Describing selected populations of the rice black bugs in the Philippines using Correlation Analysis Based on Distances (CORIANDIS)

Abstract

Morphological shape variations of biological structures have been considered an important factor that affects the survival pattern of an organism. This study focuses to gain information on intraspecific variation among different populations of the rice black bugs (RBBs) using Correlation Analysis Based on Distances (CORIANDIS) from the generated relative warp scores of landmark-based geometric morphometrics. Results revealed that the shapes of genital plates have largely contributed a high observable disparity in all morphological characters. The shapes of the head and forewings also contributed noticeable variations while minimal variances were observed in the shapes of the scutellum and pronotum, respectively. The species/group projected plot among populations are clustered together except Bohol and Leyte populations which show a departure from other populations based from the centroid in the compromise space. The quality of the compromise is 52.99% for males and 51.40% for females. It was noticeable that the trait variance is unproportioned to the area occupied by datasets indicating population differentiation from other populations. These results indicate that geographic variations among populations of RBBs were contributed by high species’ divergence of the combined characters. This study suggests that CORIANDIS is a useful tool in describing population variability as this has the capacity to integrate all available morphological characters of populations to be able to visualize the underlying relationships among populations.

Keywords

• geometric morphometrics
• phenotypic plasticity
• species divergence
• CORIANDIS
• centroid