Relative warp analysis in determining sexual dimorphism of Rynchophorus ferrugineus in Malungon Sarangani Province, Phillipines

Many traditional ways were introduced in determining and differentiating sexes between male and female beetle. One of this is through physical differences of their snouts, but this kind of identification holds less scientific evidences. Hence, there is a need of more scientifically based approach and one application that demonstrates potential methods in this discipline is known as Geometric Morphometric. Through the use of such tool, the aim of determining the sexual dimorphism of coconut snout bettle Rynchophorous ferrugineus using the hind wings of the species would be possible. A total of 19 landmarks from images of 120 hind wings (30 left wings; 30 ringth wings of female and and another set of 30 left wings and 30 rigth wings for male) of R. ferrugineus were subjected to Relative Warp (RW) analysis and Discriminant Function Analysis (DFA). The results revealed that the RW of female are RW1 = 31.11%, RW2 = 17.88%, RW3 = 10.79%, RW4 = 8.01%, RW5 = 5.27%, RW6 = 5.04%, RW7 = 4.49% and for male are RW1 = 33.87%, RW2 = 17.15%, RW3 = 9.45%, RW4 = 7.77%, RW5 = 4.81% explaining more than 5% of the variance. These results imply that females present 82.45% wing shape variation whereas males only showed 73.05% of variation. However, statistical test prove that using DFA confirmed that there were no significant differences on the wings based on the shape variations. Thus, the hind wing shape does not contribute to the selection of gender of R. ferrugineus.