Genetic structure of natural populations of Dryas iulia (Lepidoptera: Nymphalidae) revealed by enzyme polymorphism and mitochondrial DNA (mtDNA) restriction fragment length polymorphism (RFLP).

Dryas iulia appears to have undergone a mode of evolution different from that of other members of its subfamily (Heliconiinae). While other species constitute highly subdivided and inbred populations, those of D. iulia are thought to be large and uniform. Analyzing six samples from Southern Brazil (state of Rio Grande do Sul) in relation to three enzyme systems (EST, LAP, and PGM) and their mtDNA RFLP patterns, we found that they are very similar at the molecular level. The F statistics for enzyme polymorphism data revealed that inbreeding makes a great contribution to the population homozygosity, since FIS equals 0.1322 and FST equals 0.0023. Since the chi-square test showed that FST is not significant, we conclude that all localities belong to the same population. The mtDNA differentiation was about 12 times greater than for nuclear genes; FST was equivalent to 0.0265. We suggest that this difference is due to a higher dispersal of males, in relation to females.