ANALYSIS OF GENE FLOW AND HABITAT PATCH NETWORK FOR CHAZARA-BRISEIS (LEPIDOPTERA, SATYRIDAE) IN AN AGRICULTURAL LANDSCAPE

A fine geographic-scale population genetic structure analysis was perf ormed for the endangered butterfly species Chazara briseis in the regi on of Halle an der Saale, Germany, for the investigation of gene flow and possible effects of habitat fragmentation on genetic variability. Patterns of genetic Variance were estimated by allozyme electrophoresi s and quantified with F-statistics. Levels of genetic variation were h igh, expected heterozygosity H-e = 0.20, and mean number of alleles pe r locus, A = 1.93, indicating large population sizes. Butterflies inha biting the study area probably constituted just one population and the fragmented nature of the habitat patches did not substantially affect gene flow among sites. Sampling sites were isolated by distance due t o low median dispersal probabilities. This caused a micro-structure wi thin the population and indicated that habitat patches acted as linked units with no oriented dispersal preferences of C. briseis. (C) 1997 Elsevier Science Ltd.