Shape and Wing Size Symmetry in local populations of Aedes albopictus Skuse

Abstract

A study on wing symmetry in Aedes albopictus was done using SAGE (Symmetry and Asymmetry of Geometric Data) software. Fifteen pairs of the left and right wings from each of the sexes of the mosquitoes collected from three locations (coastal, poblacion and rural) of Cagayan de Oro city were mounted on glass slides, microphotographed, digitized and assigned with 20 landmarks with tps Dig software. Thin-plate spline images of the wings were pooled in tps files using tpsUtil and were landmarked and subjected in SAGE software, ver. 1.04 to detect the state of symmetry in the wings. Results showed that for shape symmetry, Procrustes ANOVA of data sets for both sexes showed highly significant left-right variations as shown by significant individual, sides, and individual x side’s effects. Fluctuating Asymmetry (FA) was detected in both coastal and urban populations in the female but not in the rural population which had significant Directional Asymmetry (DA). For the male populations, DA was detected in the coastal populations but not in the other two populations. The results for the wing size symmetry analysis showed that all populations exhibited FA. These results in Aedes albopictus clearly indicate that there was developmental instability in wing size but for the wing shape, the existence of directional asymmetry in two populations – the rural population of the female and coastal population for the male indicate that the variations in symmetry in the mosquito can have a genetic basis.