The fragmented population structure of the Sardinian chalk hill blue butterfly (Lepidoptera, Lycaenidae)

The endemic Sardinian chalk hill blue butterfly, Polyommatus coridon gennargenti, is considered vulnerable to extinction because of its low genetic variation and restricted distribution. The species also has a fragmented distribution, which follows the patchy distribution pattern of its larval host-plant. A preliminary investigation of the population structure of P. coridon gennargenti was carried out on a small network of four local populations by means of capture–recapture methods. Estimated population sizes and movement rates among the four adjacent local populations suggest that this taxon has a metapopulation structure composed of loosely connected small local populations. Natural fragmentation, isolation, and traditional land use contribute to the vulnerability of P. coridon gennargenti to extinction. Low effective population sizes and restricted movement between habitat patches lead to inbreeding and an increased vulnerability to extinction of this island population.     

Microdistribution of butterflies in a mosaic-like habitat: The role of nectar sources

The microdistribution of five butterfly species through their flying season was analyzed in a mosaic-like habitat, brought about by secondary succession In order to explain the patterns observed, activity patterns and the use and distribution of nectar sources were determined Emphasis was laid on the changing allocation of visits to flower species and changing abundances of flowers during the season The use of nectar sources was basically limited to three flower species, Centaurea scabiosa, C bracteata and Serratula tinctoria As a consequence, niche breadth values were generally low and niche overlaps generally high Some butterflies changed their patterns of flower visits during the season and therefore reduced niche overlap with the other butterfly species The microdistribution of Melanargia galathea, Lysandra condon, Ochlodes venatus and Lictoria achilleae was strongly influenced by the distribution of their preferred nectar sources as well as by areas generally rich in flowers Changing flower preferences of Melanargia galathea and Lysandra coridon males during the course of the season were also expressed by changes in the correlations between the distribution of these butterflies and their nectar plants The distribution of nectar sources was not found to be of importance for Coenonympha arcanta, a species which rarely visited flowers     

Descriptions of two new species of butterflies (Lepidoptera,Lycaenidae) from the South Sinai

Two new species of lycaenid butterflies, Strymonidia jebelia and Pseudophilotes sinaicus, are described from the high mountains of South Sinai. The foodplants and the eggs of both species are also described with notes on the habitats and adult behaviour. Their relationships with closely allied species and the possible evolutionary histories are discussed.     

Just beautiful?! What determines butterfly species for nature conservation

Prioritization is crucial in nature conservation, as land and financial resources are limited. Selection procedures must follow objective criteria, and not primarily subjective aspects, such as charisma. In this study, we assessed the level of charisma for all European butterflies. Based on these data, we analysed the charisma values of the species listed on the annexes of the EU Habitats Directive and of the species being of conservation priority according to criteria derived by three objective criteria: Species ecological specialisation, distribution, and threat. The mean level of charisma was higher for species of the EU Habitats Directive than for species of conservation priority and for not-listed species. Five of the twenty most charismatic species were also listed on the EU Habitats Directive, but none occurred on the list of species being of conservation priority. A trait space analysis revealed remarkable differences between the different species assortments: The species listed on the EU Habitats Directive covered a large trait space and included many species with high charismatic value, but low ecological and biogeographical relevance, while species of high conservation priority covered a restricted trait space and did not overlap with charismatic species. According to our findings, the selection of species for nature conservation still follows a mix of being aesthetic combined with some ecological criteria.

     

Assessing the ecological risk posed by a recently established invasive alien predator: <Emphasis Type="Italic">Harmonia axyridis</Emphasis> as a case study

Invasive alien predators are a serious threat to biodiversity worldwide. However, there is no generic method for assessing which local species are most at risk following the invasion of a new predator. The harlequin ladybird, Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae), is an alien in Europe and many other parts of the world where it affects other species of ladybirds through competition for food and intra-guild predation (IGP). Here, we describe a method developed to assess which European ladybird species are most at risk following the invasion of H. axyridis. The three components of the risk assessment are: the likelihood that the assessed native species encounters H. axyridis in the field, the hazard of competition for food, and the IGP hazard. Thirty native European ladybird species were assessed through data obtained from field observations, laboratory experiments and literature reviews. The species that are considered most at risk are found on deciduous trees, have immature stages which are highly vulnerable to IGP by H. axyridis, and are primarily aphidophagous. These species should be the focus of specific studies and possibly conservation actions. The risk assessment method proposed here could be applied to other alien predators which are considered a threat to native species through competition and predation.     

Relationship between geographic rarity and perception of threat in Iberian butterflies

Measuring threat and selecting ??flagship?? species for conservation planning should ideally rely on ??dynamic?? criteria (i.e.: decreasing range and population sizes) which may not be available for most taxa and geographic regions. We address the question of what features of the organisms or of their geographic distributions lie behind selections of potentially threatened species when there is insufficient information on temporal trends. Focusing on Iberian butterflies, we evaluate the support for past and present lists of target species from the most easily quantifiable features of the species?? ranges and conspicuousness (size and visual apparency). Among the features tested, geographic rarity has the highest weight in all the species lists. However, the explanation is rather modest statistically, especially when the species selection is of a supra-regional nature (in this case European). Among the rarest species, those with geographic ranges concentrated in the study area (a) are comparatively few and (b) on average, have less restricted ranges than those whose geographic rarity results from their marginal occurrence in the study area. Finally, the total geographic coverage of the EU-threatened butterflies is relatively large in Iberia. As a consequence species-oriented conservation planning in this region may be rather unrealistic if only geographic rarity is emphasized, or if the levels of threat determined at the supra-regional (European) level are directly translated to the regional legislations. Thus we support the regionally hierarchical approach to conservation proposed by former authors.     

Can nectar properties explain sex‐specific flower preferences in the Adonis Blue butterfly Lysandra bellargus?

1. Field observations in the Swiss Jura mountains showed that males and females of the bivoltine Adonis Blue butterfly Lysandra bellargus Rott. differed significantly in their flower visitation patterns. 2. In both generations, females visited a broader range of available nectar plants than did males. The specific flower visitation patterns of males and females were not affected by the general availability and abundance of potential nectar plant species during both flight periods, indicating high selectivity for nectar plants by both males and females. 3. In addition, the sexes differed in their nectar foraging behaviours: distances between successively visited flowers were significantly longer in males than in females, indicating that male and female butterflies have different foraging strategies. 4. Investigations of nectar characteristics showed that the sexes preferred flowers with different nectar compositions. Males of both generations preferred flowers with high proportions of sucrose and high amounts of total sugar, whereas females preferred flowers with high portions of glucose in their nectar, and, in the spring generation, flowers rich in amino acids. 5. Flowers visited exclusively by males or females in spring differed significantly in their amino acid composition. 6. This clear‐cut pattern did not hold for the autumn generation, most probably due to the limited availability of flowers. 7. The observed nectar foraging patterns underline the importance of adult feeding for longevity and reproduction in butterflies. The findings are particularly relevant for conservation, because L. bellargus is an increasingly threatened species in many European countries.     

Valeur trophique des plantes nourricières et préférence de ponte chez Parnassius apollo L. (Lepidoptera,Papilionidae)

A mountain butterfly species, Parnassius apollo is protected by the CITES convention of Washington and is threatened or extinct in many European massifs. The definition of the ecological factors which can affect its survival, in particular its relations with its larval foodplants, are important to design conservation policies. The larva of P. apollo is oligophagous and feeds on various species of Crassulaceae. The results of observations and experiments on the female laying preferences and on the efficiency of some of these plants for larval development are exposed here. The two species most cited as foodplants in literature, Sedum album and S. maximum, appeared to be the most efficient. Other species, although frequently mentioned, were rejected and another one performed poorly. A comparison with other cases of foodplant specificity in butterflies is presented and the implications of these results for conservation are discussed.     

European hare (Lepus europaeus) invasion ecology: implication for the conservation of the endemic Irish hare (Lepus timidus hibernicus)

European hare Lepus europaeus populations have undergone recent declines but the species has successfully naturalised in many countries outside its native range. It was introduced to Ireland during the mid-late nineteenth century for field sport and is now well established in Northern Ireland. The native Irish hare Lepus timidus hibernicus is an endemic subspecies of mountain hare L. timidus and has attracted major conservation concern following a long-term population decline during the twentieth century and is one of the highest priority species for conservation action in Ireland. Little is known about the European hare in Ireland or whether it poses a significant threat to the native mountain hare subspecies by compromising its ecological security or genetic integrity. We review the invasion ecology of the European hare and examine evidence for interspecific competition with the mountain hare for habitat space and food resources, interspecific hybridisation, disease and parasite transmission and possible impacts of climate change. We also examine the impact that introduced hares can have on native non-lagomorph species. We conclude that the European hare is an emerging and significant threat to the conservation status of the native Irish hare. Invasive mammal species have been successfully eradicated from Ireland before and immediate action is often the only opportunity for cost-effective eradication. An urgent call is issued for further research whilst the need for a European hare invasive Species Action Plan (iSAP) and Eradication strategy are discussed.     

Genomic diversity and differentiation of a managed island wild boar population

The evolution of island populations in natural systems is driven by local adaptation and genetic drift. However, evolutionary pathways may be altered by humans in several ways. The wild boar (WB) (Sus scrofa) is an iconic game species occurring in several islands, where it has been strongly managed since prehistoric times. We examined genomic diversity at 49 803 single-nucleotide polymorphisms in 99 Sardinian WBs and compared them with 196 wild specimens from mainland Europe and 105 domestic pigs (DP; 11 breeds). High levels of genetic variation were observed in Sardinia (80.9% of the total number of polymorphisms), which can be only in part associated to recent genetic introgression. Both Principal Component Analysis and Bayesian clustering approach revealed that the Sardinian WB population is highly differentiated from the other European populations (F_ST=0.126–0.138), and from DP (F_ST=0.169). Such evidences were mostly unaffected by an uneven sample size, although clustering results in reference populations changed when the number of individuals was standardized. Runs of homozygosity (ROHs) pattern and distribution in Sardinian WB are consistent with a past expansion following a bottleneck (small ROHs) and recent population substructuring (highly homozygous individuals). The observed effect of a non-random selection of Sardinian individuals on diversity, F_ST and ROH estimates, stressed the importance of sampling design in the study of structured or introgressed populations. Our results support the heterogeneity and distinctiveness of the Sardinian population and prompt further investigations on its origins and conservation status.     

Using a phenological network to assess weather influences on first appearance of butterflies in the Netherlands

Phenological responses of butterflies to temperature have been demonstrated in several European countries by using data from standardized butterfly monitoring schemes. Recently, phenological networks have enabled volunteers to record phenological observations at project websites. In this study, the quality of the first appearance data of butterflies from the Dutch phenological network ‘De Natuurkalender’ was examined and these data were then used to analyze trends in butterfly appearance between 2001 and 2013, the effects of climatic factors on appearance of butterflies as well as the phenological interaction of one butterfly species, Anthocharis cardamines, and its two major host plants. Although phenological networks are relatively unstructured, this study shows that data from De Natuurkalender were highly comparable to more standardized data collected by the Dutch Butterfly Monitoring Scheme. No trend in first appearance of any butterfly species was found during the time period 2001–2013. The first appearance dates of most butterflies showed, however, a clear relationship with spring temperature. Higher temperatures, especially in March and April, advanced the first appearance of butterflies. Therefore, with climatic warming in the future, earlier appearance of butterflies is expected. Although climate warming is a potential threat for phenological mismatches between different trophic levels, this study shows a similar temperature response of A. cardamines and its main host plants in the Netherlands. However, as only few phenological interactions between species are examined, further research including rarer monophagous butterfly species and their host plants is needed.     

Declines of prairie butterflies in the midwestern USA

Tallgrass prairie butterfly surveys in recent decades in four states in the USA indicate numerous declines of prairie-specialist butterflies including Speyeria idalia, Oarisma poweshiek, Atrytone arogos, Hesperia dacotae, and H. ottoe in fire-managed preserves, including large high-quality ones. These results replicate previous findings, indicating that upon initiation of conservation action, both cessation of prior management and inception of new management affect specialists negatively and that butterfly declines can be as great on reserves as non-reserves. Results at Wisconsin sites with species-specific management protocols, including permanent non-fire refugia, were more favorable for the specialists (S. idalia, Lycaeides melissa samuelis) the protocols were specifically designed to benefit. Butterfly declines after preservation will likely continue unless the conservation approach changes to include consideration of individual species’ required resources and management tolerances. The ecosystem approach assumes that habitat specialists are co-evolved with processes such as fires assumed to maintain those ecosystems. Data presented here indicate that tallgrass prairie specialist butterflies are not co-evolved with current fire regimes. An alternate perspective views ecological processes as resetting vegetation to current climate and landscape conditions. Over geologic time, relict vegetation associations persist as outliers until an event resets them. In modern times, human disturbances (especially soil-exposing ones) can reset sites to favour the more generalist species (plants and butterflies) found in the prevailing, human-degraded landscape.     

Host associations of <Emphasis Type="Italic">Coenonympha hero</Emphasis> (Lepidoptera: Nymphalidae) in northern Europe: microhabitat rather than plant species

Understanding ecological requirements of endangered species is a primary precondition of successful conservation practice. Regrettably, we know surprisingly little about the life history of numerous threatened insects, and about their use of larval host plants in particular. The brown butterflies (Nymphalidae: Satyrinae) have traditionally been considered polyphagous on grasses and indiscriminatory in their oviposition behavior. However, detailed studies on several species have revealed local specialization in host plant use as well as the decisive role of microlimatic conditions as determinants of habitat quality. The present study addresses host plant relationships in the endangered brown butterfly Coenonympha hero (L.) at the northern limit of its European distribution. We combine laboratory-based host preference and performance tests with an analysis of microhabitat use by adult butterflies in the field. Both lines of evidence suggest that C. hero is polyphagous enough not to be associated with one particular host species. Oviposition choices of C. hero are not driven by host plant species but rather by structural characteristics of the substrate. The preferred rigid needle-like structures may serve as cues of ‘transparent’ vegetation which allows the larvae to benefit from sunlight reaching the lower strata of the tuft. Our results suggest that conservation efforts should prioritize microclimatic parameters, rather than the presence of any particular host plant species, as decisive determinants of habitat quality in C. hero.     

Host plant preference in the protected myrmecophilous Transylvanian Blue (<Emphasis Type="Italic">Pseudophilotes bavius hungarica</Emphasis>) butterfly (Lepidoptera: Lycaenidae) and its relationship with potential ant partners

When selecting specific host plants, caterpillars of many lycaenid butterflies, such as the protected Pseudophilotes bavius hungarica, are known to engage in various interactions with ants, which help them survive. Although P. bavius is a protected species, data about its host plant selection is very scarce, and little information is available on its myrmecophilous relationships. Our aim was to identify the host plant characteristics that determine the occurrence of the caterpillar and to clarify the specificity of its myrmecophily. We conducted a series of field surveys regarding host plant characteristics. Laboratory experiments were carried out to investigate the nature of interactions between the caterpillar and its potential ant partners. Control experiments involving non-visiting ants were also performed. On the basis of our findings, the physical characteristics of host plants do not seem to influence host plant choice, but the absence of aphids and the presence of different ant species proved important. According to the results of behavioural assays, neutral reactions to the caterpillars were recorded in the case of ant species that regularly visited the host plant (Lasius paralienus, Camponotus aethiops), in contrast to Tapinoma subboreale, which was not observed at all on the host plants and which behaved aggressively towards the larvae. Therefore, the caterpillar is expected to show a certain ant host selectivity. The study constitutes an essential contribution to our knowledge of the natural history of a protected butterfly species, which can be used as a basis for more appropriate management strategies, while also shedding light on aspects of myrmecophilous relationships in Lycaenidae in general.     

A resource-based conservation approach for an endangered ecotone species: the Ilex Hairstreak (Satyrium ilicis) in Flanders (north Belgium)

Ecotones are often species-rich and harbour specific resources and environmental conditions for invertebrates. Despite their functional significance for conservation, they are often not explicitly included in biotope typologies relevant to conservation policy and management (e.g., the European Habitats Directive). The Ilex Hairstreak (Satyrium ilicis) is a species of European conservation concern and a typical ecotone species inhabiting gradients from open (e.g., heathland, grassland) to closed vegetation (e.g., woodland). Here, we investigated its occurrence and habitat use at different spatial scales in Flanders (north Belgium). At a regional scale, species distribution modelling predicted 1,152 grid cells of 1 × 1 km² to be suitable of which 190 were presumed to occur within colonization capacity (±2.5 km). At a local scale, adult butterflies were more abundant on sites sheltered by bushes and small trees and with nectar sources in the vicinity of tall oak trees (mate locating sites). For egg-laying, females preferred oaks of intermediate height (50–150 cm) with many low branches at some distance from the nearest woodland edge (12 m). Additionally, Alder Buckthorn (Frangula alnus) was abundant as well as a herb layer of 10–15 cm. 73 % of the eggs were parasitized and parasitism occurred more often within sites where small oaks were very abundant. Making use of our results, we suggest conservation measures at different scales for this endangered ecotone species: policy measures at a regional level to delineate functional conservation units and local management measures using a resource-based approach.     

Central European vascular plants requiring priority conservation measures – an analysis from national Red Lists and distribution maps

A joint analysis considering the world-wide distribution and threat status of Central European vascular plants was carried out to derive conservation priorities for threatened species. A list of 417 taxa is presented, which are threatened throughout Central Europe and/or show a predominantly Central European distribution. As a first step, all plants mentioned in Central European national Red Lists were included in a synoptic table, resulting in a total of 3255 taxa threatened or rare in at least one country. To select species with a high conservation priority, two parameters were estimated: threat status for Central Europe and a new category termed responsibility for the conservation of a species. As criteria for this second parameter, we used the proportion of Central Europe on the world range of a species, the position of Central Europe within this range, and its world-wide threat status. A simple category system including four responsibility categories is proposed. For all species selected, threat status and a responsibility assessment for the whole of Central Europe is given, as well as position and proportion of Central Europe on their world range. By comparison of threat status and responsibility, this list provides a background for assessing national conservation priorities as well as for making decisions about inclusion in international conventions on species conservation. This was shown by a comparison of the species selected using this approach with those included in the two most important European instruments for species conservation – the Berne Convention and the Habitats Directive.     

Resource use of specialist butterflies in agricultural landscapes: conservation lessons from the butterfly Phengaris (Maculinea) nausithous

Most of the European grassland butterfly species are dependent on species rich grasslands shaped by low intensity farming. Conservation of these specialist species in agricultural landscapes relies on knowledge of their essential resources and the spatial distribution of these resources. In The Netherlands, the dusky large blue Phengaris (Maculinea) nausithous butterflies were extinct until their reintroduction in 1990. In addition, a spontaneous recolonization of road verges in an agricultural landscape occurred in 2001 in the southern part of The Netherlands. We analyzed the use of the essential resources, both host plants and host ants, of the latter population during the summers of 2003 and 2005. First we tested whether the distribution of the butterflies during several years could be explained by both the presence of host plants as well as host ants, as we expected that the resource that limits the distribution of this species can differ between locations and over time. We found that oviposition site selection was related to the most abundant resource. While in 2003, site selection was best explained by the presence of the host ant Myrmica scabrinodis, in 2005 it was more strongly related to flowerhead availability of the host plant. We secondly compared the net displacement of individuals between the road verge population and the reintroduced population in the Moerputten meadows, since we expected that movement of individuals depends on the structure of their habitat. On the road verges, butterflies moved significantly shorter distances than on meadows, which limits the butterflies in finding their essential resources. Finally we analyzed the availability of the two essential resources in the surroundings of the road verge population. Given the short net displacement distances and the adverse landscape features for long-distance dispersal, this landscape analysis suggests that the Phengaris population at the Posterholt site is trapped on the recently recolonized road verges. These results highlight the importance of assessing the availability of essential resources across different years and locations relative to the movement of the butterflies, and the necessity to careful manage these resources for the conservation of specialist species in agricultural landscapes, such as this butterfly species.     

Extinction threat evaluation of endemic fig trees of New Caledonia: Priority assessment for taxonomy and conservation with herbarium collections

This article focuses on the relationship between priority-setting in conservation and in taxonomy. A simple and generally applicable scheme is presented based on prior quantitative extinction threat evaluation. In the main part of the study we describe the assessment of the herbarium voucher collection date time series of 21 endemic fig tree species of Ficus sect. Oreosycea (Moraceae). The fig tree assessment is then compared with the available IUCN Red List data and with the collection information on two other groups of endemic tree radiations in New Caledonia: ebonies of Diospyros sect. Maba (Ebenaceae) and the Iguanura palm lineage (Arecaceae). We find a remarkably low level of extinction threat evident in Ficus but a pronounced need to differentiate between true species rarity and putative rarity of potential taxonomic artifacts. To this end it is proposed how such numerical evaluations can be used to set future priorities for the assessment or validation of the taxonomic and conservation status of taxa. The limitations and implications of the evaluation are discussed and relevant criteria for a meaningful analysis of collection records are listed. Finally, putting our results on woody plants into perspective, we briefly review the general conservation situation and outlook of New Caledonia, acknowledging both its high conservation priority and potential. Abbreviations: Note that different IUCN threat category classifications have been in use during the last decade and that some of the cited categories and their abbreviations have changed (IUCN 1994, 2001).     

How life history affects threat status: Requirements of two Onobrychis-feeding lycaenid butterflies, Polyommatus damon and Polyommatus thersites, in the Czech Republic

Comparisons of related species differing in conservation status may offer insights into causes of species declines. We studied egg-laying patterns and landscape occupancy of two sympatric lycaenidae butterflies inhabiting xeric grasslands, vulnerable Polyommatus thersites and critically endangered Polyommatus [Agrodiaetus] damon, both developing on sainfoin, Onobrychis spp. Females of bivoltine P. thersites oviposit on host plant leaves at a relatively low height (??20 cm), in both spring (May?CJune) and summer (July?CAugust) generations. Females of univoltine P. damon (July?CSeptember) oviposit to senescing inflorescences, in significantly higher heights (>30 cm), and the species is hence vulnerable to summer mowing or grazing. On a landscape scale, both species tended to occur at sites with diverse sward management, including temporarily unmanaged patches. In addition, P. damon occurred only in the proximity of other occupied sites. The study documents that grassland management must respect the needs of the most vulnerable species, and because these needs are seldom known, it must maintain a high diversity of conditions within individual sites.     

Integrating three comprehensive data sets shows that mitochondrial DNA variation is linked to species traits and paleogeographic events in European butterflies

Understanding the dynamics of biodiversity, including the spatial distribution of genetic diversity, is critical for predicting responses to environmental changes, as well as for effective conservation measures. This task requires tracking changes in biodiversity at large spatial scales and correlating with species functional traits. We provide three comprehensive resources to understand the determinants for mitochondrial DNA differentiation represented by (a) 15,609 COI sequences and (b) 14 traits belonging to 307 butterfly species occurring in Western‐Central Europe and (c) the first multi‐locus phylogenetic tree of all European butterfly species. By applying phylogenetic regressions we show that mitochondrial DNA spatial differentiation (as measured with G_ST, G′_ST, D and D_ST) is negatively correlated with species traits determining dispersal capability and colonization ability. Thanks to the high spatial resolution of the COI data, we also provide the first zoogeographic regionalization maps based on intraspecific genetic variation. The overall pattern obtained by averaging the spatial differentiation of all Western‐Central European butterflies shows that the paradigm of long‐term glacial isolation followed by rapid pulses of post‐glacial expansion has been a pervasive phenomenon in European butterflies. The results and the extensive data sets we provide here constitute the basis for genetically‐informed conservation plans for a charismatic group in a continent where flying insects are under alarming decline.