Cardiocondyla nana Seifert 2003

Seifert, Bernhard, 2024, A taxonomic revision of the ants of the Cardiocondyla wroughtonii group (Hymenoptera: Formicidae) with a checklist of the Cardiocondyla species of the world, Soil Organisms (London, England) 96 (2), pp. 113-144 : 133

Cardiocondyla nana Seifert 2003 [type investigation]

This taxon has been described from Brunei. Investigated was the holotype worker labelled ‘ BRUNEI: Ulu Temburong L.P.-283.m. T. 22.ii.82. MC. Day’ , depository BMNH London .

All material examined. Only the type specimen is known.

Geographic range. The type locality is situated at 1.47°S, 123.559°E and 12 m a.s.l.

Diagnosis: --Worker ( Tab. 1, Figs16–18, key).Extremely small, CS 366 µm. Head extremely short, CL/CW 1.069. Median third of anterior clypeal margin deeply, median third of occipital margin slightly concave. Postocular distance large, PoOc/CL 0.464. Frons moderately broad (FRS/CS 0.266), frontal carinae diverging caudad. Eye without any microsetae and small, EYE/CS 0.220. Scape rather long, SL/CS 0.818. Metanotal groove in lateral view relatively deep (MGr/CS 2.50 %). Propodeal spines long and thin, rather steep, in profile deviating from longitudinal mesosomal axis by 43° (SP/CS 0.192), in dorsal view strongly diverging and their bases moderately wide (SPBA/ CS 0.277). Petiole rather narrow and moderately high (PeW/CS 0.264, PeH/CS 0.336); in profile with almost linear (only slightly concave) anterior face and semicircular dorsum; in dorsal view with rather slender peduncle and almost globular node, which is slightly longer than wide. Postpetiole moderately wide and low (PpW/CS 0.426, PpH/CS 0.289); the sternite anterolaterally with a rounded lobiform protrusion on each side which clearly elevates above the level of median surface of sternite; the surface of the sternite thus appearing deeply concave in frontal view. Postpetiole in dorsal view with a concave anterior margin and convex sides. Anterior clypeus smooth, not shining. Frontal laminae and anteromedian vertex with weak microsculpture, consisting of an irregular mixture of corrugated, foveolate, and carinulate elements. Paramedian and lateral areas of vertex with a unique sculpture: densely-arranged, deeply impressed, flat-bottomed and very large foveae of 19–23 µm diameter. The largest foveolae show a well-demarcated central ring of 8–9 µm diameter which is connected with the outer ring through 2–4 very fine microcarinulae in 90° cross-wire arrangement, such suggesting a four-leaf clover; in the smaller foveolae the number of microcarinulae may be reduced. Whole lateral area of mesosoma, anterior area of pronotum, and dorsal area of propodeum strongly microreticulate; dorsal area of promesonotum similarly foveate as paramedian vertex. Longitudinal sculpture on whole mesosoma, including metapleural gland bulla, completely absent. Petiole strongly microreticulate, postpetiole shining, very finely microreticulate. Pubescence on first gaster tergite moderately long and very dilute (PLG/CS 6.29 %, sqPDG 5.60). All body parts light-yellowish.

Taxonomic comments. This species is not to confuse due to extremely small size, the extremely low CL/CW and the large characteristic foveolae on vertex.

Biology. Unknown.