Key to US Cardiocondyla species

Key to Cardiocondyla species from the United States based on workers. Modified from Creighton (1950), Seifert (2003) and Snelling (1974).

1

 * In anterodorsolateral view the postpetiolar sternite with prominent anterolateral corners, anterior corners appear concave; color yellowish brown to reddish brown to bicolored with yellowish brown body and dark brown gaster => 2
 * Postpetiolar sternite without prominent anterolateral corners; reddish brown to dark brown => 3

2

 * Gaster yellowish brown except with diffuse dark band on posterior half of first tergite or first tergite entirely dark brown and following tergites lighter => Cardiocondyla wroughtonii


 * Entire gaster dark => Cardiocondyla obscurior

3

 * Bicolored reddish brown with dark brown gaster; spines elongate; mesonotal suture distinct, deeply impressed => 4
 * Concolorous dark brown; mesonotal suture less impressed => 5

4

 * Head relatively broad and short; distance from anterior margin of eye to mandibular insertion approximately eye diameter; propodeal spines long; propodeal spines relatively sharp and spinose, length of to about ½ distance between tips; anterior clypeal border straight or slightly convex; note of petiole laterally compressed near apex => Cardiocondyla emeryi


 * Head relatively narrow and long; distance from anterior margin of eye to mandibular insertion 2/3 eye diameter; propodeal spines short; projections on propodeum angulate, not spinose, length about ¼ distance between tips; anterior clypeal border weakly concave; node of petiole not laterally compressed near apex => Cardiocondyla mauritanica

5

 * Head only slightly longer than wide; scapes long, not reaching the occipital margin by an amount less than the greatest thickness of the scape (fig. 5A); propodeum with a pair of very small denticles (not spinose); mesonotal sutures slightly impressed (fig. 6A); petiole and postpetiole shining in side view; length of pubescence on the gaster short => Cardiocondyla venustula


 * Head elongate; scapes shorter, not reaching the occipital margin by an amount at least as great as the first segment of the funiculus (fig. 5B); propodeum with a pair of relatively elongate spines (fig. 6B); mesonotal suture not noticeably impressed, in profile dorsum of alitrunk one continuous curve; sides of petiole and postpetiole with sculpture, not shining; length of pubescence on gaster longer => Cardiocondyla minutior