Key to world species of Glodianus
1. Mesoscutum black. Hind femur red. Mexico ............................................................... 2
- Mesosoma completely red. Hind femur black............................................................... 3
2. Tergite 2 with preapical white transverse band and hind margin darkened. Mesoscutum with a pair of large yellow spots laterally........................................................... 2. G. graciliventris (Cameron), sp. resurr.
- Tergite 2 with hind margin white. Mesoscutum entirely black............................... 1. G. delectus (Cresson)
3. Metasomal tergites without white markings apically......................................................... 4
- Metasomal tergites with hind margins white................................................................ 5
4. Hind tarsus black, ♂........ G. dimidiatus (Brullé, 1846) [South America], or G. xanthostomus Cameron, 1911 [Guyana]
- Hind tarsus black but with white band on tarsomeres 2–4. [Metasomal tergites with hind margins pale reddish brown. Lateral lobes of mesoscutum partly strongly transversely striated. Propodeum with apophyses broad, moderately projected. Wings strongly iridescent. Ovipositor almost 0.8× as long as body.] Peru .................... G. bombycivorus Cameron, 1902
5. Metasomal tergites with postmedian whitish yellow mark on each tergite (mark lanceolate of tergite 2 and widened medially of following tergites). [Ovipositor slightly longer than half length of metasoma.] South America................................................................................................... G. peruvianus Szépligeti, 1916
- Metasomal tergites without postmedian white marks......................................................... 6
6. Ovipositor slightly longer than body. [Hind coxa and trochanter posteriorly red, hind trochantellus, femur and tibia black.] Guyana ...................................................................... G. pallidiceps Cameron, 1911
- Ovipositor shorter than body............................................................................ 7
7. Ovipositor longer than metasoma. South America.................................... G. longicauda (Brullé, 1846)
- Ovipositor about 0.4× as long as metasoma................................................................ 8
8. Hind leg with basitarsus black in basal 0.7 and white in apical 0.3 (Fig. 11). Fore wing with areolet receiving vein 2m-cu at anteior 0.45 (Fig. 11). Venezuela ............................................... G. areolatus (Taschenberg, 1876)
- Hind legs with basitarsus black in basal 0.2–0.3 and white in apical 0.7–0.8 (Fig. 8). Fore wing with areolet receiving vein 2m-cu at posterior 0.35 (Fig. 5). Mexico ................................................... 3. G. rufithorax sp. nov.