Key to Cardiocondyla species in the southeastern United States (from Creighton 1950; Seifert )
1 In anterodorsolateral view the postpetiolar sternite with prominent anterolateral corners, anterior corners appear concave (fig. 1 A); color yellowish brown to reddish brown to bicolored with yellowish brown body and dark brown gaster (fig. 2A)
1' Postpetiolar sternite without prominent anterolateral corners (fig. 1B); reddish brown to dark brown (figs. 2B and 2C)

 

Figure 1. Profile views of petiole and postpetiole of Cardiocondyla spp. (A) C. wroughtonii - note angular corner of postpetiole on anterior portion of sternite and concave appearance anteriorly. (B) C. minutior - postpetiole rounded anteriorly.

Figure 2. Profile views of Cardiocondyla spp. showing color differences. (A) yellowish color, (B) bicolored reddish brown with dark gaster, and (C) dark brown.

 

2(1) Gaster yellowish brown except with diffuse dark band on posterior half of first tergite or first tergite entirely dark brown and following tergites lighter (fig. 3A)
2' Entire gaster dark (fig. 3B)

 

Figure 3. Gasters of Cardiocondyla spp. (A) C. wroughtonii - yellowish gaster, (B) C. obscurior - dark brownish black gaster.

 

3(1) Bicolored reddish brown with dark brown gaster; spines elongate; mesonotal suture distinct, deeply impressed (fig. 4A)
3' Concolorous dark brown; mesonotal suture less impressed (fig. 4B)

 

Figure 4. (A) C. emeryi - bicolored, long spines, deep mesonotal suture, (B) C. obscurior - dark brown, shorter spines, mesonotal suture more shallow.

 

4(3) Head only slightly longer than wide (fig. 5A); 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 (fig. 7A); length of pubescence on the gaster short (fig. 7A)
4' Head elongate (fig. 5B); 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 (fig. 6B); sides of petiole and postpetiole with sculpture, not shining (fig. 7B); length of pubescence on gaster longer (fig. 7B)

 

Figure 5. (A) C. venustula - squarish shaped head, (B) C. minutior - elongate head.

Figure 6. (A) Alitrunk of C. venustula - arrows point to slight mesonotal impression and to reduced, denticle-like propodeal spine, (B) alitrunk of C. minutior - arrows point to indistinct mesonotal impression and longer spines.

Figure 7. (A) C. venustula - shiny petiole and postpetiole and shorter pubescence on gaster, (B) C. minutior - sculptured petiole and postpetiole and longer pubescence on gaster.

 

Literature Cited

Creighton, W.S. 1950.  The Ants of North America. Bulletin: Museum of Comparative Zoology 104:  1-585. 

Seifert, B. 2003. The ant genus Cardiocondyla (Insecta: Hymenoptera: Formicidae) - a taxonomic revision of the C. elegans, C. bulgarica, C. batesii, C. nuda, C. shuckardi, C. stambuloffii, C. wroughtonii, C. emeryi, and C. minutior species groups. Ann. Naturhist. Mus. Wien. B. Bot. Zool. 104(B): 203-338.