Key to East Palaearctic species of the genus Leluthia Cameron
1. Antescutal depression present; mesoscutum weakly and gradually elevated above pronotum (Figs 1, 6); mesosoma 2.0–3.6 × longer than high; vein 1-M of hind wing of ♀ 2.0–3.0 × vein 1r-m (Fig. 11); subgenus Leluthia Cameron. ............... 2
- Antescutal depression absent or weakly developed; mesoscutum steep anteriorly; mesosoma 1.6–2.0 × longer than high; vein 1-M of hind wing of ♀ 1.4–2.0 × vein 1r-m; subgenus Euhecabolodes Tobias. .................................... 5
2. Mesosoma about 3.6 × longer than high; antenna 0.8 × as long as its body; penultimate antennal segment 2.7 × longer than its maximum width..................................................... L. nagoyae Belokobylskij & Maetô, 2006
- Mesosoma 2.2–2.7 (rarely up to 3.0) × longer than high; antenna 0.9–1.0 × as long as its body; penultimate antennal segment 3.0–4.0 × longer than its maximum width.................................................................. 3
3. Second metasomal suture distinctly curved sublaterally; pterostigma of ♀ 2.7–3.0 × longer than its maximum width........................................................................ L. honshuensis Belokobylskij & Maetô, 2006
- Second metasomal suture weakly curved laterally; pterostigma of ♀ 3.0–4.0 × longer than its maximum width........... 4
4. Vein r-m of fore wing of ♀ present; hind telotarsus yellow; vein m-cu of hind wing of ♀ interstitial with vein 1r-m; hind leg light to dark reddish brown.................................................. L. disrupta (Belokobylskij, 1994)
- Vein r-m of fore wing of ♀ absent (Fig. 11), but weakly developed in ♂ (Fig. 12); hind telotarsus dark brown; vein m-cu of hind wing of ♀ far antefurcal (Figs 11–12); hind leg yellowish brown.......... L. chinensis Li & van Achterberg, sp. nov.
5. Mesopleuron striate below precoxal sulcus; vein m-cu of fore wing postfurcal.. L. postfurcalis Belokobyskij & Maetô, 2006
- Mesopleuron without striae below precoxal sulcus; vein m-cu of fore wing antefurcal............................... 6
6. Vein 3-SR+SR1 of fore wing distinctly curved basally and ends far removed from wing apex; (= Euhecabolodes minutus Tobias, 1962)............................................................... L. ruguloscolyti (Fischer, 1962)
- Vein 3-SR+SR1 of fore wing straight basally and ends near apex of wing......................................... 7
7. Body pale reddish brown or yellowish brown; vein r of fore wing vertical.................... L. asiatica (Tobias, 1980)
- Body dark reddish brown or black, at most with some reddish brown spots; vein r of fore wing distinctly oblique; (= Euhe- cabolodes ulmi Tobias, 1980).................................................. L. transcaucasica (Tobias, 1976)