Cardiocondyla britteni

Only known from a single specimen.

The type locality is West Didsbury to where it has apparently been imported via the Liverpool harbor with “Butter Beans”. Crawley (1920) wrote that “…It is highly probable that the ant was imported with the beans, in which case its place of origin would be tropical America…” The vernacular name Butter Beans is ambiguous but is most frequently referred to Lablab purpureus that has is natural origin most probably in SE Africa but its main cultivation areas in India (Maass et al., 2010). As no species of the C. minutior group has been found so far to be native in America or Africa, there is a good probability that the geographic origin of C. britteni is India or the Oriental region. (Seifert, 2022)

Identification
Seifert (2003) - By morphometry and body shape, Cardiocondyla britteni is undoubtedly a member of the Cardiocondyla minutior group. It differs from all other species of this group by much smaller and shallower foveolae on vertex, the shining head and dorsal areas of mesosoma, the shorter spines, and the larger sqrtPDG.

Seifert (2022) - Worker: Small size, CS 402 µm. Head much elongated CL/CW 1.249. Scape rather short, SL/CS 0.741. Postocular distance very large, PoOc/CL 0.482. Anterior clypeal margin convex. Occipital margin weakly concave. Eye small, EYE 0.226, with micropilae sparser and shorter than in Cardiocondyla minutior. Dorsal profile of mesosoma evenly convex and metanotal groove entirely absent. Spines very short (SP/CS 0.089), almost triangular and rather blunt. Petiole rather narrow (PeW/CS 0.268), in profile with a concave frontal face and convex node dorsum; the node in dorsal view almost globular. Postpetiole rather wide (PpW/CS 0.473) and moderately low (PpH/CS 0.272), its sternite very flat, without any prominent structures and in dorsal view with straight frontal margin and angulate-convex sides. Pubescence on whole body shorter and less dense than in C. minutior (PLF/CS 6.61%, sqPDG 4.25). Clypeus smooth. Frontal laminae and a small area caudal of them finely longitudinally carinulate. Dorsum of vertex, mesosoma, and waist in overall impression distinctly shiny. Vertex with very shallow and small foveolae of only 4–10 µm diameter; foveolar interspaces brilliantly shiny and much wider than foveolar diameter, occasionally with fragments of a very fine perifoveolar microreticulum. Surface structure of dorsal promesonotum similar to vertex. Whole propodeum as well as meso- and metapleurae weakly reticulate. Lateral area of pronotum smooth, finely microreticulate. Petiolar and postpetiolar nodes shiny, with very fine microreticulum. Dorsum of gaster smooth and with fragments of very fine microreticulum. Antennal club, gaster, propodeum, meta- and mesopleurae dark to blackish brown. Vertex, promesonotum, waist, and appendages light-yellowish brown.

By morphometry and body shape, Cardiocondyla britteni is undoubtedly a member of the C. minutior group. It differs from all other species of this group generally by the reduced sculpture on all body surfaces and in detail by the much smaller and shallower foveolae on vertex, the shiny head and dorsal areas of mesosoma, the shorter spines, and the larger sqPDG.

Distribution based on Regional Taxon Lists
Palaearctic Region: United Kingdom of Great Britain and Northern Ireland.

Nomenclature

 * . Cardiocondyla britteni Crawley, 1920c: 180, fig. (w.) GREAT BRITAIN.
 * Type-material: holotype worker.
 * Type-locality: Great Britain: England, West Didsbury, 12.v.1919 (H. Britten).
 * [Note: Crawley, 1920c: 180, says the single worker was most probably imported with butter beans, “in which case its place of origin would be tropical America”.]
 * Type-depository: OXUM.
 * Junior synonym of nuda: Radchenko, 1995b: 452.
 * Status as species: Donisthorpe, 1927b: 391; Bolton, 1995b: 132; Seifert, 2003a: 291 (redescription); Borowiec, L. 2014: 46.
 * Distribution: Britain.

Worker
Seifert (2003) - type: CS 402, CL/CW 1.249, SL/CS 0.741, PoOc/CL 0.482, EYE 0.226, dFOV 7.0, SP/CS 0.089, FRS/CS 0.242, SPBA/CS 0.283, PEW/CS 0.268, PPW/CS 0.473, PEH/CS 0.333, PPH/CS 0.272, PEW/PPW 0.563, sqrtPDG 4.25, PLG/CS 6.61 %, PigCap 7, PigMes 9, MGr/CS 0.0 %.

minute size. Head much elongated, CL/CW 1.249. Postocular distance very large, PoOC/CL 0.482. Scape short, SL/CS 0.741. Eye small, EYE 0.226. Occipital margin weakly concave. Anterior clypeal margin convex. Clypeus smooth. Frontal laminae and a small area caudal of them finely longitudinally carinulate. Dorsum of vertex, mesosoma, and waist in overall impression distinctly shining. Vertex with very shallow and small foveolae of 4 - 10 mm diameter; foveolar interspaces brilliantly shining and much wider than foveolar diameter, occasionally with fragments of a very fine perifoveolar microreticulum. Surface structure of dorsal promesonotum similar to vertex. Whole propodeum as well as meso- and metapleurae reticulate. Lateral area of pronotum smooth, finely microreticulate. Petiolar and postpetiolar nodes shining, with very fine microreticulum. Dorsum of gaster smooth and with fragments of very fine microreticulum. Petiole node in dorsal view almost globular, postpetiole with straight frontal margin and angulate-convex sides. Metanotal groove entirely absent. Spines shorter than in C. minutior, almost triangular. Microsetae on eyes sparser and shorter than in C. minutior. Pubescence on whole body shorter and less dense than in C. minutior, sqrtPDG 4.25. Petiole in profile with concave anterior face and rounded node. Postpetiole very low, its stemite very flat, without any prominent structures. Antennal club, gaster, propodeum, meta- and mesopleurae dark to blackish brown. Vertex, promesonotum, waist, and appendages light-yellowish brown.

Type Material
England: West Didsbury near Liverpool [type investigated]. 1 type worker labelled “Cardiocondyla britteni Crawley” and “West Didsbury 12-5-1919 B.h.H. Butter Beans”, Oxford.