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Understanding the circumstances under which insect herbivores will adopt a novel host plant is a longstanding question in basic and applied ecology. While geographic variation in host use can arise through differences in both herbivore preference and plant characteristics, there is a tendency to attribute geographic variation in host use to regional differences in herbivore preference alone. This is especially true for herbivores specialized to one or a few plant species. We compared how geographic variation in herbivore preference and host plant origin shape regional differences in host plant use by the specialized herbivore, Euphydryas phaeton. In parts of its range, E. phaeton uses only a native host, Chelone glabra, while in others, it also uses an introduced host, Plantago lanceolata. We offered female butterflies from each region the non-native host plant sourced from both regions and compared their oviposition behavior. The non-native host was almost universally rejected by butterflies in the region where only the native plant is used. In the region where butterflies use both hosts, females accepted non-native plants from their natal region twice as often as non-native plants from the other region where they are not used. Acceptance differed substantially among individual butterflies within regions but not among plants within regions. Thus, both individual preference and regional differences in both the insect and non-native host contributed to the geographic variation in different ways. These results highlight that, in addition to herbivore preference, regional differences in perceived plant suitability may be an important driver of diet breadth.

Since the phenomenon of mimicry was first described by Bates in 1862 it has become one of the foundational examples of adaptive evolution. Numerous subcategories of mimicry and dozens of hypotheses pertaining to its evolution and maintenance have been proposed. Many of these hypotheses, however, are difficult to test in experimental settings, and data from natural observations are often inadequate. Here we use data from a long-term survey of butterfly presence and abundance to test several hypotheses pertaining to Batesian and female-limited polymorphic mimicry (FPM; a special case of Batesian mimicry). We found strong evidence that models outnumber mimics in both mimicry systems, but no evidence for an increase in relative abundance of FPM mimics to their Batesian counterparts. Tests of the early-emergence/model first hypothesis showed strong evidence that the Batesian mimic routinely emerges after the model, while emergence timing in the FPM system was site specific, suggesting that other ecological factors are at play. These results demonstrate the importance of long-term field observations for testing evolutionary and ecological hypotheses.

The marsh fritillary Euphydryas aurinia is declining across Europe and is of high conservation interest. Its ecology has been defined and its conservation status assessed primarily from the affinities and populations of young caterpillars in the autumn, before hibernation and high winter mortality. The possibility that caterpillars of E. aurinia can overwinter more than once was investigated on the Isle of Islay, Scotland after caterpillars were found to occur at some locations in the spring despite a pre-hibernation absence. Closely-related species in North America and Northern Europe can prolong larval development by diapausing for a year as does E. aurinia in Scandinavia. Measurements of development and manipulations of distribution confirmed that some caterpillars do extend the life-cycle in Scotland and may occur in areas devoid of larvae in their first year. Caterpillars attempting this life-cycle develop slowly in spring, attain the normal penultimate spring instar and then enter diapause while other caterpillars are pupating. They moult just before diapause, construct highly cryptic webs and on emergence the following spring are 5–6 times heavier than larvae emerging in their first spring, or the equivalent of a month or so ahead. They attain a final, extra instar as larvae in their first spring reach the penultimate instar. Knowledge of this life-cycle is confined in the UK to Islay but its occurrence in this mild climate implies that it is more widespread. Implications for insect conservation Conditions that permit long diapause are probably precise and may not be reflected in recognised qualities of habitat. The species may also be present despite a perceived absence in autumn, the standard period for monitoring. Assessments of the prevalence of the life-cycle and its contribution to the persistence of E. aurinia are required. Populations of E. aurinia are known to fluctuate greatly and do occur below the observation threshold for long periods. [ABSTRACT FROM AUTHOR]

Abstract We illustrate an evolutionary host shift driven by increased fitness on a novel host, despite maladaptation to it in six separate host‐adaptive traits. Here, local adaptation is defined as possession of traits that provide advantage in specific environmental contexts; thus individuals can have higher fitness in benign environments to which they are maladapted than in demanding environments to which they are well adapted. A population of the butterfly Euphydryas editha adapted to a long‐lived, chemically well‐defended host, Pedicularis, had traditionally been under natural selection to avoid the ephemeral, less‐defended Collinsia. The lifespan of Collinsia was so short that it senesced before larvae entered diapause. After logging killed Pedicularis in clear‐cut patches and controlled burning simultaneously extended Collinsia lifespan, insect fitness on Collinsia in clearings suddenly became higher than on Pedicularis in adjacent unlogged patches. Collinsia was rapidly colonized and preference for it evolved, but insects feeding on it retained adaptations to Pedicularis in alighting bias, two aspects of postalighting oviposition preference, dispersal bias, geotaxis, and clutch size, all acting as maladaptations to Collinsia. Nonetheless, populations boomed on Collinsia in clearings, creating sources that fed pseudosinks in unlogged patches where Pedicularis was still used. After c. 20 years, butterfly populations in clearings disappeared and the metapopulation reverted to Pedicularis‐feeding. Here we show, via experimental manipulation of oviposition by local Pedicularis‐adapted and imported Collinsia‐adapted butterflies, that the highest survival at that time would have been from eggs laid in clearings by butterflies adapted to Collinsia. Second highest were locals on Pedicularis. In third place would have been locals on Collinsia in clearings, because local females maladaptively preferred senescent plants. Collinsia had been colonized despite maladaptation and, after successional changes, abandoned because of it. However, the abandoned Collinsia could still have provided the highest fitness, given appropriate adaptation. The butterflies had tumbled down an adaptive peak.

New plant pathogen invasions typified by cryptic disease symptoms or those appearing sporadically in time and patchily in space, might go largely unnoticed and not taken seriously by ecologists. We present evidence that the recent invasion of Pyrenopeziza plantaginis (Dermateaceae) into the Pacific Northwest USA, which causes foliar necrosis in the fall and winter on Plantago lanceolata (plantain), the primary (non-native) foodplant for six of the eight extant Taylor’s checkerspot butterfly populations (Euphydryas editha taylori, endangered species), has altered eco-evolutionary foodplant interactions to a degree that threatens butterfly populations with extinction. Patterns of butterfly, larval food plant, and P. plantaginis disease development suggested the ancestral relationship was a two-foodplant system, with perennial Castilleja spp. supporting oviposition and pre-diapause larvae, and the annual Collinsia parviflora supporting post-diapause larvae. Plantain, in the absence of P. plantaginis disease, provided larval food resources throughout all butterfly life stages and may explain plantain’s initial adoption by Taylor’s checkerspot. However, in the presence of severe P. plantaginis disease, plantain-dependent butterfly populations experience a six-week period in the winter where post-diapause larvae lack essential plantain resources. Only C. parviflora, which is rare and competitively inferior under present habitat conditions, can fulfill the post-diapause larval feeding requirements in the presence of severe P. plantaginis disease. However, a germination timing experiment suggested C. parviflora to be suitably timed for only Washington Taylor’s checkerspot populations. The recent invasion by P. plantaginis appears to have rendered the ancestrally adaptive acquisition of plantain by Taylor’s checkerspot an unreliable, maladaptive foodplant interaction.

We illustrate an evolutionary host shift driven by increased fitness on a novel host, despite maladaptation to it in six separate host‐adaptive traits. Here, local adaptation is defined as possession of traits that provide advantage in specific environmental contexts; thus individuals can have higher fitness in benign environments to which they are maladapted than in demanding environments to which they are well adapted. A population of the butterfly Euphydryas editha adapted to a long‐lived, chemically well‐defended host, Pedicularis, had traditionally been under natural selection to avoid the ephemeral, less‐defended Collinsia. The lifespan of Collinsia was so short that it senesced before larvae entered diapause. After logging killed Pedicularis in clear‐cut patches and controlled burning simultaneously extended Collinsia lifespan, insect fitness on Collinsia in clearings suddenly became higher than on Pedicularis in adjacent unlogged patches. Collinsia was rapidly colonized and preference for it evolved, but insects feeding on it retained adaptations to Pedicularis in alighting bias, two aspects of postalighting oviposition preference, dispersal bias, geotaxis, and clutch size, all acting as maladaptations to Collinsia. Nonetheless, populations boomed on Collinsia in clearings, creating sources that fed pseudosinks in unlogged patches where Pedicularis was still used. After c. 20 years, butterfly populations in clearings disappeared and the metapopulation reverted to Pedicularis‐feeding. Here we show, via experimental manipulation of oviposition by local Pedicularis‐adapted and imported Collinsia‐adapted butterflies, that the highest survival at that time would have been from eggs laid in clearings by butterflies adapted to Collinsia. Second highest were locals on Pedicularis. In third place would have been locals on Collinsia in clearings, because local females maladaptively preferred senescent plants. Collinsia had been colonized despite maladaptation and, after successional changes, abandoned because of it. However, the abandoned Collinsia could still have provided the highest fitness, given appropriate adaptation. The butterflies had tumbled down an adaptive peak. [ABSTRACT FROM AUTHOR]

In the Czech Republic, the scarce fritillary (Euphydryas maturna) had been considered extinct until the rediscovery of an extant population in Dománovický les, Central Bohemia. Subsequent efforts to protect the locality were thwarted by disputes between landowners and researchers. In 2010, when the population size was reaching critically low levels, appropriate management was finally established at the locality. To evaluate the current status of the population, an intensive mark-release-recapture study was conducted in the area in 2016 and 2017, comprising several hundreds captured individuals. The total population size was estimated at 764 butterflies for 2016 and 518 butterflies for 2017. In comparison with the pilot study performed in 2002, the population size was slightly higher, but the dispersal rates were lower. These results indicate that Euphydryas maturna in the Czech Republic has managed to bounce back from a critical population size. On the other hand, the risk of extinction has not been averted due to continued habitat loss and stochastic environmental effects. Management efforts should aim to expand the habitats used by the breeding populations, at present predominantly confined to temporary forest clearings and to open canopy forest with low tree density. Moreover, assisted reintroductions of this only surviving population to the surrounding areas should be considered. [ABSTRACT FROM AUTHOR]

White-tailed Deer (Odocoileus virginianus) have been shown to be detrimental to a number of Lepidoptera. Potential host plants for specialist butterfly species can be reduced and removed from native areas through deer browsing. The Ozark Baltimore Checkerspot (Euphydryas phaeton ozarkae) is a univoltine nymphalid butterfly endemic to the Ozark regions of Arkansas, Kansas, Missouri, and Oklahoma. In the area around the Buffalo River in Arkansas, the larval host for this butterfly is Smooth Yellow False Foxglove (Aureolaria flava). We examined the timing and quantified the effect that deer foraging had on A. flava in four E. p. ozarkae populations. Browsing occurred in late spring and reduced plant availability by as much as 87% over a two-month period. Browsed plants lost an average of 44 cm in height; data show taller plants were more likely to be browsed than shorter ones. Extensive herbivory caused early-fall-active and late-spring-active larvae to contend with reduced host plant availability, which likely resulted in increased mortality. We also found that browsed plants were less likely to be selected for oviposition. The amount of plant loss appeared to be associated with deer abundance and area attributes (i.e., slope, human activity, plant density, etc.). We found that browsing by White-tailed Deer that is too intense or prolonged can have important consequences for the Ozark Baltimore Checkerspot. [ABSTRACT FROM AUTHOR]

Many insect herbivores are dietary specialists capable of sequestering the secondary metabolites produced by their host plants. These defensive compounds have important but complex implications for tritrophic interactions between plants, herbivores, and natural enemies. The sequestration of host plant secondary metabolites defends herbivores from attack by generalist predators, but may also compromise the immune response, making insect herbivores more vulnerable to parasitism. Here, we investigate the role of plant secondary metabolites in mediating interactions between a specialist herbivore and its natural enemies. The host plants are two Penstemon species, Penstemon glaber and Penstemon virgatus, which are chemically defended by iridoid glycosides (IGs). First, we examined how Penstemon iridoid glycoside content influences the sequestration of IGs by a specialist herbivore, Euphydryas anicia. Then, we performed ant bioassays to assess how host plant species influences larval susceptibility to predators and phenoloxidase assays to assess the immunocompetence and potential vulnerability to parasitoids and pathogens. We found that the concentration of IGs sequestered by E. anicia larvae varied with host plant diet. Larvae reared on P. glaber sequestered more IGs than larvae reared on P. virgatus. Yet, ant predators found larvae unpalatable regardless of host plant diet and were also repelled by sugar solutions containing isolated IGs. However, E. anicia larvae reared on P. glaber showed higher levels of phenoloxidase activity than larvae reared on P. virgatus. Our results suggest that the sequestration of some secondary metabolites can effectively protect herbivores from predation, yet may also increase vulnerability to parasitism via decreased immunocompetence. [ABSTRACT FROM AUTHOR]

Coppice and coppice with standards are important habitats for species of light forests, because regular cutting of re-growth applied in this type of forest-use produces forest structures that fulfil habitat requirements of these species. Coppicing had been a traditional forest-use system in Central Europe for centuries, but it has dramatically declined in the last 100 years. As a conservation strategy, a contract-based conservation program for forests (CBCP Forest) was introduced in 2005 in Bavaria, Germany, that supports among other activities coppiced forests. We studied the effects of CBCP Forest on the occurrence and abundance of two Lepidoptera species of European conservation concern ( Euphydryas maturna , Eriogaster catax ) as umbrella species in ten forest patches. With the introduction of the CBCP Forest no further loss of coppiced forests occurred in our study area, in contrast, a new coppiced forest was initiated. The occurrence and number of larval webs of our studied species were highest after 5–10 ( E. catax ) and 10–15 ( E. maturna ) years of cutting. This means that coppicing can maintain a dynamically changing forest where both study species can find patches of optimal age and thus coppicing ensures their long-term persistence. We also found larval webs in high forests adjoining coppiced forests, but in much lower number and larval webs occurred always around forest gaps (e.g. roads) or edges. Onset of specific management including coppicing in these high forests highly increased the occurrence of E. maturna and E. catax . The survival of the populations of E. maturna and E. catax in our study area is closely connected to the persistence of coppicing as supported by CBCP Forest. As they are considered as umbrella species for numerous inhabitants of light forests, we assume a positive effect on the whole community. CBCP Forest is a valuable conservation tool for coppices and should be actively advertised to promote greater uptake by forestry practitioners and stakeholders. [ABSTRACT FROM AUTHOR]

Context: Landscape-scale population dynamics are driven in part by movement within and dispersal among habitat patches. Predicting these processes requires information about how movement behavior varies among land cover types. Objectives: We investigated how butterfly movement in a heterogeneous landscape varies within and between habitat and matrix land cover types, and the implications of these differences for within-patch residence times and among-patch connectivity. Methods: We empirically measured movement behavior in the Baltimore checkerspot butterfly ( Euphydryas phaeton) in three land cover classes that broadly constitute habitat and two classes that constitute matrix. We also measured habitat preference at boundaries. We predicted patch residence times and interpatch dispersal using movement parameters estimated separately for each habitat and matrix land cover subclass (5 categories), or for combined habitat and combined matrix land cover classes (2 categories). We evaluated the effects of including edge behavior on all metrics. Results: Overall, movement was slower within habitat land cover types, and faster in matrix cover types. Butterflies at forest edges were biased to remain in open areas, and connectivity and patch residence times were most affected by behavior at structural edges. Differences in movement between matrix subclasses had a greater effect on predictions about connectivity than differences between habitat subclasses. Differences in movement among habitat subclasses had a greater effect on residence times. Conclusions: Our findings highlight the importance of careful classification of movement and land cover in heterogeneous landscapes, and reveal how subtle differences in behavioral responses to land cover can affect landscape-scale outcomes. [ABSTRACT FROM AUTHOR]

Many insect species sequester compounds acquired from their host plants for defense against natural enemies. The distribution of these compounds is likely to affect both their efficacy as defenses, and their costs. In this study we examined the distribution of sequestered iridoid glycosides (IGs) in two congeneric species of nymphalid butterfly, Euphydryas anicia and E. phaeton, and found that the pattern of localization of IGs differed between the two species. Although IG concentrations were quite high in the heads of both species, the relative concentrations in wings and abdomens differed substantially. Euphydryas anicia had relatively high IG concentrations in their abdomens and low IG concentrations in their wings, whereas the reverse was true in E. phaeton. We interpret these results in light of two current hypotheses regarding where sequestered chemicals should be localized: that they should be found in wings, which would allow non-lethal sampling by predators; and that their distribution is constrained by the distribution of tissue types to which sequestered compounds bind. We also offer the third hypothesis, that costs of storage may differ among body parts, and that the localization of compounds may reflect a cost-reduction strategy. Results from E. phaeton were consistent with all three of these non-mutually exclusive hypotheses, whereas results from E. anicia were only consistent with the notion that tissue bias among body parts plays a role in IG distribution. The finding that these two congeneric butterflies exhibit different patterns of IG localization suggests that they have been shaped by different selection regimes. [ABSTRACT FROM AUTHOR]

Exotic pathogen invasions can change host eco-evolutionary interactions and possibly create an evolutionary trap when the pathogen generates mismatches between developmental phenology and reproductive cues. Taylor's checkerspot butterfly ( Euphydryas editha taylori), is an endangered species of western North America with 80 % of the extant populations dependent on an exotic host, Plantago lanceolata. Survey of occupied, recently extinct, and unsuccessful butterfly reintroduction sites spanning 4° of latitude revealed widespread disease on P. lanceolata caused by Pyrenopeziza plantaginis. This fungal pathogen, new to North America, reduces the standing crop of P. lanceolata foliage throughout the winter post-diapause larval feeding period. However, disease is absent when adult butterflies and pre-diapause larvae are active. Diseased plants were frequent in Taylor's checkerspot populations with a history of persistence, but >90 % of the host plants in these populations had initiated new leaves within the first few weeks of post-diapause larval feeding. Conversely, host plants in recently extinct and unsuccessfully reintroduced populations were severely diseased, >66 % mean foliage necrosis/plant, and <23 % had initiated new leaves. Feeding choice trials with 25 larvae indicated that new leaves were strongly and consistently preferred by post-diapause larvae over all other available leaf types, both diseased and non-diseased. Because the influence of disease on post-diapause larval food resources is developmentally disassociated from oviposition, P. plantaginis invasion appears to have triggered an evolutionary trap for Plantago-dependent populations of Taylor's checkerspot. [ABSTRACT FROM AUTHOR]

Habitat modification by invasive species places numerous butterfly species at risk of extinction. Grass-specific herbicides, graminicides, are a sought-after tool to reduce invasive grasses, augment forbs and enhance butterfly populations. However, possible non-target effects raise concern. We investigated non-target effects of graminicides on three species of caterpillars in the genus Euphydryas (Nymphalidae), a taxon with numerous species in decline worldwide. In one experiment, we compared the effects of three graminicides (clethodim, sethoxydim and fluazifop-p-butyl) on E. colon. In a second experiment, we assessed the effects of fluazifop-p-butyl, the most commonly used graminicide in prairies in the Northwest USA, on three Euphydryas species ( E. colon, E. editha and E. phaeton), each raised on two different hostplants. In the first experiment, fluazifop-p-butyl did not affect survivorship of pre-diapause larvae, sethoxydim reduced survivorship by 20 % relative to controls, and effects of clethodim were inconclusive. Graminicides did not change the total concentration of iridoid glycosides in the caterpillars, but all three graminicides increased the concentration of aucubin to almost double the level in control treatments. In the second experiment, the effects of fluazifop-b-butyl were not consistent across butterfly and host plant species. However, fluazifop-b-butyl reduced group size of gregarious pre-diapause larvae under all conditions. Our results suggest that if managers use graminicides over the short-term to control invasive grasses, fluazifop-p-butyl has the most promise for minimal effects. However, efforts should be paired with demographic and behavioral monitoring to quantify context-dependent impacts. [ABSTRACT FROM AUTHOR]

In this paper, we show the results of research that can inform conservation measures elsewhere in Europe for the endangered butterfly Euphydryas aurinia. a five year field study was undertaken to identify the host plant preference of larvae of Euphydryas aurinia provincialis in the Mediterranean and which signals are used by females to lay their eggs. The females oviposit on Gentiana cruciata, Scabiosa columbaria and Cephalaria leucantha; the larvae feed on all these plants and additionally on Lonicera caprifoliumin the wild and on Gentiana lutea in the laboratory. The females do not show any preference for a specific host plant and the larvae move from one species of plant to another without any difficulty. The most important factors in determining the female oviposition are the visibility, accessibility and sun-exposure of the host plants. The vegetative state of host plants is the key factor in larval use of plants during the pre- and post-diapause period. The large-sized host plants, G. cruciata and C. leucantha, are optimal for the growth and survival of the pre-diapause I-III larval instar, while they are unavailable to the larvae in Spring because of their delayed vegetative growth. The post-diapause larvae preferentially feed on plants of S. columbaria, and to lesser degree L. caprifolium, as they provide and abundant food source compared with G. cruciata and C. leucantha. The results also suggest that, there is an evolutionary advantage in large numbers of caterpillars feeding together, with the females of E. aurinia provincialis preferring to lay their eggs nearby or above egg batches laid previously by another female, and selecting large plants for oviposition. Despite the competition for food among caterpillars, the oviposition behaviour of females is advantageous and increases the larval survival rate on large plants. The gregarious larval behaviour provides several benefits during both pre-diapause period (avoiding starvation) and post-diapause period (efficiency in thermoregulation). [ABSTRACT FROM AUTHOR]

Ecological and geographical differences between eastern and western populations of the Baltimore Checkerspot have led to a division into two subspecies, E. p. phaeton and E. p. ozarkae. Research concerning E. p. ozarkae is sparse, and prior to our work, many aspects of the life history of this subspecies were not known. An accurate assessment of its status has been hindered and confused through the use of data obtained from the eastern subspecies (e.g., mesic habitats and larval food plant) to characterize Ozark populations (e.g., glade habitats and a different larval food plant). From 2011 to 2014 we studied this butterfly in the Ozark Mountains of northern Arkansas. We identified the availability of the primary larval host plant ( Aureolaria flava) as a potential limiting factor and investigated limitations to the distribution of this plant. We found many similarities concerning the timing of development between the two subspecies but ample evidence to demonstrate the uniqueness of Ozark populations. Our findings provide valuable information for future research, management, and conservation of the Ozark Baltimore Checkerspot. [ABSTRACT FROM AUTHOR]

The Euro-Siberian Scarce Fritillary Euphydryas maturna is considered a vulnerable species in the European Union and is listed in Annexes II and IV of the Habitats Directive. The butterfly shows a complex pattern of larval plant use throughout its range. In central Europe females oviposit on some trees and bushes, especially Fraxinus spp., on which hatched larvae spend their pre-diapause phase of development feeding gregariously in conspicuous webs. However, some herbal plants are also reported in the north and east. During a study performed in the Natura 2000 area 'Dolina Biebrzy' (Biebrza Valley) in NE Poland we recorded populations showing a unique mixture of ecological characteristics. Both Fraxinus excelsior and Veronica longifolia were used as larval food plants before hibernation, and some local populations seemed to be completely dependent on the latter plant. Moreover, in the spring, at one site, we observed larvae feeding on Salix rosmarinifolia - the first host record for this plant species. The importance of our findings for conservation, as well as for the monitoring of the butterfly, is discussed. [ABSTRACT FROM AUTHOR]

1. Both the physiological efficiency (PE) hypothesis and the preference-performance (PP) hypothesis address the complex interactions between herbivores and host plants, albeit from different perspectives. The PE hypothesis contends that specialists are better physiologically adapted to their host plants than generalists. The PP hypothesis predicts that larvae perform best on the host plant preferred by ovipositing females. 2. This study tests components of both hypotheses using the specialist checkerspot, Euphydryas anicia, the generalist salt marsh caterpillar, Estigmene acrea, and host plants in the genus Penstemon, which are defended by iridoid glycosides . 3. In laboratory experiments, the generalist preferred and performed significantly better on the less well defended host plant species. This is consistent with results from a common garden experiment where the less well defended Penstemon species received more damage from the local community of generalists. Larvae of the specialist checkerspot preferred the more chemically defended species in the laboratory, but performed equally well on both hosts. However, field experiments demonstrated that adult checkerspot females preferred to oviposit on the less well defended host plant. 4. Components of the physiological efficiency hypothesis were supported in this system, as the specialist outperformed the generalist on the more iridoid glycoside-rich host plant species. There was no support for the PP hypothesis, however, as there was no clear relationship between female preference in the field and offspring performance in the laboratory. [ABSTRACT FROM AUTHOR]

In the present paper, we explore the evolution of cluster structure in closely related species in the Euphydryas aurinia complex based on morphological (wing pattern, genital armatures) and molecular (cytochrome c oxidase subunit I) characters. Male genitalia differ in the length and shape of the uncus, harpe and juxta branches, by the shape of some parts of the phallus, and by the amount of spikes on the ventral section of the valva. The main trends in the vertical distribution of the E. aurinia group are dwarfism with increasing altitude, coupled with enlargement of paler and darker-coloured elements of the wing pattern, increasing the overall contrast. Unlike the Euphydryas maturna, the E. aurinia complex forms many local populations specialized under different ecological conditions, probably affected by different evolutionary scenarios. The phylogenetic analysis of the group reveals two ecologically distinct subgroups: one associated with the boreal forest-mesophyllic meadow biome and one associated with the xeromesophyllic steppe biome. Within each group, two major ecological strategies have evolved in parallel: montane and lowland. Based on the results of the analyses, we revise the nomenclature as follows: E. aurinia pyrenesdebilis (Verity, 1928), stat. rev. (= debilis Oberthür, 1909, syn.n., nomen nudum), E. aurinia bulgarica (Fruhstorfer, 1916), stat. rev., E. aurinia provincialis (Boisduval, 1828), stat. rev. and E. beckeri (Lederer, 1853), stat. rev. The following name-bearing types are designated: neotype of Papilio aurinia Rottemburg, 1775, neotype of Papilio merope de Prunner, 1798, lectotype of Melitaea beckeri Lederer, 1853, and lectotype of Melitaea aurinia banghaasi Seitz, 1908. All name-bearing types are figured. A new subspecies, Euphydryas laeta ostracon Korb, Bolshakov, Fric, ssp.n., is described (type locality by holotype data: Kazakhstan, Vostochno-Kazakhstanskaya Oblast, Shemonaikha). [ABSTRACT FROM AUTHOR]

Determining the minimum area required to sustain populations has a long history in theoretical and conservation biology. Correlative approaches are often used to estimate minimum area requirements (MARs) based on relationships between area and the population size required for persistence or between species' traits and distribution patterns across landscapes. Mechanistic approaches to estimating MAR facilitate prediction across space and time but are few. We used a mechanistic MAR model to determine the critical minimum patch size (CMP) for the Baltimore checkerspot butterfly (Euphydryas phaeton), a locally abundant species in decline along its southern range, and sister to several federally listed species. Our CMP is based on principles of diffusion, where individuals in smaller patches encounter edges and leave with higher probability than those in larger patches, potentially before reproducing. We estimated a CMP for the Baltimore checkerspot of 0.7-1.5 ha, in accordance with trait-based MAR estimates. The diffusion rate on which we based this CMP was broadly similar when estimated at the landscape scale (comparing flight path vs. capture-mark-recapture data), and the estimated population growth rate was consistent with observed site trends. Our mechanistic approach to estimating MAR is appropriate for species whose movement follows a correlated random walk and may be useful where landscape-scale distributions are difficult to assess, but demographic and movement data are obtainable from a single site or the literature. Just as simple estimates of lambda are often used to assess population viability, the principles of diffusion and CMP could provide a starting place for estimating MAR for conservation. [ABSTRACT FROM AUTHOR]

Individual variation in movement can have important consequences for spatial population dynamics. For instance, individual variation increases leptokurtosis in dispersal distance, such that more individuals move very short and very long distances relative to a homogeneous population. We quantified individual variation in movement of the Baltimore checkerspot butterfly ( Euphydryas phaeton) to investigate its importance for two conservation-related metrics: the expected dispersal distance and the critical minimum patch size, or the smallest area within which a population can persist based on loss due to emigration. All movement parameters showed among-individual variation, with the greatest variation in move lengths and time spent resting. Correlations in among-individual movement parameters indicated that some butterflies were generally more mobile than others. We incorporated empirically estimated movement and demographic parameters into two individual-based models ( IBMs), one with homogeneity in movement among individuals, and one with heterogeneity in movement. As expected, individual variation in movement increased the leptokurtosis of lifetime movement distance; the maximum difference in distance moved was substantial (~850 m vs. ~5800 m) and is likely of significance for conservation. Individual variation also affected the critical minimum patch size, but the difference (~0.7 ha vs. ~0.5 ha) is unlikely to be ecologically significant. Notably, populations with individual variation had higher growth rates in small patches and lower growth rates in large patches, a logical consequence of increased leptokurtosis. Individual variation in movement is fairly straightforward to quantify using mixed effects models and is important for spatial population dynamics, thus we encourage its inclusion in studies of other systems. [ABSTRACT FROM AUTHOR]

Adaptive management is a framework for resolving key uncertainties while managing complex ecological systems. Its use has been prominent in fisheries research and wildlife harvesting; however, its application to other areas of environmental management remains somewhat limited. Indeed, adaptive management has not been used to guide and inform metapopulation restoration, despite considerable uncertainty surrounding such actions. In this study, we determined how best to learn about the colonization rate when managing metapopulations under an adaptive management framework. We developed a mainland-island metapopulation model based on the threatened bay checkerspot butterfly ( Euphydryas editha bayensis) and assessed three management approaches: adding new patches, adding area to existing patches, and doing nothing. Using stochastic dynamic programming, we found the optimal passive and active adaptive management strategies by monitoring colonization of vacant patches. Under a passive adaptive strategy, increasing patch area was best when the expected colonization rate was below a threshold; otherwise, adding new patches was optimal. Under an active adaptive strategy, it was best to add patches only when we were reasonably confident that the colonization rate was high. This research provides a framework for managing mainland-island metapopulations in the face of uncertainty while learning about the dynamics of these complex systems. [ABSTRACT FROM AUTHOR]

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Checkerspot butterflies in the genera Euphydryas and Chlosyne exhibit phenotypic polymorphisms along a well-defined latitudinal and elevational gradient in California. The patterns of phenotypic variation in Euphydryas chalcedona, Chlosyne palla, and Chlosyne hoffmanni suggest a mimetic relationship; in addition, the specific patterns of variation in C. palla suggest a female-limited polymorphic mimicry system ( FPM). However, the existence of polymorphic models runs counter to predictions of mimicry theory. Palatability trials were undertaken to assess whether or not the different color morphs of each species were distasteful or toxic to a generalized avian predator, the European starling ( Sturnus vulgaris). Results indicate that the black morph of E. chalcedona is distasteful, but not toxic, to predators, while the red morph is palatable. C . hoffmanni and both color morphs of C. palla are palatable to predators. Predators that learn to reject black E. chalcedona also reject black C. palla, suggesting that the latter is a FPM of the former. C. hoffmanni does not appear to be involved in this mimetic relationship. [ABSTRACT FROM AUTHOR]

Most butterfly wing patterns are proposed to be derived from a set of conserved pattern elements known as symmetry systems. Symmetry systems are so-named because they are often associated with parallel color stripes mirrored around linear organizing centers that run between the anterior and posterior wing margins. Even though the symmetry systems are the most prominent and diverse wing pattern elements, their study has been confounded by a lack of knowledge regarding the molecular basis of their development, as well as the difficulty of drawing pattern homologies across species with highly derived wing patterns. Here we present the first molecular characterization of symmetry system development by showing that WntA expression is consistently associated with the major basal, discal, central, and external symmetry system patterns of nymphalid butterflies. Pharmacological manipulations of signaling gradients using heparin and dextran sulfate showed that pattern organizing centers correspond precisely with WntA , wingless , Wnt6 , and Wnt10 expression patterns, thus suggesting a role for Wnt signaling in color pattern induction. Importantly, this model is supported by recent genetic and population genomic work identifying WntA as the causative locus underlying wing pattern variation within several butterfly species. By comparing the expression of WntA between nymphalid butterflies representing a range of prototypical symmetry systems, slightly deviated symmetry systems, and highly derived wing patterns, we were able to infer symmetry system homologies in several challenging cases. Our work illustrates how highly divergent morphologies can be derived from modifications to a common ground plan across both micro- and macro-evolutionary time scales. [ABSTRACT FROM AUTHOR]

Checkerspots (Melitaeini, Nymphalidae, Lepidoptera) are usually considered a textbook example of aposematic butterflies and several studies on Nearctic species confirm this., The responses of the avian predator, the great tit ( Parus major L., Paridae, Passeriformes), to five species of Palaearctic checkerspots and one control palatable ringlet ( Aphantopus hyperanthus L., Satyrinae, Nymphalidae, Lepidoptera) were observed., None of the tested checkerspots was attacked more often than the control palatable ringlet, which suggests that birds originating from the wild had no previous bad experiences with them. Nonetheless, certain tested butterfly species ( Melitea didyma, Esper; Melitea aurelia, Nickerl, and probably Melitea athalia, Rottemburg; Melitaeini, Nymphalidae, Lepidoptera) elicited some aversion in great tits (a long time handling them, a small portion of the body eaten, and some discomfort after ingestion)., Larvae of commonly eaten species ( Melitea diamina, Lang; Euphydryas aurinia, Rottemburg; Melitaeini, Nymphalidae, Lepidoptera) feed on plants containing secoiridoids (in contrast to the earlier mentioned protected species, which feed mostly on plants containing iridoid glycosides); therefore the efficiency of secoiridoids in the chemical protection of butterflies is discussed. [ABSTRACT FROM AUTHOR]

Globally, Euphydryas maturna is a polyphagous butterfly species. At our study sites in Italy and Germany however, the plant used for egg-laying was almost exclusively Fraxinus excelsior. Nevertheless, in Germany, two egg-batches were found on Ligustrum vulgare and one on Viburnum opulus. Females lay their egg-batches at low heights and mostly on small trees (but not <1 m). At the end of the flight season, small egg-batches are laid and we conclude that these are late batches laid by 'old females'. Egg-batches and pre-diapause larval webs are often clustered on certain trees and even leaves. This was shown to be a result of female behaviour and not of habitat quality, since the trees chosen were different in subsequent years. Individual females may return for laying further egg-batches to the place of the first egg-deposition and other females follow, since the survival of pre-diapause larvae is higher when more larval webs are on one tree. A further possible advantage during hibernation is discussed. In Italy, post-hibernation larvae form two distinct cohorts: larvae feeding on herbaceous plants ( Plantago major, P. minor, Veronica hederifolia), and larvae feeding on Fraxinus excelsior. Although the latter group starts feeding later and pupates later, it reaches the same pupation weight. At our German site, post-hibernation larvae were found almost exclusively on F. excelsior. In fact, we observed larvae searching for food on F. excelsior while the buds of this tree were still closed. We also found larvae searching for food in the herbal layer without finding suitable plants. In some areas, larvae have to wait for the buds of the ash tree to open. Our data suggest that conservation strategies for E. maturna must be site specific according to food plant use of pre- and post-hibernation larvae and habitat type. [ABSTRACT FROM AUTHOR]

High mountain ecosystems are extreme habitats for all organisms and therefore demand specific adaptations. In this context, we studied the ecology of the butterfly Euphydryas aurinia debilis in the High Tauern (Austria) and compared the obtained data against the ecology of the species in lower elevation habitats. We performed mark-release-recapture studies over the entire flight periods (end of June to end of July) in 2007 and 2008 to analyse the fundamental ecological parameters of a population. The demography of males and females was similar in both years, and no indication of typical protandry was detected. We observed a generally low dispersal of the individuals in both years, but males dispersed significantly more than females in 2008; this finding of low vagility was supported by allozyme analyses. Furthermore, butterflies survived periods of several days of continuously closed snow cover without any indication of increased mortality rates. In these three traits, this alpine population of E. aurinia apparently has ecological and physiological adaptations to the extreme requirements of high-altitude habitats and strongly deviates from the lower elevation populations. [ABSTRACT FROM AUTHOR]

Mediterranean countries like Portugal and Spain, so far characterised by extensive traditional land use over major parts of their territories, have been less affected by species losses. However, they are facing severe changes. As a model organism we chose the butterfly Euphydryas aurinia, highly threatened in Central Europe but still common at the Iberian Peninsula, for a mark-release-recapture survey in the western Algarve. We examined key factors for stabile metapopulation systems to assess the ability of long-term survival in the increasingly fragmented landscapes of the Iberian Peninsula. The density of the examined population was high (ca. 2,200 individuals/ha). However, the MRR-based proportion of individuals moving longer distance classes showed a better fit to the negative exponential function than to the inverse power function implying restricted dispersal behaviour. The orientation pattern of short distance movements (<10 m) proved to be independent from habitat structures. In contrast, longer movements (>10 m) were strongly orientated along the main habitat axes revealing the importance of internal habitat structures for the orientation of dispersing individuals. Based on these data, we discuss the severe consequences for the fauna of the Iberian Peninsula in an increasingly fragmented and monotonous landscape. [ABSTRACT FROM AUTHOR]

Both species-specific traits and landscape configuration, such as area and connectivity of habitat patches plus the character of uninhabitable matrix, affect animal movements in fragmented landscapes. Difficulties with disentangling species-specific and landscape effects have obscured comparisons among species, hindering the understanding of dispersal in metapopulations. To circumvent this complication, we performed a mark–recapture study of four related nymphalid butterflies within identical landscape and in single season. The studied species were three Melitaeinae checkerspots ( Euphydryas aurinia, Melitaea athalia, Melitaea diamina) and one Argynnini fritillary ( Brenthis ino). Applying the Virtual Migration model revealed that (1) except for mortality within habitat, model parameters differed from those found for the studied species elsewhere; (2) the three Melitaeinae species were more akin in movement parameters than the Argynnini representative (i.e., B. ino); (3) within Melitaeinae, differences between sexes were more prominent than differences among species; (4) Melitaeinae males left natal patches more readily than females, while the opposite applied to B. ino; (5) males of M. diamina and both sexes of B. ino exhibited highest values of dispersal mortality; (6) except for females of M. diamina and both sexes of B. ino, immigration and emigration scaled with area in females but not in males. Finding (1) demonstrates that geometry of habitat network affects mobility considerably and that transferring dispersal parameters across systems is unwarranted. Still, (2–6) demonstrate that within identical networks, related species follow similar dispersal patterns, suggesting that conservation scenarios suitable for a well-studied model species would suite related species as well. [ABSTRACT FROM AUTHOR]

When populations use different resources, they tend to diverge in traits that affect performance on those resources. The extent and complexity of divergence that is achieved will depend on gene flow, genetic constraints, and the character of divergent selection. We describe divergent host adaptation among Californian populations of the Melitaeine butterfly, Euphydryas editha. Divergence in seven traits created parallel phenotypic suites, each suite associated with the use of a different host species, either Collinsia torreyi or Pedicularis semibarbata. The suites involved alighting responses of adults (probably to visual stimuli), chemosensory responses to leaf surfaces, vertical positioning of adults and larvae (probably due to geotaxis), partitioning of reproductive effort among clutches, and larval performance. Remarkably, the divergent suites did not occur sympatrically, despite ubiquitous co-occurrence of the hosts, and we know of only one site where any Collinsia species is used sympatrically with another host. In contrast, E. editha often uses two host genera sympatrically when neither of them is Collinsia. We suggest that adaptation to Collinsia is incompatible with adaptation to other hosts and may generate extrinsic postzygotic reproductive isolation among populations. Despite the apparent rarity of host-shift-associated speciation in Melitaeine butterflies, adoption of Collinsia as a host may lead to allopatric ecological speciation. [ABSTRACT FROM AUTHOR]