Cardiocondyla bicolor Donisthorpe 1930

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 : 131-132

Cardiocondyla bicolor Donisthorpe 1930

[types investigated]

This taxon was described from Israel. Investigated was the worker holotype labelled ‘ Palestine: Drs. D.Scheinkin & J.Carmin B.M.1930-163\ On Ficus sycamore\ bicolor Donisthorpe \ Type « and one worker paratype labelled ‘ Palestine: Drs. D.Scheinkin & J.Carmin B.M.1930-163\ On Ficus sycamore\ bicolor Donis. \ Cotype’. Depository: BMNH London. The type sample is allocated to the C. obscurior cluster with p =0.9992 if run as wild-card in a LDA (see above).

All material examined. Numeric phenotypical data were available in 43 samples (35 nest samples and 9 single-specimen stray samples) with 93 workers. For details see supplementary information SI1, SI2. Excluding single-specimen samples with unclear separation from C. wroughtonii , this material originated from Brasil (3

samples), Bermuda (1), Ecuador (2), Germany (3), Hawaii (2), India (1), Israel (1), Japan (10), Micronesia (1), Puerto Rico (2), Seychelles (5) Singapore (1), Spain (5), USA (4)

Geographic range. As a tramp species of putatively Southeast Asian origin this species is, like wroughtonii , widely distributed over the tropical regions of the Old and New World. However, with exception of a finding from Singapore, there are no verified vouchers from the Indo- Malayan and Australasian regions where C. wroughtonii is dominant. It has also been found in buildings in the temperate zone ( Germany).

Diagnosis: --Worker ( Tab. 1, Figs 32–35, key). Very small and slightly larger than wroughtonii, CS 430 µm. Head short, CL/CW 1.111. Anterocentral clypeal margin straight or slightly notched; central occipital margin usually straight or with a very weak concavity. Postocular distance large, PoOc/CL 0.435. Frons broad (FRS/CS 0.268), frontal carinae caudal of FRS level parallel (FL/FR 1.011). Eye medium-sized, EYE/CS 0.229. Scape short and slightly longer than in wroughtonii, SL /CS 0.772. Metanotal groove in lateral view deep (MGr/CS 3.65 %) and usually with steep anterior and posterior slopes. Promesonotal plane in dorsal view without ‘shoulders’ due to a strongly convex frontal margin and rather straight lateral margins (Fig. 34). Propodeal spines shorter than in wroughtonii (SP/CS 0.185) and their bases less approached (SPBA/CS 0.292). Petiole wider and slightly higher than in wroughtonii (PeW/CS 0.292, PeH/CS 0.338), axis of petiolar peduncle in lateral aspect deviating by 30° from the longitudinal axis of the petiole node. Postpetiole wider and higher than in wroughtonii (PpW/ CS 0.459, PpH/CS 0.314), 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. Sculpture on head, mesosoma and waist similar to wroughtonii . Pubescence on first gaster tergite moderately long and dilute (PLG/CS 6.2 %, sqPDG 5.13). The dark color morph, which resembles the dark color morp of wroughtonii , is found in 98 % of the samples – one sample, possibly hybrids, showed a pattern similar to the light color morph of wroughtonii .

Taxonomic comments. The morphological separation from C. wroughtonii is described above.

Biology. In contrast to C. wroughtonii , C. obscurior was reported to nest in cavities of bushes and trees 2–5 m above the ground level; it was found in dead twigs of trees such as Erythrina variegata (Okinawa), in dwarf coconuts ( Brazil), galls of Acacia trees ( Brazil), between crippled-curled leaves of a Citrus tree ( Brasil), in a dead twig on a tree (Florida), on a Ficus tree ( Israel), in the gall of a Tamarix bush ( Israel), below the bark of strong trees (Tenerife) and in the cavity of a coconut high in the tree ( Zanzibar). Demography and behavior of nest populations as well as male polyphenism and behavior are the same as in C. wroughtoni ( Heinze 2017) . Errbii et al. (2021) have shown that populations of Cardiocondyla obscurior belong to two distinct lineages, a lineage so far only found in Latin America and a more cosmopolitan Old World lineage. A strong genetic differentiation of these lineages began latest 40,000 generations ago but introgression from the Old World lineage is a dominant source of genetic diversity in the Latin America lineage and is likely to contribute to the adaptive potential of the Latin America lineage. The lineages are infected by different Wolbachia strains, one causing cytoplasmic incompatibility ( Ün et al. 2021).