Thirty colonies of the Marsh Fritillary (Euphydryas aurinia) have recently been recorded in Western Bohemia, Czech Republic. The majority of colonies are small, their total area are 1.5 km2. Small size and intensive grazing/mowing were positively associated with observed declines/extinctions, while abandonment threatens the colonies in the longer term. Short distances to nearest colonies buffered against declines. High colony turnover, asynchronous local dynamics pointed and the species’ biotope requirements all point to a dynamic metapopulation structure; patterns of connectivity revealed that there are several metapopulations within the region. Because conserving the species within its extant sites seems unsustainable in the long term, restoration of its habitats is proposed.

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Abstract. The butterfly Proclossiana eunomia (Lepidoptera: Nymphalidae) was discovered at a single locality in the Czech Republic in 1963. Until the 1980s, it was known from a restricted area, from which it spontaneously expanded during the 1980s to other localities up to 23 km from the source population. Samples were collected in 2002 from the source and ten other populations, totalling 274 specimens. All samples were analysed by electrophoresis for four polymorphic loci. Mean heterozygosity decreased with distance from the source population; this suggested a process of stepping stone colonization, involving the loss of rare alleles along the way. The populations close to the source population (less then ca. 15 km) retain a similar heterozygosity, whereas populations further away have a much reduced heterozygosity. Such a pattern of genetic differentiation and founder effect within a region is typical of specialized species with relatively low dispersal ability. The high level of genetic polymorphism found in the Šumava populations suggests that populations of this northern species in temperate-zone mountains are not just outposts of otherwise huge northern distribution, but represent genuine phylogeographic refugia. Survival of such species depends on the survival of the source population and of a sufficiently dense network of habitat patches.

A highly isolated and the last autochthonous Czech Republic population of the endangered Euphydryas maturna (Lepidoptera: Nymphalidae) is monitored since 2001 by larval nests counts. The 20 years` time series displays remarkable abundance fluctuations with peak-to-peak period 11 years, peak numbers >150 and bust numbers <15 larval nests (arithmetic and harmonic means: 92.6 and 36.3). Establishment of more favourable management of the site probably heightened and prolonged the boom phase but did not alter the overall pattern. We attribute the cycling to pressures of natural enemies. Climatically unfavourable years appear deepening the bust phase. Species displaying such fluctuations cannot be conserved within a single site, which is being addressed by ex-situ breeding of the Czech stock and recent reestablishment of two additional populations, with the aim to achieve asynchronous dynamics of the local populations and eventually stabilise the regional metapopulation.