Key to Gasteruptiidae Ashmead, 1900 of New Caledonia (modified from Jennings et al. 2015)

1. Mandibles long and broadly overlapping when in closed position; prefemur absent; female subgenital sternite simple; ovipositor short and usually hidden ................2 ( Hyptiogastrinae Crosskey, 1953)

– Mandibles short and not broadly overlapping when in closed position; prefemur present; female subgenital sternite notched; ovipositor exserted ........................ 3 ( Gasteruptiinae Ashmead, 1900)

2. Two distinct medial teeth on mandible; frontal carina present (Jennings & Austin 2005: figs 1–2) .......................................................... Pseudofoenus caledonicus Jennings & Austin, 2005

– Single weak medial tooth on mandible; frontal carina absent ............................................................ ............................................................................................... Pseudofoenus ritae (Cheesman, 1936)

3. Fore wing with first discal cell absent (Fig. 8E); hind tibia with a white large sub-basal ring; ovipositor with a white large sub-apical ring .................................................... Gasteruption jenningsi sp. nov.

– Fore wing with first discal cell present (Jennings et al. 2015: fig. 3); hind tibia with at most a small sub-basal whitish ring; ovipositor without a white sub-apical ring .................................................. 4

4. Large species, length 25.7 mm; fore wing vein 2-M tubular in apical third, tubular portion ending with small node; hind wing with 2m + Cu melanised, 1-Cu, 1-m and r-m present (Jennings et al. 2015: fig. 3) ......................................... Gasteruption maquis Jennings, Krogmann & Parslow, 2015

– Small species, length less than 12 mm; fore wing vein 2-M tubular in apical third, tubular portion not ending with small node; hind wing with not melanised 2m + Cu, 1-Cu, 1-m and r-m absent (Jennings et al. 2015: figs 2–4) ......................................................................................................................... 5

5. Head more or less quadrate, 0.94 × as long as wide when viewed dorsally; propleuron short, 0.84 × as long as pronotum; frontal carina present (Jennings et al. 2015: figs 6, 12) ................................... ........................................................... Gasteruption lacoulee Jennings, Krogmann & Parslow, 2015

– Head elongate, 1.48 × as long as wide when viewed dorsally; propleuron long, 1.64 × as long as pronotum; frontal carina absent (Jennings et al. 2015: figs 10, 16) ................................................... ......................................................... Gasteruption sarramea Jennings, Krogmann & Parslow, 2015