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The damselfly Coenagrion ornatum is a threatened species, specialized for lowland headwater streams. As the species is declining and protected across Europe, it represents a species of particular conservation interest. This work aims to provide the first evaluation of fine-scale spatial ecology in this species, especially to assess its general mobility and distribution of adults in relation to larval habitats, and to suggest implications for conservation and efficient monitoring of this species. Adults were captured-recaptured along four distinct streams (5.2 km together) in the Radovesická spoil heap, Czech Republic. Immature adults and breeding individuals were recorded simultaneously. Larvae were sampled in 64 sections of 27 m, evenly distributed across the studied streams. In total, 1152 adult individuals were marked; from these, 240 individuals were recaptured at least once. Larvae were detected in 21 sites with a total number of 61 individuals. The adults were highly sedentary, with a median lifetime dispersal of 11 m. Only one male was reported to move between two distinct streams. Model comparisons revealed that female and breeding pair abundances are a significantly more reliable indicator of larval abundance than male and total adult abundances, especially when used along with records of the immature adults. Moreover, the weighted least square models showed that the female abundances are spatially more specific (i.e., less autocorrelated) than male abundances. These results imply that surveying the adult females, along with the breeding and immature adults, offers the best method for local habitat quality assessment for this Natura 2000 species. [ABSTRACT FROM AUTHOR]

The phylogeographic structures of taiga species often support the hypothesis of East Palaearctic refugia for these taxa, but the phylogeographic structures of northern temperate and southern boreal bog species are still poorly understood. Therefore, we analysed the genetic diversity and differentiation of a stenotopic damselfly, Nehalennia speciosa, across its trans-Palaearctic range by means of sequencing two mitochondrial gene fragments, 16S rRNA-ND1 and cytochrome c oxidase II. Only four single nucleotide polymorphisms were detected over the 1130 sequenced nucleotides. This low genetic diversity and differentiation and thus the lack of phylogeographic structure imply postglacial expansion from a single Würm Ice Age refugium, most likely located in the Far East of Asia, i.e. Manchurian refugium. From here, the species could have colonized large parts of the Palaearctics, including Europe, during the postglacial. [ABSTRACT FROM AUTHOR]

Oligo- and mesotrophic wetlands, such as bogs, fens and swamps, have become more and more restricted in Europe, and wetland species related to them have increasingly been threatened. Due to increasing habitat fragmentation, the exchange of individuals of these species among sites and, as a consequence, gene flow has been reduced or even eliminated. Therefore, we analysed the genetic structure of 11 populations of an endangered stenotopic damselfly, Nehalennia speciosa (Odonata: Coenagrionidae), in Poland and Lithuania by means of allozyme electrophoresis of 14 gene loci. The overall genetic diversity of all populations was low (A: 1.32; H: 2.6%; Ptot: 29.2%), and no significant differences were observed among the different groupings of populations (degree of fragmentation, habitat type and size, population size). The genetic differentiation among populations was also low (FST: 2.0%) and no regional groups were detected. A low degree of isolation by distance was observed for genetic distances. Taking into account these results, the conservation effort for this species should be focused on large local populations and not necessarily on metapopulation structures. Furthermore, N. speciosa could be (re-)introduced in extinct patches and seemingly suitable localities. Genetically, such relocations should be feasible due to the generally high genetic homogeneity of populations. [ABSTRACT FROM AUTHOR]

1. Coenagrion mercuriale is one of Europe's rarest and most threatened damselflies. It is listed in the European Community (EC) Habitats and Species Directive and is the only odonate currently given priority status in the UK Biodiversity Action Plan. Information regarding patterns of movement and dispersal in this species is required to guide conservation and management programmes. Management is currently geared towards habitat restoration of isolated subpopulations, with little attention paid to the metapopulation and landscape context. 2. A multisite mark–release–recapture project was carried out in the valley of the River Itchen in southern England to determine the extent of movement and the factors affecting movement of mature adults of this endangered damselfly. A total of 8708 individuals was marked. 3. The species was found to be extremely sedentary, with dispersal limited to an area of contiguous habitat. The median net lifetime movement was 31·9 m and 66% of individuals moved less than 50 m in their lifetime. Movements of greater than 500 m were rare and the longest recorded movement was 1·79 km. This makes it the most sedentary odonate that has been studied in the UK. 4. The highest recapture rates and the lowest movement distances were recorded at the most isolated site. Time between capture and recapture, and day in season had an effect on movement, and individuals travelled further on their first than on subsequent moves. There was no consistent effect of age or sex on distance moved. 5. There was strong evidence for inverse density-dependent movement, with individuals moving further in low-density than high-density populations. This is the first time that inverse density-dependent movement has, to our knowledge, been observed in a natural population of odonates. 6. Synthesis and applications. Coenagrion mercuriale, along with many other invertebrate species of conservation concern, lives in a management-dependent mid-successional habitat. However, the species is highly sedentary. Furthermore, patterns of movement and dispersal are strongly affected by landscape structure and population density. This means that it is unable to recolonize isolated sites and requires ‘stepping stone’ habitats to improve its chances of survival in the medium to long term. Suitable habitat management between sites that are beyond the dispersal distance of individuals can be used to connect or reconnect populations. Within existing sites only small sections of habitat should be managed in any one year and new areas should be created close to existing populations. The long-term persistence of C. mercuriale and other invertebrate species requires a landscape approach to management, with connectivity an important part of management planning. It is clear that carefully conducted studies of movement and dispersal are key components in guiding invertebrate conservation strategies. [ABSTRACT FROM AUTHOR]