Geographic variation of wing morphology in three Eurasian populations of the fruit fly, Drosophila lummei

Differences in wing morphology are described for three Eurasian populations of Drosophila lummei. A truss network of wing characters was used to quantify wing size and shape for 149 individuals from Japan, Sweden and Russia. Sexual dimorphism in wing size and shape was not substantial, so the sexes were pooled and multivariate analyses conducted. Both principal components analysis and discriminant analysis of wing morphology revealed significant differences among all geographic groups. These differences indicate that morphometric analysis of wing characters can reliably discriminate between geographic groups and accurately classify individuals of the three Drosophila lummei populations. Principal components analysis also revealed that characters occurring in the same section of the wing formed correlated suites which corresponded to morphologically and functionally distinct areas of the wing. This study is unique because it detects subtle morphological differences within a single species of fruit fly across an intercontinental distribution. The results corroborate genetic studies in which geographic variation was found for inversion polymorphisms among spatially separated populations of Drosophila lummei.