Taxonomy and Natural History of the Crematogaster (Decacrema) - group (Hymenoptera: Formicidae) in Madagascar Author Blaimer, Bonnie B. text Zootaxa 2010 2714 1 39 journal article 10.5281/zenodo.199681 62e1623e-d85e-46ea-8edf-6cb01d7c88eb 1175-5326 199681 Key to the Subgenera of the Crematogaster of the Malagasy region: Workers 1. Antennae 10-segmented................................................................................................................................ Decacrema - Antennae 11-segmented................................................................................................................................................ 2 2(1) Petiole in dorsal view rectangular, with four angular or acute corners ( Fig. 12 ); very small species (HW <0.75, WL <0.75) ............................................................................................................................................................ Mesocrema - Petiole in dorsal view variable, but never rectangular; size variable............................................................................ 3 3(2) Petiole in dorsal view ovo-rectangular ( Fig. 13 ), with anterior corners rounded and posterior corners angular or acute, and dorsal face flat; dorso-lateral margins of metanotum carinate ( Fig. 14 ) or angular ( Fig. 15 ), with at least 1 long, flexible seta on either side; very small to small species (HW <0.90, WL <0.90) ............................ Orthocrema - Petiole shape variable, if ovo-rectangular, then dorsal face concave; dorso-lateral margins of metanotum never carinate; size variable..........................................................................................................................................................4 4(3) Anterior margin of clypeus medially protruding as thin flange over mandibles ( Fig. 18 ), anterior part of clypeus transversely concave; subpetiolar tooth or protrusion absent, petiolar stalk narrow ( Fig. 16 b); petiole shape usually more or less slender and suboval ( Fig. 16 a), rarely flared or oval ................................................................... Oxygyne - Anterior margin of clypeus never medially protruding over mandibles ( Fig. 19 ), anterior part of clypeus transversely convex; subpetiolar tooth or protrusion mostly present, variable in size and form, if close to absent ( Fig. 17 b), then petiole broadly flared anteriorly ( Fig. 17 a) and distinctly wider than long, never slender and suboval; otherwise petiole shape variable. ................................................................................................................................... Crematogaster