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

The efficacy of morphometric characters for separating the species of the g enus Aspidiotes Schoenherr, 1847, was evaluated. Thirty characters were ana lyzed. Multivariate and univariate analyses of variance, and discriminant f unction analysis, all dem onstrated that each species is morphometrically d istinguishable. The lengths of rostrum, scape, onychium, pronotum, and widt h and length of elytra have the maximum discriminatory power. Males and fem ales are also morphometrically distinguishable, mainly due to differences i n the widths of rostrum between pterigia and at base of pronotum, and width and length of elytra. The classification functions provided by discriminan t gave the correct identification of every single specimen by sex and speci es. Mahalanobis' distances between species were calculated and subjected to UPGMA clustering, to construct a dendrogram reflecting the morphometric re lationships between species. This dendrogram did not correspond to the phyl ogenetic relationships depicted by a cladogram based on discrete characters (Sanchez-Ruiz & Alonso-Zarazaga, 1994). Some hypotheses are reviewed, whic h might explain this discrepancy.