Variability in the Last Abdominal Sternum of Brontispa longissima Populations Using Outline-Based Geometric Morphometric Analysis

The coconut plant plays a major role in the economy of many Asian countries including the Philippines and their economies are recently threatened due to a serious outbreak of the coconut leaf beetle, Brontispa longissima (Gestro). This study was conducted to observe if there is an intraspecific morphological variation among the coconut hispine beetle populations in terms of the last abdominal sternum shape to better understand why these pests differed in the level of their infestation in different populations. From outline-based geometric morphometrics analysis, results showed that a considerable sternum shape variation among the populations is studied. Morphological sternum shape variations were verified statistically in Principal Component Analysis, Canonical Variate Analysis, and Multivariate Analysis of Variance (MANOVA) using PAST 2.13 software. Furthermore, shape differences could be observed in the shape representation of Elliptic Fourier Shape analysis as well as in the PCA diagrams and CVA scatter plots.