Title |
Quantitative Description of the Scutellum of Rice Black Bugs in the Philippines using Landmark-based Geometric Morphometrics |
Authors |
Melbert C. Sepe, Mark Anthony J. Torres, Ravindra C. Joshi, Cesar G. Demayo |
Publication date |
2019 |
Journal |
Ciencia |
Volume |
38 |
Pages |
1-15 |
Publisher |
Western Mindanao State University |
Abstract |
Among the pests encountered in the rice fields, rice black bug or RBB are the most predominantly invasive and highly unfamiliar pests in the Philippines. Since RBB outbreaks vary from location to location, the study focuses on the use of landmark-based geometric morphometrics to quantify and determine shape variations of RBB scutellum between sexes and within-group populations. Results revealed that the shape of scutellum may either have inward lateral sides with pointed posterior margin or outward lateral sides with rounded posterior margin. Most likely, male RBB are narrower and pointed, compared to the slender and rounded scutellum of female RBB. Noticeably, high intrapopulation variation was observed in both allmale and all-female RBB populations. The results also affirm the pairwise comparison of population-to-population, indicating significant scutellum shape variations within-group comparisons. The results imply that the differences might be associated to phenotypic plasticity. The tool of geometric morphometrics is helpful in quantitatively assessing the variations of morphological characters in organisms and for understanding the patterns of variability between populations. Further studies on genetic basis are deemed necessary |
Index terms / Keywords |
Geometric morphometrics, Procrustes superimposition, RBB, Relative warp, Scutellum, Thin-plate spline |
URL |
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