Key to the world Neuroscelio species:

1 T2 with costae developed at least basally (Figs. 3, 4, 10, 16, 22); body size variable ................................................. 2

– T2 entirely smooth, with no longitudinal costae; body length less than 1.6 mm ........................................................ 6

2 Vertex, mesoscutum and mesoscutellum finely coriaceous, with no punctures (Fig. 24); body length less than 1.4 mm; metascutellum unarmed, large ................................................................... N. orientalis Masner & Valerio n.sp.

– Vertex, mesoscutum and mesoscutellum punctate, punctures variable in size (Figs. 1, 2, 18); body length greater than 1.9 mm; metascutellum always armed with medial subtriangular projection ...................................................... 3

3 T2 with costate sculpture longest medially and shortest at sides, lateral margins of tergite smooth; mesoscutum and mesoscutellum mainly smooth except for fine scattered punctures ........ N. stirlingensis Galloway, Austin & Masner

– T2 with costate sculpture shortest medially and longest at sides (Fig. 3), or, all costae subequally long (Fig. 16); mesoscutum and mesoscutellum never with sculpture as described above, if punctures present then large and very clearly defined .............................................................................................................................................................. 4

4 Vertex predominantly smooth (Fig. 2); T2 with longitudinal costae of about the same length but sometimes costae weaker at meson (Fig. 4) .................................................................................. N. noyesi Galloway, Austin & Masner

– Vertex with coriaceous and scattered punctulate sculpture throughout or with large, dense punctures (Fig. 1); length of longitudinal costate sculpture on T2 variable .......................................................................................................... 5

5 T2 costae shortest medially, longest at sides, leaving large, smooth area posteromedially (Fig. 3); vertex, mesoscutum and mesoscutellum with large, dense punctures (Fig. 1) ........................... N. doddi Galloway, Austin & Masner

– T2 costae equally long, reaching almost to posterior margin of tergite, leaving only narrow smooth strip (Fig. 16); vertex, mesoscutum and lateral portions of mesoscutellum with fine coriaceous sculpture and fine scattered punctures (Fig. 18) .......................................................................................................... N. lagunai Valerio & Austin n.sp.

6 Propodeum with small but distinct medial tooth; posterodorsal part of mesosoma subhorizontal so that metanotum is clearly visible in dorsal view; antennal club entirely brown ............................................................ N. nervalis Dodd

– Propodeum without medial tooth; posterior margin of mesoscutellum virtually hides metanotum in dorsal view; two apical antennomeres yellow white, remainder brown ..................................... N. storeyi Galloway, Austin & Masner