Ischyracis Förster, 1869

Humala, Andrei E., 2024, First record of the genus Eusterinx Förster (Hymenoptera: Ichneumonidae: Orthocentrinae) from the Afrotropical Region, with description of a new species from South Africa, Zootaxa 5537 (2), pp. 281-287 : 282-283

Subgenus Ischyracis Förster, 1869

Acanthostroblia Roman, 1925 .

Cymodusoides Viereck, 1925 .

Stroblia Schmiedeknecht, 1911 .

Type species: Eusterinx (Ischyracis) bispinosa (Strobl, 1901)

Diagnosis

The subgenus Ischyracis is recognizable by the following characters: propodeum with well-developed apophyses; eye large or very large, strongly convex, female inner orbits distinctly convergent to clypeus (to a lesser extent in males); male with concave tyloid on 6th flagellomere. Fore wing with or without petiolate areolet.

Six species were previously known in this subgenus: Holarctic E. (I.) bispinosa (Strobl, 1901) , Oriental E. (I.) ganica Sheng et Sun, 2013 from China, three East Palaearctic species: E. (I.) fulvipes Humala et Lee, 2017 , E. (I.) petiolata Humala et Lee, 2017 and E. (I.) rufithorax Humala et Lee, 2017 from South Korea, and E. (I.) tenuiventris Humala et Ruiz, 2017 from Mexico. The subgenus Dallatorrea Ashmead, 1902 with four known Holarctic species ( E. armata (Ashmead, 1902) , E. circaea Rossem, 1982 , E. recurvata Dasch, 1992 , E. rufula (Provancher, 1879)) is reduced to the synonym of Ischyracis Förster, 1869 syn. n., as all key characters except presence/absence of closed areolet in fore wing occur in both subgenera or overlapping. It should be pointed out that the presence of a vein 3 rs-m closing the areolet posteriorly is an unreliable character, because, for example, within another Eusterinx subgenus, Trestis , it can be either well developed, partially reduced or completely absent.

Key to Ischyracis species of the world fauna

1. Fore wing with closed areolet............................................................................ 2

- Fore wing without areolet............................................................................... 6

2. Hind femur 3.45–4.0 × as long as wide; mesosoma rufous; epicnemial carina extending to subtegular ridge; anterior metasomal tergites longitudinally striate. Ovipositor 0.5–0.55 × as long as hind tibia, nearly straight................. 3

- Hind femur 4.4–5.0 × as long as wide; epicnemial carina ending opposite middle of pronotum; mesosoma mostly fuscous; metasomal tergites not striate, or at most, weakly on T1; Ovipositor 0.65–0.85 × as long as hind tibia................... 4

3. Antenna with 15–17 flagellomeres, first flagellomere 4.75–4.85 × as long as wide. Metasoma extensively rufous; T1 3.0–3.55 × as long as posterior width; T2 0.8–1.05 × as long as posterior width..................... rufula (Provancher) (Nearctic)

- Antenna with 19 flagellomeres, first flagellomere 7.5 × as long as wide. Metasoma brown, posterior margins of T1–T5 yellowish. T1 3.8 × as long as posterior width; T2 1.2 × as long as posterior width … rufithorax Humala et Lee ( South Korea)

4. Notauli shallow, mesosoma rufous on recurved humeral bars, disk of mesoscutum, and scutellum..................................................................................................... recurvata Dasch (Nearctic)

- Notauli deep, mesosoma entirely fuscous.................................................................. 5

5. Face very narrow, width 0.13–0.15 × head width in female, Antenna with 19–23 flagellomeres, first flagellomere 5.45–6.15 × as long as wide. Hind leg mostly rufous. Ovipositor 0.65–0.8 × as long as hind tibia, T2 1.25–1.5 × as long as posterior width........................................................................ armata (Ashmead) (Nearctic)

- Face width 0.3 × head width in female, Antenna comparatively short, with 17 flagellomeres, first flagellomere nearly 5.0 × as long as wide. Hind coxa dark brown. Ovipositor 0.4 × as long as hind tibia; T2 as long as posterior width......................................................................................... circaea Rossem (Palaearctic)

6. Nervulus distinctly postfurcal. Metapleuron with reticulate sculpture; metasoma slender, T1 4.2 × as long as posterior width; T2 2.2 × as long as posterior width, with rough longitudinal wrinkles................................................................................................... tenuiventris Humala et Ruiz ( Mexico) [female unknown]

- Nervulus interstitial. Metapleuron without rough reticulate sculpture; metasoma various............................. 7

7. Ovipositor short, 0.45–0.5 × as long as hind tibia; lower mesopleuron polished; hind femur 5.0–5.3 × as long as wide...... 8

- Ovipositor 0.85–1.0 × as long as hind tibia; lower mesopleuron polished or with longitudinal striae; hind femur 4.8–5.5 × as long as wide........................................................................................ 10

8. Small species, body length 3.6 mm, fore wing 2.7 mm; occipital carina developed only in dorsal part; area superomedia narrow, 2.5 × as long as maximum wide; T2 1.35 × as long as maximum wide posteriorly; hind coxa dark-brown... africana sp. nov.

- Larger species; body length 4.2– 6.3 mm, fore wing 3.7–5.0 mm; occipital carina complete; area superomedia 1.2 –1.8× as long as maximum wide; T2 1.6–2.0 × as long as maximum wide posteriorly; hind coxa mostly yellow...................... 9

9. Body length 6.3 mm, fore wing 5.0 mm; antenna with 23 flagellomeres, distinctly longer than fore wing; inner orbits strongly convergent to clypeus; longitudinal striae on T1–5; T2 2.0 × as long as posterior width...... ganica Sheng et Sun (Oriental)

- Body length 4.2 mm, fore wing 3.7 mm; antenna with 18 flagellomeres, nearly as long as fore wing; inner orbits moderately convergent downwards; longitudinal striae on T1–3; T2 1.6 × as long as posterior width.................................................................................................... fulvipes Humala et Lee ( South Korea)

10. Lower mesopleuron polished; T1 smooth, 4.2 × as long as posterior width, T2 2.1 × as long as posterior width; first flagellomere 7.0 × as long as wide; hind coxa polished, infuscate in basal half; hind femur yellowish.................................................................................................... petiolata Humala et Lee ( South Korea)

- Lower mesopleuron longitudinally striate; T1 longitudinally striate; T2 0.9–1.35 × as long as posterior width; first flagellomere 3.2–5.0 ×as long as wide; hind coxa coriaceous, black; hind femur dark brown.............. bispinosa (Strobl) (Holarctic)