| 1. |
- Cassel-Lundhagen, Anna, et al.
(author)
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Effects of patch characteristics and isolation on relative abundance of the scarce heath butterfly Coenonympha hero (Nymphalidae)
- 2008
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In: Journal of Insect Conservation. - : Springer Science and Business Media LLC. - 1366-638X .- 1572-9753. ; 12:5, s. 477-482
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Journal article (peer-reviewed)abstract
- The scarce heath (Coenonympha hero) is an internationally threatened butterfly in Western Europe, where it occurs primarily on hay fields and abandoned arable land in a small-scale agricultural landscape of south-central Scandinavia. Due to afforestation, this habitat is becoming increasingly fragmented in Sweden, and it can be expected that the scarce heath will decline abruptly when threshold conditions for metapopulation persistence are no longer met. We used stepwise polychotomous logistic regression to compare habitat characteristics and isolation measures for patches that harbour large, small or no populations, respectively, in an area of south-western Sweden. We found that patch area, distance to the nearest large population and amount of Galium spp. explained a significant part of the variation in relative abundance among patches. Distance to nearest large population resulted in a better model to predict occupancy than both distance to the nearest inhabited patch and connectivity, which suggests that primarily large populations act as sources for small satellite populations. Today, sites of three of the eight larger populations in the study area have been planted with spruce or pine and will disappear within 20 years. We argue that the disappearance of these patches may very well lead to rapid extinction of the whole metapopulation system.
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| 2. |
- Cassel-Lundhagen, Anna, et al.
(author)
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Limited dispersal by the rare scarce heath butterfly - potential consequences for population persistence
- 2007
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In: Journal of Insect Conservation. - : Springer Science and Business Media LLC. - 1366-638X .- 1572-9753. ; 11:2, s. 113-121
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Journal article (peer-reviewed)abstract
- Dispersal between habitat patches may be important for the long-term persistence of populations. We conducted a mark-release-recapture study and analysed the dispersal pattern in the scarce heath butterfly inhabiting a network of suitable habitat patches using stepwise logistic regression (SLR) and the Virtual Migration (VM) model. We also analysed the influence of different types of matrices. We found that the majority of the recaptured butterflies remained within the patch where they were originally caught. However, dispersal between patches did occur and both the SLR analysis and the VM model indicated that the migration pattern was significantly associated with patch area and its level of isolation. The SLR model also showed that there was a positive association between immigration rate and tree density, supporting earlier observations that this species prefers semi-open habitat. We discuss the use of SLR versus the VM model to analyse recapture data in dispersal studies. This system is not at equilibrium, as a number of the most important patches in the network are continuously being lost due to afforestation and a number of populations are facing deterministic extinction. This increases the risk of a chain reaction of local extinctions, which may cause a collapse of the whole system.
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| 3. |
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| 4. |
- Lundhagen, Anna, et al.
(author)
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Are peripheral populations special? Congruent patterns in two butterfly species
- 2009
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In: Ecography. - Malden : Wiley-Blackwell. - 0906-7590 .- 1600-0587. ; 32:4, s. 591-600
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Journal article (peer-reviewed)abstract
- Populations at range margins may be genetically different from more central ones for a number of mutually non-exclusive reasons. Specific selection pressures may operate in environments that are more marginal for the species. Genetic drift may also have a strong effect in these populations if they are small, isolated and/or have experienced significant bottlenecks during the colonisation phase. The question if peripheral populations are special, and if yes then how and why, is of obvious relevance for speciation theory, as well as for conservation biology. To evaluate the uniqueness of populations at range margins and the influence of gene flow and selection, we performed a morphometric study of two grassland butterfly species: Coenonympha arcania and C. hero (Lepidoptera: Nymphalidae). The samples were collected from Swedish populations that are peripheral and isolated from the main area of the species distributions and from populations in the Baltic states that are peripheral but connected to the main area of the species distributions. These samples were compared to those from central parts of the species distributions. The isolated populations in both species differed consistently from both peripheral and central populations in their wing size and shape. We interpret this as a result of selection caused by differences in population structure in these isolated locations, presumably favoring different dispersal propensity of these butterflies. Alternative explanations based on colonisation history, latitudinal effects, inbreeding or phenotypic plasticity appear less plausible. As a contrast, the much weaker and seemingly random among-region differences in wing patterns are more likely to be ascribed to weaker selection pressures allowing genetic drift to be influential. In conclusion, both morphological data and results from neutral genetic markers in earlier studies of the same system provide congruent evidence of both adaptation and genetic drift in the isolated Swedish populations of both species.
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| 5. |
- Lundhagen, Anna, et al.
(author)
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Characterization and cross-amplification of 13 microsatellite loci in the northern pine processionary moth, Thaumetopoea pinivora (Lepidoptera: Notodontidae)
- 2009
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In: Molecular Ecology Resources. - : Wiley. - 1755-098X .- 1755-0998. ; 9, s. 1074-1075
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Journal article (peer-reviewed)abstract
- Thirteen polymorphic microsatellite loci were developed for the northern pine processionary moth (Thaumetopoea pinivora) and tested for cross-amplification in seven other species within the Thaumetopoea family. Number of alleles ranged from two to 10 when at least 28 individuals from one population were screened and one locus, Thapin06, appears to be sex linked. Expected heterozygosity ranged from 0.094 to 0.856 and observed heterozygosity ranged from 0.097 to 0.806. Amplification success varied between sister species, with two up to seven loci being successfully amplified. The described loci will be valuable for studying the population genetic structure and dispersal behaviour of this forest pest.
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| 6. |
- Lundhagen, Anna, et al.
(author)
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Species-specific primers for predation studies of the pollen beetle, Meligethes aeneus (Coleoptera, Nitidulidae)
- 2009
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In: Molecular Ecology Resources. - : Wiley. - 1755-098X .- 1755-0998. ; 9, s. 1132-1134
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Journal article (peer-reviewed)abstract
- Species-specific primers were developed for the pollen beetle (a pest in oilseed rape) for studies of predation by natural insect predators. Two forward and three reverse primers were designed within the mitochondrial COI gene and used in combination to amplify fragments in the size range of 163-290 bp. Remains of pollen beetle DNA were consistently detected in Pardosa spiders up to 24 h after ingestion but dropped drastically at 48 h. These primers will facilitate studies on biological control of this oilseed rape pest. Detection time was not correlated with fragment length as might be expected as the DNA gradually degrades into progressively shorter fragments over time.
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