Emeryia, Xenometra, zoserka: it's a boy, again! The misleading morphology of Cardiocondyla male ants

  • J. HeinzeEmail author
Research Article


Wingless “ergatoid” males of the ant genus Cardiocondyla have repeatedly been described as females of novel genera of workerless social parasites (Emeryia and Xenometra), which after recognition of their real nature were synonymized with Cardiocondyla. Examination of ants newly collected from Comoé National Park in Côte d’Ivoire, West Africa revealed that winged Cardiocondyla males have sparked a similar misidentification: the “winged female sexuals” of the supposed inquiline Cardiocondyla zoserka Bolton 1982, known only from the type material from Nigeria, are in fact the winged males of their presumed host, a species of the Cardiocondyla shuckardi group (sensu Seifert 2002). The types of C. zoserka are immediately recognizable by their strangely modified antennal funiculi with cup-shaped apical segments, which do not resemble any other known ant antenna. More than twenty winged individuals from two Cardiocondyla colonies from the flood plain of Comoé River exhibited the same strange modifications of their antennae and were otherwise also similar to the C. zoserka type specimens. However, these winged ants turned out to be winged males rather than winged female sexuals. The inspection of the holotype and one paratype of C. zoserka verified that they also were males: like the winged males from Comoé N.P., they have concealed male genitals and ocelli, which are considerably larger than those of the female sexuals of Cardiocondyla. All female sexuals and workers found in the colonies with the bizarre winged males from Comoé N.P. had antennae with a three-segmented club as is typical for this genus. Sequences of the mitochondrial cytochrome c oxidase subunits I (CO I) and II (CO II) of a winged male and two nestmate workers showed that they are close to C. venustula and C. shuckardi but differ from them in about 10% of the base pairs. Other samples of Cardiocondyla collected in Comoé N.P. belong to C. venustula and related species. Their males were always ergatoid or “intermorphic” (i.e., ergatoid with rudimentary wings), as previously found in other populations of C. venustula, and never winged with modified antennae.


Ant males Ergatoid males Inquilinism Social parasitism Cardiocondyla 



Research in Comoé Park was permitted by the director of the Office Ivorien des Parcs et Réserves (permit no. 221), the exportation of ants by a permit from the Ministère de l’ Enseignement Supèrieur et de la Recherche Scientifique. I thank Dr. Koné N’golo Abdoulaye, Dr. Erik Frank, and the staff of the Comoé Research Station for their help with obtaining permits and technical support. Claudia Gstöttl and Tina Wanke helped locating and excavating the colonies of Cardiocondyla. Tina Wanke and Birgit Lautenschläger assisted with Keyence and SEM photography and Andi Trindl and Nana Gratiashvili with DNA isolation and amplification. I thank Stefan Cover and Bernhard Seifert for their opinions about the type material of C. zoserka and Suzanne Ryder for providing the paratype from BMNH. The research was supported by Deutsche Forschungsgemeinschaft (He1623/42).

Supplementary material

40_2019_737_MOESM1_ESM.pdf (934 kb)
Supplementary material 1 Figure S1 Bootstrap consensus tree of 814 bp fragments of the mitochondrial CO I gene from various samples of Cardiocondyla ants, inferred using the neighbor-joining method. Taxa representing species of the C. shuckardi group are shown in red (C. shuckardi from Madagascar) or black (C. venustula), the samples from Comoé National Park resembling C. zoserka are shown in green. Sequences of other species, e.g., C. emeryi, C. mauritanica, and C. nuda were added as outgroups in blue. The figures next to the branches indicate the percentage of replicate trees in which the associated taxa clustered together in the bootstrap test (500 replicates). Branches with a support of less than 60% were collapsed. For each sample, collecting site, and number, ISO country code (AU: Australia; CI: Côte d’Ivoire; EG: Egypt; ET: Ethiopia; FR: France; ID: Indonesia; KE: Kenya; MG: Madagascar; PR: Puerto Rico; PT: Portugal, US: USA; ZA: South Africa) and, if available, GenBank accession numbers are given. The tree only illustrates the identity of the sequences of a winged male, two nestmate workers and a worker from a second colony of the taxon from Côte d’Ivoire similar to C. zoserka and their difference from C. venustula/C. shuckardi. It is not meant to draw conclusions about the phylogeny of the various taxa. Samples with the collecting site “Comoé” are from the floodplain of Comoé River (8° 46′ 25′′ N, 3° 47′ 03′′ W). The collecting site “Comoé Gawi” is at 9° 00′ 19′′ N, 3° 47′ 53′′ W, “Comoé Iringo” at 8° 50′ 25′′ N, 3° 46′ 15′′ W, “Comoé Kongo River” at 8° 48′ 04′′ N, 3° 46′ 19′′ W, “Comoé Namba” at 8° 47′ 03′′ N, 3° 48′ 12′′ W, and “Comoé Res. Station” at 8° 46′ 14′′ N, 3° 47′ 23′′ W (PDF 934 kb).


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Copyright information

© International Union for the Study of Social Insects (IUSSI) 2019

Authors and Affiliations

  1. 1.Zoology/Evolutionary BiologyUniversity of RegensburgRegensburgGermany

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