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

Abstract

Mindanao. Moreover, it is argued that a successful control of the pest is based on correct identification for the inability to recognize distinct populations can have severe and costly consequences for pest management (3). There is, therefore, a need to consider the coconut hispine beetle (CHB) in details to stop its infestation in the country especially that different levels of infestation have been observed among the invaded localities. Morphological variability is a good start to better understand why the CHB have differed in the level of infestation, for distinct populations of agronomic pest differ only on little phenotypic characters and sometimes these may represent stable characters with genetic bases which are good bases for the study (4). This study applied the advanced tools of geometric morphometrics (GM) to be able to describe morphological diversity of B. longissima from different locations. Geometric morphometrics (GM) have the advantage to provide a consistent set of shape variables for hypothesis testing (5) and deliver the sound graphic analyses that quantify and visualize morphometric variation within and between organisms (6). This study uses outline-based GM analysis that extract the margin around the specimen and this is conducted to gain information on intraspecific variation of both female and male B. longissima that might explain its fitness. Since the last abdominal sternum of beetles is assosiated with a chitinous apodeme of variable shapes, (7) this study is therefore conducted in this structure to determine patterns of variation among populations of the coconut hispine beetle, B. longissima.