Taxonomic revision of the Malagasy group (Hymenoptera: Formicidae).

BACKGROUND

Madagascar is famous for its extremely rich biodiversity; the island harbors predominantly endemic and threatened communities meriting special attention from biodiversity scientists. Continuing ongoing efforts to inventory the Malagasy ant fauna, we revise the species currently placed in the myrmicine genus Mayr. One species described from Madagascar, Forel, is synonymized with the Palearctic Latreille This species is considered neither native to Madagascar nor established in the region. This revision focuses on the balance of species in the group which are all endemic to Madagascar.

METHODS

The diversity of the Malagasy fauna was assessed via application of multiple lines of evidence involving quantitative morphometric, qualitative morphological, and DNA sequence data. (1) Morphometric investigation was based on hypothesis-free (NC-clustering) combined with (PART) to estimate the number of morphological clusters and determine the most probable boundaries between them. This protocol provides a repeatable and testable approach to find patterns in continuous morphometric data. Species boundaries and the reliability of morphological clusters recognized by these exploratory analyses were tested via confirmatory Linear Discriminant Analysis (LDA). (2) Qualitative, external morphological characteristics (e.g., shape, coloration patterns, setae number) were subjectively evaluated in order to create a priori grouping hypotheses, and confirm and improve species delimitation. (3) Species delimitation analyses based on mitochondrial DNA sequences from cytochrome oxidase I (COI) gene fragments were carried out to test the putative species previously delimited by morphological and morphometric analyses.

RESULTS

Five species can be inferred based on the integrated evaluation of multiple lines of evidence; of these, three are new to science: ., (Emery, 1899), , , and Forel, 1886. In addition, three new synonymies were found for Forel, 1886 ( Santschi, 1915 , Forel, 1891 and Santschi, 1911 ). Descriptions and redefinitions for each taxon and an identification key for their worker castes using qualitative traits and morphometric data are given. Geographic maps depicting species distributions and biological information regarding nesting habits for the species are also provided.