Ant fauna (Hymenoptera: Formicidae) of the Socotra Archipelago (Yemen): zoogeography, distribution and description of a new species

ABSTRACT

The animal fauna of the Socotra Archipelago is influenced by three biogeographical regions, the Afrotropical, the Oriental and the Palaearctic. Consequently, the Archipelago shares faunal elements of these three regions in addition to unique endemic taxa. The ant fauna of Socotra Island was studied and is reviewed based on literature and newly collected material. In total, 28 species, belonging to 10 genera and four subfamilies, were collected from the main island. Eighteen of these (64%) are successful invasive species, seven are native (25%), and three are considered endemic (11%), Cardiocondyla longiceps Seifert, Monomorium elghazalyi sp. nov. and Monomorium nimihil Collingwood et al. Two genera are recorded for the first time from the island, Hypoponera Santschi, and Syllophopsis Santschi. Ten species are recorded for the first time, Cardiocondyla mauritanica Forel, Cardiocondyla minutior Forel, Monomorium atomum Forel, Monomorium dichroum Forel, Monomorium exiguum Forel, Pheidole pallidula (Nylander), Syllophopsis cryptobia (Santschi), Tetramorium pauper Forel, Tetramorium transformans Santschi and Hypoponera punctatissima (Roger). Ten invasive species are recorded from Socotra, reflecting human impacts on the Archipelago. These species are Tapinoma melanocephalum (Fabricius), Cardiocondyla emeryi Forel, Monomorium exiguum Forel, Pheidole indica Mayr, Syllophopsis cryptobia (Santschi), Tetramorium lanuginosum Mayr, Tetramorium simillimum (Smith), Tetramorium caldarium (Roger), Trichomyrmex destructor (Jerdon) and Trichomyrmex mayri (Forel). Our survey indicated a mixture of Afrotropical faunal elements (10 species, 36%), followed by cosmopolitan (nine species, 32%), Palaearctic (five species, 18%) and Oriental (four species, 14%) taxa. Two new synonyms of Monomorium exiguum Forel are proposed: Monomorium exiguum Forel = Monomorium baushare Collingwood & Agosti syn. nov. = Monomorium qarahe Collingwood & Agosti syn. nov. Tetramorium transformans Santschi is removed from synonymy with Tetramorium caldarium (Roger) and elevated to species rank. Ecological and biological notes for each species are given. Distribution maps for all species known from the Socotra Archipelago are provided.

http://zoobank/urn:lsid:zoobank.org:pub:89612083-9CE6-48E8-8975-1CE5334E098B

KEYWORDS:

• Zoogeography
• Afrotropical region
• key
• new synonymy
• invasive species
• endemic
• new records
• Arabian Peninsula

Acknowledgements

We are grateful to Barry Bolton and Boris Kondratieff for their review of a draft of the manuscript. Thanks go to Francisco Hita Garcia, Christiana Klingenberg, Mahmoud Abdel-Dayem, Antonius van Harten, Shehzad Salman and Mohammed Metwally for their much appreciated help. The authors are indebted to Zach Lieberman, Erin Prado, Will Ericson, Estella Ortega and Michele Esposito for photographing species. We thank Prof. Abdulaziz Al Qarni for his valuable assistance, without his support the field work could not have been completed.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Deanship of Scientific Research at King Saud University [RGP-1436-029].