Taxonomic revision of the Malagasy Camponotus grandidieri and niveosetosus species groups (Hymenoptera, Formicidae) using qualitative and quantitative morphology

The Camponotus grandidieri species group and Camponotus niveosetosus species group of the Malagasy region are revised. Species delimitation was inferred from the evidence of both qualitative morphological analysis and multivariate morphometry. The multivariate method combined the Nest Centroid (NC)-clustering method and Partitioning Algorithm based on Recursive Thresholding (PART) function to generate hypotheses about species boundaries (clusters) based on 19 continuous morphological traits of minor workers. The proposed species hypotheses were tested by cumulative cross-validated Linear Discriminant Analysis (LOOCV-LDA) and Principal Component Analysis in a shape space (shape PCA). Morphometric ratios for the subsets of minor and major workers were used in species descriptions and redefinitions. Here, eight species are recognized, of which three are newly described and five are redescribed. Four species belong to the Camponotus grandidieri species group: auropubens Forel, efitra n. sp....