Sphinctomyrmex Mayr, 1866

W. Jaitrong, D. Wiwatwitaya & W. Sakchoowong, 2016, Review of the Thai Species of the Genus Sphinctomyrmex Mayr, 1866 (Hymenoptera: Formicidae, Dorylinae), with Description of a New Species, Far Eastern Entomologist 305, pp. 1-9 : 3

Genus Sphinctomyrmex Mayr, 1866

Key to Asian species of Sphinctomyrmex based on worker caste

1 Antenna 12-segmented; eyes absent; pygidial apex truncate as seen from above; smaller species (WL 0.89-0.92 mm); gastral segments II, III, and IV nearly equal to one another in width and length ( Fig. 7) (Thailand) ................................ ................................................................................................ S. siamensis sp. n.

– Antenna 11-segmented; eyes present but small; pygidial apex deeply notched as seen from above; larger species (WL 1.27-1.78 mm); gastral segment II clearly larger than each of segments III and IV in width and length ( Fig. 3) ................. 2

2 Larger species (WL 1.68-1.78 mm); body deep reddish brown; petiolar node longer than broad (India, Myanmar, and Thailand) ... S. furcatus (Emery, 1893)

– Smaller species (WL 1.27 mm); body light reddish brown; petiolar node broader than long (India) ................................................................ S. taylori Forel, 1900