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Cultural landscapes, shaped by centuries of traditional low-intensity agricultural practices, have been declining all over the world. In Transylvania (Romania), traditionally mown and extensively grazed grasslands have been part of a diverse landscape mosaic for centuries. In contrast to Western European countries, these species-rich grasslands are still present in Transylvania, but have declined in recent years, due to the pressure of intensification or abandonment, and inconsistent land use policies. The quality of these grasslands could easily be assessed using plants and butterflies, which are considered among the best indicators for habitat quality because of their characteristic response to land use change. Our study aimed to assess butterfly and plant community assemblages, richness and diversity in Transylvania’s most typical grassland type, by using transect and releve methods. We investigated the drivers of change in butterfly and plant community assemblages, and decline in biodiversity of basiphilous dry grasslands. We found that present and past land use practices, geographic distance between sites and soil physical–chemical characteristics have major impacts on different aspects of plant and butterfly diversity (like species composition and richness). Grasslands that were converted to croplands in the past have lost their typical species assemblages and have not completely recovered in the last 30 years. Mown grasslands supported the most diverse communities of butterflies and plants, and diversity declined with land use change to extensive and then intensively grazed pastures. For the conservation of basiphilous dry grasslands in Transylvania, we recommend a case-by-case analysis of grasslands, with emphasis on prioritizing long-term traditional mowing when applying agro-environmental schemes.

Social systems are attractive targets for parasites. Once infiltrated they could manipulate the host to contribute to their further dispersal. A wide array of parasites causes summit disease driving their host up on a grass blade from where propagules are then dispersed. In ants, previous observations suggested the existence of a social prophylactic strategy that could help reduce the pathogen’s dispersal success through early corpse disposal in the case of summit causing pathogenic Pandora fungus. We experimentally tested the efficiency of such prophylactic mechanisms in a large nest complex using fresh ant corpses and dummies fixed to grass blades. Indeed, ants discovered and disposed of corpses very efficiently, primarily of those close to the nest margin, while dummies were mostly neglected. We argue that this behavior is not necessarily specific, but rather part of a general set of behaviors that could be of use to fight other pathogens as well that cause summit disease.

The article presents the AMS (accelerator mass spectrometry) radiocarbon dating results of the Giant of Bevoay, which is a very large Grandidier baobab (Adansonia grandidieri Baill.) of Madagascar. The investigation of this baobab shows that it has a cluster structure, which consists of 3 perfectly fused stems. The calculated wood volume of the tree is 520 m3, which makes it the third largest Grandidier baobab and also the third largest individual of all Adansonia species. Two samples were collected from the outer part of the stems. The oldest dated sample segment had a radiocarbon date of 525 ± 23 BP, which corresponds to a calibrated age of 585 ± 10 years. According to this value, the Giant of Bevoay is 825 ± 50 years old.

Records from Austria, Hungary, Ukraine and the Republic of Moldova collected in the last 30 years suggest that Xestia sextrigata (Haworth, 1809) is extending its range towards South-Eastern Europe. Here we report the first genuine record of X. sextrigata from Romania. Older records from the literature are shown to be erroneous.

The volcanic Comoro Islands, located in the Indian Ocean in between mainland Africa and Madagascar, host several thousand African baobabs (Adansonia digitata). Most of them are found in Mayotte, which currently belongs to France, as an overseas department. Baobabs constitute a reliable archive for climate change and millennial specimens were recently used as proxies for paleoclimate reconstructions in southern Africa. We report the investigation of the largest two baobabs of Mayotte, the Big baobab of Musical Plage and the largest baobab of Plage N’Gouja. The Big baobab of Musical Plage exhibits a cluster structure and consists of 5 fused stems, out of which 4 are common stems and one is a false stem. The baobab of Plage N’Gouja has an open ring-shaped structure and consists of 7 partially fused stems, out of which 3 stems are large and old, while 4 are young. Several wood samples were collected from both baobabs and analyzed via radiocarbon dating. The oldest dated sample from the baobab of Musical Plage has a radiocarbon date of 275 ± 25 BP, which corresponds to a calibrated calendar age of 365 ± 15 yr. On its turn, the oldest sample from Plage N’Gouja has a radiocarbon date of 231 ± 20 BP, corresponding to a calibrated age of 265 ± 15 yr. These results indicate that the Big baobab of Musical Plage is around 420 years old, while the baobab of Plage N’Gouja has an age close to 330 years. In present, both baobabs are in a general state of deterioration with many broken or damaged branches, and the Baobab of Plage N’Gouja has several missing stems. These observations suggest that the two baobabs are in decline and, most likely, close to the end of their life cycle.

Over the past years, our research on baobabs mainly focused on the largest Malagasy species, namely the Reniala or Grandidier baobab (Adansonia grandidieri Baill.). The biggest A. grandidieri are located in the Morombe area, especially in the so-called Andombiry Forest. This giant forest of Reniala hosts well over 6000 mature individuals, out of which more than 30 have very large sizes, i.e., circumferences over 20 m. We investigated, measured and dated by AMS radiocarbon the largest specimens. We found that all large Grandidier baobabs are multi-stemmed. They mostly exhibit a closed ring-shaped structure, with a false cavity inside. In this architecture, which enables Grandidier baobabs to reach very large sizes, the stems that build the ring typically have similar ages. Here we present the AMS radiocarbon investigation of two large baobabs, A 215 (girth 21.50 m) and A 257 (girth 25.70 m). According to dating results, the baobab A 215 has an age of only 375 years. It consists of four fused stems and has a closed ring-shaped structure. The baobab A 257 has the second largest trunk of all known live Reniala trees. It also exhibits a closed ring-shaped structure, with five fused stems around a false cavity, which has an opening toward the exterior. The dating results indicate that A 257 is around 900 years old.

The article discloses the accelerator mass spectrometry (AMS) radiocarbon dating results of the Big Reniala of Isosa, which is a massive Grandidier baobab (Adansonia grandidieri Baill.) of Madagascar. The investigation of this baobab shows that it consists of 5 perfectly fused stems and exhibits a cluster structure. The calculated wood volume of the tree is 540 m 3 , which makes the Big Reniala of Isosa the largest individual of all Adansonia species and also the biggest known angiosperm in terms of volume. Several samples were collected from the outer part of the stems. The oldest dated sample had a radiocarbon date of 934 ± 24 BP, which corresponds to a calibrated age of 845 ± 25 years. This value indicates an age of 1000 ± 100 years for the big Reniala of Isosa.

The widespread use of pesticides, changes in the structure of the landscape due to industrial and agricultural uses, and climate change have massively affected insect populations. The decline in insect biodiversity and biomass is documented in some countries in Europe, Asia, and North America. Romania, compared to Western and Central European countries, is considered to preserve a less altered nature and high biodiversity, being often given as a positive example in terms of conservation of natural and seminatural structures of the landscape. Unfortunately, the reality is different. The negative trends highlighted in Central European countries are reflected almost at the same intensity in Romania. During the communist era (1965–89), Romania reached the maximum percentage of land use for agricultural purposes. To increase production, intensive land use was associated with the application of impressive amounts of pesticides, the scale of which is unfortunately not officially known. Due to the collapse of the economy during the postcommunist period (1990–2000), nature had a short break which allowed it to recover. After 2000, agriculture has returned to an upward trend dominated increasingly by large landowners who in recent years have altered and destroyed the majority of the mosaic-type cultural landscape in Transylvania. At the same time, the vast deciduous and softwood forests of the Carpathians were strongly fragmented and reduced in area. Due to the global warming, the species of butterflies that emerge in spring show an obvious shift of flight periods toward March. On the other hand, species with a flight period until the beginning of autumn extend their flight period until the end of October or the beginning of November. In the period 1930–2019, the gap of the flight period toward the beginning of spring or before the end of autumn sums for some species 30 days. All this has led to a decline in butterfly populations. This paper presents for the first time the documented decline of butterflies in a Southeastern European country. Using the data regarding butterflies from the surroundings of Cluj from the period 1920–2019, we could show that 16 butterfly species have disappeared and 29 species have gone through a massive population decline. On the other hand, in the Red List of Romanian Lepidoptera, 25.11% species are considered endangered.

Author Posting. © Studia Chemia, 2018. Studia Universitatis Babes-Bolyai Chemia is an Open Access Journal (read, download, copy, distribute, print for research use, search, or link to the full texts of articles). The definitive version was published in Studia Universitatis Babes-Bolyai Chemia 63(4), (2018): 7-13, doi: 10.24193/subbchem.2018.4.01.

Author Posting. © Studia Chemia, 2018. Studia Universitatis Babes-Bolyai Seria Chemia is an Open Access Journal (read, download, copy, distribute, print for research use, search, or link to the full texts of articles). The definitive version was published in Studia Universitatis Babes-Bolyai, Seria Chemia 63, no. 3 (2018): 41-48, doi:10.24193/subbchem.2018.3.03.

The article discloses the AMS (accelerator mass spectrometry) radiocarbon dating results of the historic Big Tree at Victoria Falls, Zimbabwe. The research aimed to determine the age, growth and architecture of this renowned African baobab. The superlative baobab is composed of five main stems, three young stems and one false stem. It exhibits an open ring-shaped structure, an architecture that allows baobabs to reach large sizes and old ages. Several wood samples extracted from four stems were dated by radiocarbon. The oldest sample had a radiocarbon date of 978 ± 14 BP, corresponding to a calibrated age of 955 ± 20 calendar years. By this value, the Big Tree at Victoria Falls is 1150 ± 50 years old. We found that the eight common stems belong to three generations, which are 1000–1100, 600–700 and 200–250 years old, respectively. The false stem is 550 years old. The stems belonging to the oldest generation stopped growing over 100 years ago.

Herbivores and their predators are affected by changes in land-use and habitat fragmentation. Past studies of tri-trophic herbivore communities have found that increasing land-use intensity leads to declines in community stability. The majority of these studies analysed community stability in highly fragmented ecosystems characterised by intensive agriculture. In this study we considered how landscape configuration and composition affected habitat networks and parasitoid food webs under moderate but increasing land use. We used gall wasp communities as models to test the effects of landscape change on multi-species hierarchical communities of plants and animals. We investigated characteristics of networks formed by rose bushes and quantitative webs of rose gall parasitoids along a gradient of land-use intensity. We found that link density and compartmentalisation of rose bush networks, and local extinction within parasitoid webs increased with increasing landscape homogenization. Because these network and web characteristics are linked with resilience, our results suggest that stability of these communities can increase as landscapes become less complex. This is an intriguing aspect of landscape homogenisation effects on biological communities that contrasts with most expectations and the majority of the relevant literature, where decreasing community stability is usually associated with landscape homogenization.

We investigated the systematics and biogeography of the West-Palaearctic water cricket genus Velia Latreille based on a phylogenetic analysis of five molecular markers obtained from 79% of all known taxa of the subgenera Velia (s.s.) and Velia (Plesiovelia) Tamanini. The results revealed a sister-group relationship between Velia (Plesiovelia) and the monotypic subgenus Velia (s.s.), and showed that the former is divided into three major clades. All taxa of Velia (Plesiovelia) were recovered as monophyletic, except for V. (P.) serbica Tamanini, which was paraphyletic with respect to V. (P.) mancinii mancinii Tamanini. Our results also indicate the existence of several unrecognized species. Molecular dating based on fossil data and COI rates indicates that the split between Velia (s.s.) and Velia (Plesiovelia) occurred between 40 and 22 Ma. An ancestral area reconstruction suggests that the latter originated in southeastern Europe, from where it radiated to the west and east, along the Neogene archipelagos of Europe and Asia Minor. Northwestern Africa served as the second most important diversification centre of the subgenus. The low genetic variability in the widespread V. (P.) caprai caprai Tamanini and V. (P.) saulii Tamanini implies a rapid postglacial colonization of Europe, whereas high diversity within the lineages of V. (P.) serbica indicates survival of Pleistocene glaciations in microrefugia throughout southeastern Europe. These results serve as a useful framework for future studies ranging from the systematics of the group to historical biogeography, ecology and biodiversity conservation.

Author Posting. © Studia Chemia, 2017. This article is posted here by permission of Studia Chemia for personal use, not for redistribution. The definitive version was published in Studia Universitatis Babes-Bolyai, Seria Chemia 62, no. 2, Tom 2 (2017): 347-354, doi:10.24193/subbchem.2017.2.27.

The article presents the radiocarbon investigation of the baobab of Jhunsi, Allahabad and the Parijaat tree at Kintoor, two old African baobabs from northern India. Several wood samples extracted from these baobabs were analysed by using AMS radiocarbon dating. The radiocarbon date of the oldest samples were 779 ± 41 BP for the baobab of Jhunsi and 793 ± 37 BP for the baobab of Kintoor. The corresponding calibrated ages are 770 ± 25 and 775 ± 25 calendar years. These values indicate that both trees are around 800 years old and become the oldest dated African baobabs outside Africa.

The year 2016 witnessed the fall of a symbol of the botanical world: the historic Chapman baobab of Botswana. This article presents the results of our investigation of the standing and fallen tree. The Chapman baobab had an open ring-shaped structure composed of six partially fused stems. Several wood samples collected from the stems prior and after their collapse were analysed by using radiocarbon dating. The radiocarbon date of the oldest sample was 1381 &plusmn, 22 BP, which corresponds to a calibrated age of 1345 (+10, &minus, 15) calendar years. The dating results show that the six stems of the Chapman baobab belonged to three different generations, which were 1350&ndash, 1400, 800&ndash, 1000 and 500&ndash, 600 years old. The growth rate variation of the largest and oldest stem is presented and correlated with the climate evolution in the area over the past 1000 years. The factors that determined the sudden fall and death of the Chapman baobab are also presented and discussed.

The article reports the growth stop phenomenon, which was documented only for baobabs, i.e. for trees belonging to the Adansonia genus. The identification of growth stop was enabled by radiocarbon dating, which allows a complex investigation of samples collected from the trunk/stems of baobabs. In several cases, the outermost rings of baobabs, which were close to the bark, were found to be old, with ages of several hundreds of years, instead of being very young. Dating results of samples collected from six baobabs are presented. For multistemmed baobabs, the growth stop may occur only for one or several stems. We identified four factors that may induce the growth stop: (i) stress determined by severe climate conditions, (ii) old age, (iii) the need to keep a stable internal architecture, and (iv) the collapse of stems that survive this trauma. Baobabs and their stems affected by growth stop may survive for several centuries, by continuing to produce leaves, flowers, and fruits. This phenomenon was associated with the capacity of baobabs to store large amounts of water in their trunks/stems in the rainy season. This reservoir of water is used during the dry season and allows the trees to survive prolonged drought periods.

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.

An annotated review of the Mesoveliidae (Hemiptera: Heteroptera: Gerromorpha) of the south-east European countries is provided. Mesovelia thermalis Horvath, 1915 is recorded for the first time from Romania outside of its type locality and for the first time from Bulgaria, Serbia, and Croatia. Therefore, its European geographical range is two times larger than previously known. Mesovelia vittigera Horvath, 1895 is excluded from the faunas of Romania and Moldova based on proven or suspected misidentifications and new information is provided about the distribution of M. furcata Mulsant et Rey, 1852. We analysed the phylogenetic relationships of M. thermalis within the genus and further examined additional south-east European individuals of M. vittigera and M. furcata. The results revealed that M. thermalis is a possible sister species to M. furcata, and that the south-eastern individuals of both M. vittigera and M. furcata are closely related to their conspecifics. Molecular dating based on fossil ...

Background Habitat quality is one main trigger for the persistence of butterflies. The effects of the influencing biotic and abiotic factors may be enhanced by the challenging conditions in high-alpine environments. To better our knowledge in this field, we performed a mark-release-recapture study with Boloria pales in the Southern Carpathians. Methods We analysed population structure, movement and foraging behaviour to investigate special adaptations to the alpine environment and to reveal differences between sexes. We compared these aspects in one sector with and one sector without grazing to address the effects of grazing intensity on habitat quality. Results We observed “soft” protandry, in which only a small number of males appeared before females, and an extended emergence of individuals over the observed flight period, dividing the population’s age structure into three phases; both observations are considered adaptations to high mountain environments. Although both sexes were mostly sedentary, movement differences between them were obvious. Males flew larger distances than females and were more flight-active. This might explain the dimorphism in foraging behaviour: males preferred nectar sources of Asteraceae, females Caprifoliaceae. Transition from the grazed to the ungrazed sector was only observed for males and not for females, but the population density was higher and the flight distances of the individuals were significantly longer on the grazed sector compared with the ungrazed one. Conclusion Soft protandry, an extended emergence of the individuals and an adapted behavioural dimorphism between sexes render to represent a good adaptation of B. pales to the harsh environmental conditions of high mountain ecosystems. However, land-use intensity apparently has severe influence on population densities and movement behaviour. To protect B. pales and other high-alpine species from the negative consequences of overgrazing, areas without or just light grazing are needed. Electronic supplementary material The online version of this article (10.1186/s12983-018-0298-1) contains supplementary material, which is available to authorized users.

In agro-ecosystems, environmental monitoring is fundamental to detect and survey changes related to land use change and management practices. Butterflies and moths have often been suggested as suitable indicators for monitoring environmental effects on biodiversity in farmlands. Here, we estimated the required sample size and monitoring effort necessary to run a Lepidoptera survey in European farmland, assessing in particular if monitoring investment would differ between representative bio-geographical regions.We operated linear 1-km long transect routes in farmland of Romania, Spain and Sweden from 2013 to 2015, and recorded butterflies and burnet moths (Papilionoidea, Zygaenidae). The transects were walked back and forth four times a season, and replicated yearly. The lepidopteran diversity was high in farmlands of Romania and Spain, but comparatively low in Sweden. The coefficient of variation (CV) of recorded species number differed between countries being lowest in Sweden and highest in Spain. In general, the CV dropped above a transect length of 400–800 m, thus indicating an increase in statistical power. Assuming a non-parametric test for matched samples, power calculations were conducted with the raw count data and with log-transformed count data for comparison. When using log-transformed data, the required sample size to detect an effect was less than 10 transects per country or region (in order to detect a 10% loss of species or a decrease of 30% in total abundance). Specific subgroups of species, e.g. protected species or specific indicator groups, showed a higher variance, thus requiring a higher sample size to detect effects ranging from 12 to 16 transects (equivalent to 21–29 working days per country and year). When using original, untransformed count data a considerably larger sample size would be needed. Actual time to be invested in field work differed between countries due to contrasting regional constraints and conditions. Nevertheless, the final monitoring effort in working days was similar between countries as the factors involved balanced out each other, in particular due to the differing year-to-year variations.Our study demonstrated the feasibility of an environmental monitoring programme in arable land using farmland butterflies across Europe. We present a suitable approach and guidelines as well as the necessary effort to be invested in future Europe-wide monitoring programmes of butterflies in agro-ecosystems, based on predictions of statistical power. In agro-ecosystems, environmental monitoring is fundamental to detect and survey changes related to land use change and management practices. Butterflies and moths have often been suggested as suitable indicators for monitoring environmental effects on biodiversity in farmlands. Here, we estimated the required sample size and monitoring effort necessary to run a Lepidoptera survey in European farmland, assessing in particular if monitoring investment would differ between representative bio-geographical regions.We operated linear 1-km long transect routes in farmland of Romania, Spain and Sweden from 2013 to 2015, and recorded butterflies and burnet moths (Papilionoidea, Zygaenidae). The transects were walked back and forth four times a season, and replicated yearly. The lepidopteran diversity was high in farmlands of Romania and Spain, but comparatively low in Sweden. The coefficient of variation (CV) of recorded species number differed between countries being lowest in Sweden and highest in Spain. In general, the CV dropped above a transect length of 400–800 m, thus indicating an increase in statistical power. Assuming a non-parametric test for matched samples, power calculations were conducted with the raw count data and with log-transformed count data for comparison. When using log-transformed data, the required sample size to detect an effect was less than 10 transects per country or region (in order to detect a 10% loss of species or a decrease of 30% in total abundance). Specific subgroups of species, e.g. protected species or specific indicator groups, showed a higher variance, thus requiring a higher sample size to detect effects ranging from 12 to 16 transects (equivalent to 21–29 working days per country and year). When using original, untransformed count data a considerably larger sample size would be needed. Actual time to be invested in field work differed between countries due to contrasting regional constraints and conditions. Nevertheless, the final monitoring effort in working days was similar between countries as the factors involved balanced out each other, in particular due to the differing year-to-year variations.Our study demonstrated the feasibility of an environmental monitoring programme in arable land using farmland butterflies across Europe. We present a suitable approach and guidelines as well as the necessary effort to be invested in future Europe-wide monitoring programmes of butterflies in agro-ecosystems, based on predictions of statistical power.

Shores of channels with thermal water provide an adequate microclimate for maintaining wolf spiders in activity during winter. Of the spiders collected after the winter survey of 22 thermal habitats from western Romania, 93.02% were juveniles and subadults, while the remaining individuals belonged to the following seven species: Arctosa leopardus, Pardosa amentata, Pardosa proxima, Pirata piraticus, Piratula latitans, Trochosa robusta and Trochosa ruricola. The reproductive period of some species is altered under the influence of neighbouring hot waters, as revealed by the capture of females with egg sacs and spiderlings, during winter.

Quaternary climatic oscillations caused severe range expansions and retractions of European biota. During the cold phases, most species shifted to lower latitudes and altitudes, and expanded their distribution range northwards and to higher elevations during the warmer interglacial phases. These range shifts produced contrasting distribution dynamics, forming geographically restricted distribution patterns but also panmictic distributions, strongly dependent on the ecologic demands of the species. The two closely related butterfly species Erebia ottomana Herrich-Schaffer, 1847 and Erebia cassioides (Reiner & Hohenwarth, 1792) show subalpine and alpine distribution settings, respectively. Erebia ottomana is found up to the treeline (1400–2400 m a.s.l.), whereas E. cassioides reaches much higher elevations (from about 1800 m a.s.l. in the Retezat Mountains, in Romania, to 2800 m a.s.l.). Thus, both species cover diverging climatic niches, and thus might also have been distributed differently during the cold glacial stages. Individuals of these two species were sampled over the mountain areas of the Balkan Peninsula and genetically analysed using allozyme electrophoresis. Additionally, we performed species distribution models (SDMs) to simulate the distribution patterns of both species in the past (i.e. during the Last Glacial Maximum and the Atlanticum). Our genetic data show contrasting structures, with comparatively low genetic differentiation but high genetic diversity found in E. ottomana, and with stronger genetic differentiation and a lower level of genetic diversity, including many endemic alleles, occurring restricted to single mountain massifs in E. cassioides. The SDMs support a downhill shift during glacial periods, especially for E. ottomana, with possible interconnection among mountain regions. We conclude that during the cold glacial phases, both species are assumed to shift downhill, but persisted at different elevations, with E. ottomana reaching the foothills and spreading over major parts of the Balkan Peninsula. In contrast, E. cassioides (the truly alpine species) survived in the foothills, but did not reach and spread over lowland areas. This more widespread distribution at the Balkan Peninsula of E. ottomana compared with E. cassioides is strongly supported by our distribution models. As a consequence, long-term geographic restriction to distinct mountain massifs in E. cassioides versus panmixia in E. ottomana produced two contrasting evolutionary scenarios. © 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 112, 569–583.

The Alcon Blue Maculinea alcon and the Mountain Alcon Blue Maculinea 'rebeli' are obligate ant-parasitic butterflies with no distinct morpho- logical and genetic differences but clear ecological separation. 2. The two butterflies generally lay their eggs on distinct host plant species: M. alcon on Gentiana pneumonanthe and M. 'rebeli 'o nGentiana cruciata. The egg-laying behaviour of these two ecotypes has previously only been investi- gated in sympatric, but not in syntopic populations. We studied the egg-laying preferences of M. alcon and M. 'rebeli' in a unique area where they co-occur, and where they use different host plants. 3. The distance to the nearest other host plant does not seem to influence the decision of female butterflies as to whether to lay eggs on a specific host plant. 4. The two butterflies laid their eggs on different parts of their host plants: M. alcon preferred the sepals of G. pneumonanthe flower buds, while M. 'rebeli' laid most eggs on the leaves of G. cruciata. 5. The major factor correlated with the number of eggs laid on the host plant seemed to be plant quality (number of flowers, stem length, etc.) for both butterflies. 6. The present study reveals behavioural differences between the two Alcon Blue forms under unique syntopic conditions, a hidden intraspecific diversity that is worth conserving.

Demographic parameters such as survival, sex ratio and abundance can profoundly affect the viability of populations and thus are of primary importance in species of conservation concern. Although numerous studies have been published on certain aspects of the ecology and evolution of the endangered Large Blue butterfly Maculinea arion, there is still a lack of detailed knowledge on its populations’ demography. Moreover, M. arion populates a variety of xerothermic habitats throughout its European range using various food plants and host ants, which leads to complications in its conservation. Our aim was to estimate demographic parameters of M. arion populations in different parts of its European range. Detailed mark-recapture sampling was conducted on populations in four different countries. We often found that daily apparent survival probability declined with increasing age of individuals, but there was no difference between male and female survival. In smaller populations, the sex ratio was rather female-biased. Our most interesting result was the lack of protandry in some populations that might be a consequence of selection against reproductive asynchrony in small populations or a polyandrous mating system. The perfect coincidence of male and female phenology can positively affect the effective population size, because the lack of reproductive asynchrony increases the chance of male–female encounters. Abundance of the studied populations ranged between 100 and 1,600 individuals, smaller populations were on the verge of extinction. Habitat of the threatened small populations was either overgrazed or abandoned, while habitat of larger, stable populations was lightly grazed.