodeum small and circular ( Figures 11b , 13e )......................................... 7

5. Gastrocoeli superficial; thyridia indistinct ( Figure 9d ) ....................................................... ...................................................................................................... Asthenolabus Heinrich, 1951

- Gastrocoeli large and rather deep; thyridia usually larger than the space between them ( Figures 4a , 22d , 36c )............................................................................................................. 6

6. Mandible not twisted, appearing bidentate in frontal view; propodeal carinae not lamellate ( Figure 22d ); face not broad in frontal view, genae not strongly inflated ( Figure 22c ) ........................................................................................ Platylabus Wesmael, 1845

- Mandibles twisted, appearing unidentate in frontal view; propodeal carinae strong and lamellate ( Figure 37b ); face broad in frontal view, genae strongly inflated ( Figure 38b ).................................................................................... Tropicolabus Heinrich, 1859

7. Propodeum with rough reticulate-cellular sculpture, carinae of propodeal areas indistinct, sinuate ( Figure 7a ); middle field of face strongly protruding ( Figure 7c ); gastrocoeli transverse and rather distinct; in females tergites 6 and 7 retracted under the 5th tergite ( Figure 7c ).......................................................... Apaeleticus Wesmael, 1845

- Propodeum usually without rough reticulate-cellular sculpture, carinae of propodeum distinct ( Figures 13e , 15d , 20b ); gastrocoeli either distinct or subobsolete ( Figures 13e , 15d ); apical tergites of females not retracted ( Figures 13b , 5b ).. 8

8. Gastrocoeli strongly impressed;thyridia larger than the space between them ( Figure 13e ) ................................................................................................................................. Cyclolabus Heinrich, 1836

- Gastrocoeli superficial; thyridia indistinct or at most as large as the space between them ( Figures 15d , 20b )................................................................................................................................................ 9

9. Gastrocoeli represented by a narrow and superficial, oblique, longitudinal depression, bearing some coarse, irregular, longitudinal rugae, their interspace and anterior half of 2nd tergite coarsely and densely, irregularly rugose; thyridia indistinct ( Figure 15d ); areolet clearly pentagonal ( Figure 15b ); temples not very reduced in lateral view ( Figure 15b ).................................................................................... Linycus Cameron, 1903

- Gastrocoeli superficial and thyridia transverse, each about as wide as their interspace; anterior part of 2nd tergite, including space of gastrocoeli, without rugosity ( Figures 17a , 18 , 19 , 20b, 20c, 20f ); areolet rhomboidal ( Figure 20e ); temples very reduced in lateral view ( Figures 20a, 20d, 20e ).......... Neolinycus Heinrich, 1971

10. Spiracles of propodeum small and circular ( Figures 9b , 22b , 26d , 37b ); clypeus from gently to strongly convex ( Figures 3a , 7b ) ............................................................................. 11

- Spiracles of propodeum elongate, usually considerably longer than wide (ovate or linear) ( Figures 22b , 26d ); clypeus flat and wide or slighlty convex ( Figures 3b , 34c ).......................................................................................................................................................... 12

11. Propodeum with rough reticulate-cellular sculpture, carinae and propodeal areas indistinct, sinuate ( Figure 13c )...................................................................... Apaeleticus Wesmael, 1845 (Platylabini)

- Propodeum without rough reticulate-cellular sculpture, carinae and propodeal areas distinct ................................................................................................................ Phaeogenini (not treated here)

12. Horizontal part of the propodeum without distinct carinae ( Figure 34b ); postpetiolus, in lateral view, with an anterior hump medially ( Figure 5b ); sternites strongly sclerotised ( Figure 34b ); clypeus slightly convex ( Figure 34c ); female metasoma always amblypygous ( Figure 34b ) .............................................................. Probolus Wesmael, 1845 (Platylabini)

- Horizontal part of the propodeum with distinct carinae; postpetiolus, in lateral view, usually without an anterior hump medially, if hump present (e.g. Patrocloides montanus ( Cresson, 1864)) , then propodeum with distinct carinae; sternites from strongly sclerotised to completely unsclerotised; female metasoma amblypygous, semiamblypygous or oxypygous (fig. 2 in Santos et al. (2021))............................ Ichneumonini (not treated here)

Figures

Figure 2. Comparison of a petiole between Ichenumonini and Platylabini, dorso-lateral view. a) Coelichneumon azotus (Cresson, 1864) (Ichneumonini). b) Platylabus clarus (Cresson, 1867) (Platylabini).

Figure 3. Comparison of the clypeus between Phaoegenini (convex) and Ichneumonini (flat), frontal view. a) Terebraella culiciops Heinrich, 1972 (Phaeogenini). b) Coelichneumon azotus (Cresson, 1864) (Ichneumonini).

Figure 4. Petiole, lateral view. a) Platylabus clarus (Cresson, 1867). b) Probolus detritus (Brullé, 1846).

Figure 5. Ambloplisus ornatus (Cresson, 1868), ♀. a) Habitus, lateral view. b) Head, frontal view. c) Head and mesosoma, dorsal view. d) Propodeum and metasoma, dorsal view.

Figure 7. Apaeleticus americanus Cushman, 1926, holotype ♀. a) Habitus, dorsal view. b) Head, frontal view. c) Habitus, lateral view. d) Labels.Downloaded from the public USNM database (available also at http://n2t.net/ark:/65665/3b8484f3e-e496-4e57-a931-64842bace133).

Figure 9. Asthenolabus canadensis (Cresson, 1877), ♀. a) Habitus, dorsal view. b) Habitus, lateral view. c) Head, frontal view. d) Propodeum and metasoma, dorsal view.

Figure 11. Cyclolabus carolinensis Heinrich, 1962, holotype ♀. a) Habitus, dorsal view. b) Habitus, lateral view. c) Head, frontal view. d) Labels.

Figure 13. Cyclolabus gracilicornis gracilicornis (Provancher, 1886), lectotype ♀. a) Habitus, dorsal view. b) Habitus, lateral view. c) Head, frontal view. d) Labels. e) Mesosoma and metasoma, dorsal view. Downloaded from the public CNCI database (available also at https://www.cnc.agr.gc.ca/taxonomy/ Gallery.php).

Figure 15. Linycus exhortaor thoracicus (Cresson, 1864), ♀. a) Habitus, dorsal view. b) Habitus, lateral view. c) Head, frontal view. d) Propodeum and metasoma, dorsal view.

Figure 17. Neolinycus michaelis Heinrich 1971, holotype ♀. a) Habitus, dorsal view. b) Habitus, lateral view. c) Labels. From Schmidt (2021a).

Figure 18. Neolinycus michaelis georgianus Heinrich, 1972, holotype ♀. a) Habitus, dorsal view. b) Habitus, lateral view. c) Labels. From Schmidt (2021b).

Figure 19. Neolinycus michaelis arkansae Heinrich, 1977, holotype ♂. a) Habitus, dorsal view. b) Habitus, lateral view. c) Labels. From Schmidt (2021c).

Figure 20. Neolinycus michaelis Heinrich, 1971, colour variation. a) Habitus, lateral view, ♂. b) Habitus, dorsal view, ♂. c) Habitus, dorsal view, ♂. d) Habitus lateral view, ♂. e) Habitus, lateral view, ♀. f) Habitus, dorsal view, ♀.

Figure 22. Platylabus clarus (Cresson, 1867), ♀. a) Habitus, dorsal view. b) Habitus, lateral view. c) Head, frontal view. d) Propodeum and metasoma, dorsal view.

Figure 26. Platylabus opaculus americanus Heinrich, 1962, ♀. a) Habitus,dorsal view. b) Habitus,lateral view. c) Head, frontal view. d) Propodeum and metasoma, dorsal view.

Figure 32. Platylabus rubristernatus Heinrich, 1962, holotype ♀. a) Habitus, dorsal view.

Figure 34. Probolus detritus (Brullé, 1846), ♀. a) Habitus, dorsal view. b) Habitus, lateral view. c) Head, frontal view. d) Propodeum and metasoma, dorsal view.

Figure 36. Tropicolabus foxi (Davis, 1898), ♀. a) Habitus, lateral view. b) Mesoscutum and head, dorsolateral view. c) Metasoma, dorsal view.

Figure 37. Propodeum and metasoma, dorso-lateral view. a) Ambloplisus ornatus (Cresson, 1868). b) Tropicolabus foxi (Davis, 1898).

Figure 38. Face, frontal view. a) Ambloplisus ornatus (Cresson, 1868), holotype ♀. b) Tropicolabus foxi (Davis, 1898), holotype ♀.

Figure 40. Comparison of holotypes of Ambloplisus ornatus (Cresson, 1868) and Tropicolabus foxi (Davis, 1898). a) Ambloplisus ornatus (Cresson, 1868), habitus, dorsal view. b) Ambloplisus ornatus (Cresson, 1868), habitus, lateral view. c) Ambloplisus ornatus (Cresson, 1868), labels. d) Tropicolabis foxi (Davis, 1898), habitus, dorsal view. e) Tropicolabus foxi (Davis, 1898), habitus, lateral view. f) Tropicolabis foxi (Davis, 1898), labels.

Figure 43. Number of Ichneumoninae species per state in the United States of America.