Eusterinx, Forster, 1869

Humala, A. E., 2025, A review of Mexican species of the genus Eusterinx (Hymenoptera: Ichneumonidae: Orthocentrinae), Zoosystematica Rossica (China) 34 (1), pp. 149-159 : 150-151

Key to Mexican species of the genus Eusterinx

1. At least tergites 2 and 3 crossed by deep transverse furrows...................................... 2

– Metasomal tergites not crossed by transverse furrows......................................... 3

2. First metasomal segment 2.2 times as long as wide posteriorly, its dorsal carinae distinct; tergites 1–4 longitudinally striate with coarser sculpture on anterior parts of tergites; hind coxa yellowish brown................................. E. inaequalis

– First metasomal segment slenderer, 3.7 times as long as wide posteriorly, without distinct dorsal carinae; tergites 1–4 entirely coriaceous, without longitudinal striae; hind coxa fuscous......... E. longipes

3. Fore wing with areolet and dark transverse medi- an and apical bands; flagellum with light medi- an band ( Figs 10, 16); epicnemial carina strongly expanded medioventrally into conspicuous lobe; orange-brown species with tricolourous metasoma ( Fig. 16); large species: body length 6.6–15.0 mm, fore wing length 4.7–11.0 mm........ E. madorae

– Fore wing without areolet and dark bands; flagellum without light band; epicnemial carina not modified; generally darker species with metasoma not as above; smaller species: body length at most 3.8 mm, fore wing at most 3.5 mm ...................... 4

4. Propodeum with long, flattened, apically rounded apophyses ( Fig. 18); inner eye orbits convergent towards clypeus.................. E. tenuiventris

– Propodeum with small sharpened apophyses (as high as diameter of flagellum) or without apophyses; inner eye orbits subparallel...................... 5

5. Hind tarsal claws and tarsomere 5 enlarged; hind femur inflated, 3.5 times as long as wide; hind coxa and femur predominantly blackish; propodeum with small apophyses ( Fig. 17); eyes with short inconspicuous setae..................... E. solida

– Hind tarsal claws and tarsomere 5 not enlarged; hind femur slenderer, 4.25–5.0 times as long as wide; hind leg pale brown or lighter; propodeum without apophyses; eyes glabrous....................... 6

6. Notauli deep and long, extending to middle of mesoscutum.................................. 7

– Notauli weak and short, not reaching middle of mesoscutum.................................. 8

7. Ovipositor slightly upcurved, 0.4 times as long as hind tibia ( Fig. 1); antenna of female with 20–21 flagellomeres, 3–4 apical flagellomeres pale ( Fig. 2); metasoma predominantly fuscous, tergites 2–3 with yellowish brown markings ( Figs 1, 6)............................... E. apicicornis sp. nov.

– Ovipositor straight, 0.75–0.8 times as long as hind tibia; antenna of female with 16–20 flagellomeres, apical flagellomeres fuscous; tergites 1–3 predominantly rufous...................... E. australis

8. Ovipositor strongly upcurved, 0.85–1.0 times as long as hind tibia; antenna of female with 19 flagellomeres; tyloids developed on male flagellomere 6........................ E. americana nom. nov.

– Ovipositor straight, 1.15–1.25 times as long as hind tibia; antenna of female with 17–18 flagellomeres; tyloids lacking on male flagellomeres................................................ E. townesi