Key to Eucremastus species of Saudi Arabia (based on females)

1. Body entirely lemon yellow (Fig. 4 A, B); fore wing vein Rs distinctly concave ventrally (Fig. 5 A); pterostigma broadly triangular, 2.9 × as long as broad; fore wing vein R1 about as long as pterostigmal length (Fig. 5 A).......... E. flavus sp. nov.

- Body ivory white, with few black especially on metasomal T2 medio-basally (Figs 2 A, 8A); fore wing vein Rs slightly concave to nearly straight ventrally; pterostigma narrowly triangular, 3.8‾4.0 × as long as broad; fore wing vein R1 shorter than

pterostigmal length (0.7‾0.8 ×)......................................................................... 2 2. Antenna with distinctly dark brown flagellomeres (Fig. 8 D); antenna with 29 flagellomeres; ocelli small; MOD 1.3 × OOD; IOD 2.0 × OOD (Fig. 8 B, D)........................................................ E. rufoantennalis sp. nov. - Antenna with pale brown to yellowish or ivory white flagellomeres (Fig. 2 C); antenna with 34 flagellomeres; ocelli large; MOD 1.6 × OOD; IOD 2.5 × OOD (Fig. 2 B, C).............................................. E. arabicus sp. nov.