Landmark- and Semi-Landmark-Based Geometric Morphometrics as a Tool for the Identification of Genera of Seed Beetles (Coleoptera: Chrysomelidae: Bruchinae)

We conducted a study to evaluate the utility of geometric morphometrics (GMM) using landmarks and semi-landmarks of the wings of beetles in the subfamily Bruchinae, focusing on a diversity of genera and including those most likely to be intercepted in agricultural shipments. Our results show promise for the value of hind wing landmarks (mostly veins and vein intersections) as well as semi-landmarks of the elytra (contour, shape). Geometric morphometric analysis of the landmarks of the hind wings and semi-landmarks of the elytra show differences in shape among the sampled genera of beetles. Principal component analysis demonstrated that the hind wing shapes of the males from different genera were distinctive in the morphospace, and discriminant function and canonical variate analyses showed differences in the shapes of the hind wings and elytra between the different genera, particularly between the genus Acanthoscelides Schilsky and the other genera. The results of our study show the potential of GMM for the identification of hard-to-identify taxa based on traditional taxonomy (external morphology), in particular on morphologically conservative taxa, species complexes, or taxa that are similar due to convergence.