Crematogaster

Blaimer, Bonnie B., 2010, Taxonomy and Natural History of the Crematogaster (Decacrema) - group (Hymenoptera: Formicidae) in Madagascar, Zootaxa 2714, pp. 1-39 : 7-8

Key to the Subgenera of the Crematogaster of the Malagasy region: Queens

(as far as queens are known)

1 Antennae 10-segmented. ............................................................................................................................... Decacrema

- Antennae 11-segmented................................................................................................................................................ 2

2(1) Mandibles sickle-shaped with single apical tooth ( Fig. 18 ), very rarely with 4 teeth where apical tooth enlarged and 3 additional normal-sized teeth present; clypeus medially protruding as thin flange over mandibles ( Fig. 18 ) ............

.......................................................................................................................................................................... Oxygyne - Mandibles broad with 4–5 teeth, apical tooth at most slightly enlarged ( Fig. 19 ); clypeus not protruding over mandibles ( Fig. 19 ) ................................................................................................................................................................. 3

3(2) Petiole in dorsal view rectangular ( Fig. 12 ); propodeal spines absent ........................................................ Mesocrema

- Petiole in dorsal view variable, but never rectangular; propodeal spines variable.......................................................4

4(3) Petiole in dorsal view ovo-rectangular ( Fig. 13 ) and with postero-lateral denticles or tubercules; postpetiole without median impression ....................................................................................................................................... Orthocrema

- Petiole shape variable, but never ovo-rectangular, postero-lateral denticles absent; postpetiole variable, but at least posteriorly with weak median impression ............................................................................................. Crematogaster

Figures

FIGURES 12 – 19. Key to the ‘ subgenera’ present in Madagascar. 12: petiole in dorsal view rectangular; 13: petiole in dorsal view ovo – rectangular; 14: dorso – lateral margins of mesonotum carinate; 15: dorso-lateral margins of mesonotum angular; 16 a: petiole slender (in dorsal view) and b: petiolar stalk narrow (in lateral view); 17 a: petiole flared (in dorsal view) and b: petiolar tooth absent (in lateral view); 18: mandibles with a single apical tooth, sickle-shaped; 19: mandibles with 5 teeth, broad (this type of mandibles also often with 4 teeth).