Abstract
We revise the species-level taxonomy of the Crematogaster (Crematogaster) degeeri-species-assemblage, a group of related ants occuring in Madagascar and the wider Malagasy region, and further provide an identification key to all species-groups of the genus Crematogaster in this region. Within the C. degeeri-assemblage, we recognize twelve species based upon morphological data from worker, queen and male ants, as well as genetic data from the barcode region of cytochrome oxidase I. Seven new species are described: Crematogaster alafara Blaimer sp. nov., C. bara Blaimer sp. nov., C. mafybe Blaimer sp. nov., C. maina Blaimer sp. nov., C. malahelo Blaimer sp. nov., C. masokely Blaimer sp. nov., C. ramamy Blaimer sp. nov. Crematogaster tricolor Gerstäcker, 1859 (stat. rev.) and C. dentata Dalla Torre, 1893 (stat. nov.) are raised to species level, and the following new synonymies are proposed: Crematogaster degeeri lunaris Santschi, 1928 as a synonym of C. degeeri Forel, 1886; Crematogaster sewelli improba Forel, 1907 and C. sewelli mauritiana Forel, 1907 as synonyms of C. dentata Dalla Torre, 1893, and C. pacifica Santschi, 1919 as a synonym of C. lobata Emery, 1895. Species descriptions, images, and distribution maps and identification keys based on worker ants, as well as on queen ants where available, are presented for all twelve species. In addition, we present a molecular gene tree for cytochrome oxidase I and summarize levels of sequence divergence within and between species of the C. degeeri-species-assemblage. Our findings are discussed in the light of previous work on Malagasy Crematogaster ants.
Highlights
Crematogaster Lund, 1831 ants are a species-rich clade commonly known as “acrobat ants”
Except for four cases (C. dentata Dalla Torre, 1893 stat. nov., C. maina sp. nov., C. degeeri Forel, 1886, C. ramamy sp. nov.), we found good evidence for our putative species, and phylogenetic support values ranged from posterior probabilities = 1 and bootstraps between 73-100 (Fig. 1)
We have presented a revision of the C. degeeri-species-assemblage based on morphological and molecular data, and describe and re-describe a total of 12 species, seven of which are new to science
Summary
Crematogaster Lund, 1831 ants are a species-rich clade commonly known as “acrobat ants”. This group currently includes more than 460 existing nominal species names (Blaimer 2012d; Bolton 2012) and is distributed worldwide. High intraspecific morphological variation renders the species-level taxonomy of acrobat ants challenging (Blaimer 2010, 2012a, Blaimer & Fisher 2013). Is further complicated by many synonyms and intraspecific names (Brown 1973). Blaimer 2010, 2012c; Hosoishi & Ogata 2009, 2012; Longino 2003, Blaimer & Fisher 2013). Nomenclatural problems make identification of the Afrotropical Crematogaster fauna unmanageable, and much of the diversity of these ants in this region probably has not yet been revealed
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