Morphological Variability of the Satyrid Butterflies, Aphantopus hyperantus and Erebia ligea (Lepidoptera, Satyridae) in Allopatric and Allochronous Micropopulations

摘要

Abstract The variability of morphological traits (the shape and size of the forewing and the location, number, and diameter of eyespots in the submarginal band of the wing pattern) was studied and analyzed in two species of Satyridae, Aphantopus hyperantus (Linnaeus, 1758) and Erebia ligea (Linnaeus, 1758), occurring sympatrically in Sverdlovsk Province, the Urals. It was originally supposed that micropopulations of the univoltine generalist species A. hyperantus would be weakly isolated and phenotypically homogeneous, since their habitats were positioned a small distance apart (about 10 km) within the same forested area and connected by a network of roads and glades serving as potential dispersal corridors; in contrast, micropopulations of the bicyclic specialist species E. ligea would be more strongly isolated and, accordingly, would have a higher level of phenotypic differentiation. The variability of morphological traits was analyzed by phenetic methods and also by traditional and geometric morphometrics. In both species, significant differences between micropopulations were found in the wing shape and size, as well as in the location and stability of eyespots in the wing pattern. As expected, temporal and spatial isolation of the micropopulations has led to differentiation in E. ligea. At the same time, the initial hypothesis of homogeneity of the A. hyperantus population in the studied territory was not confirmed. The latter case demonstrates that spatial isolation may be sufficient for differentiation in a species that is significantly sedentary and does not fully use the existing dispersal corridors.