Separation of Aspidiotes species using morphometric analysis (Coleoptera: Curculionidae)

Abstract

The efficacy of morphometric characters for separating the species of the genus Aspidiotes Schoenherr, 1847, was evaluated. Thirty characters were analyzed. Multivariate and univariate analyses of variance, and discriminant function analysis, all demonstrated that each species is morphometrically distinguishable. The lengths of rostrum, scape, onychium, pronotum, and width and length of elytra have the maximum discriminatory power. Males and females are also morphometrically distinguishable, mainly due to differences in the widths of rostrum between pterigia and at base of pronotum, and width and length of elytra. The classification functions provided by discriminant gave the correct identification of every single specimen by sex and species. Mahalanobis' distances between species were calculated and subjected to UPGMA clustering, to construct a dendrogram reflecting the morphometric relationships between species. This dendrogram did not correspond to the phylogenetic relationships depicted by a cladogram based on discrete characters (Sanchez-Ruiz and Alonso-Zarazaga, 1994). Some hypotheses are reviewed, which might explain this discrepancy.