Marsh Fritillary Euphydryas Aurinia Research Articles

Moderate mobility and high density in a small area: the population ecology of the marsh fritillary Euphydryas aurinia in Transylvania (Romania).

The Natura 2000 network is one of the most important tools for nature conservation in the EU. Therefore, knowledge of the ecology of the species listed on the Habitats Directive annexes is of particular relevance. One of these species is the butterfly Euphydryas aurinia. Much is already known about the ecology of this species at the European level, but information on Romania is scarce. Therefore, in a study area northwest of Cluj, the species was intensively studied in a mark-release-recapture study over its entire flight period. The investigated population harboured many individuals and had a high density. The dispersal behaviour of the individuals was somewhat more pronounced than in Mediterranean and partly also high alpine populations, but roughly comparable to other populations of the nominotypic subspecies. Overall, the ecological differences to Central and Western European populations were not very pronounced, and many of the conservation-relevant statements on this species in Central Europe should also be largely valid in Romania.

The dark side of the Common Agricultural Policy

The dark side of the Common Agricultural Policy

Gene-flow within a butterfly metapopulation: the marsh fritillary Euphydryas aurinia in western Bohemia (Czech Republic)

In human-altered landscapes, species with specific habitat requirements tend to persist as metapopulations, forming colonies restricted to patches of suitable habitats, displaying mutually independent within-patch dynamics and interconnected by inter-colony movements of individuals. Despite intuitive appeal and both empirical and analytical evidence, metapopulations of only relatively few butterfly systems had been both monitored for multiple years to quantify metapopulation dynamics, and assayed from the point of view of population genetics. We used allozyme analysis to study the genetic make-up of a metapopulation of a declining and EU-protected butterfly, Euphydryas aurinia, inhabiting humid grasslands in western Czech Republic, and reanalysed previously published demography and dispersal data to interpret the patterns. For 497 colony x year visits to the 97 colonies known at that time, we found annual extinction and colonisation probabilities roughly equal to 4%. The genetic diversity within colonies was intermediate or high for all assessed parameters of population genetic diversity and hence higher than expected for such a habitat specialist species. All the standard genetic diversity measures were positively correlated to adult counts and colony areas, but the correlations were weak and rarely significant, probably due to the rapid within-colony population dynamics. Only very weak correlations applied to larval nests numbers. We conclude that the entirety of colonies forms a well-connected system for their majority. Especially in its core parts, we assume a metapopulation structure with a dynamic equilibrium between local extinction and recolonization. It is vital to conserve in particular these structures of large and interconnected colonies.Implications for insect conservation: Conservation measures should focus on considering more in depth the habitat requirements of E. aurinia for management plans and on stabilisation strategies for colonies, especially of peripheral ones, e.g. by habitat restoration.

Caterpillars of the marsh fritillary butterfly Euphydryas aurinia can extend their life-cycle in Scotland

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.

Extreme weather affects colonization–extinction dynamics and the persistence of a threatened butterfly

Abstract Extreme weather events can be expected to increase in frequency in the future. Our knowledge on how this may affect species persistence is, however, very limited. For reliable projections of future persistence we need to understand how extreme weather affects species' population dynamics. We analysed the effect of extreme droughts on the host plant Succisa pratensis, colonization–extinction dynamics, and future persistence of the threatened marsh fritillary Euphydryas aurinia. Specifically, we studied a metapopulation inhabiting a network of 256 patches on Gotland (Sweden), where the summer of 2018 was the driest ever recorded. We analysed how the frequency and leaf size of host plants changed between 2017 and 2019, based on 6,833 records in 0.5‐m2 sample plots. Using turnover data on the butterfly from 2018 to 2019 we modelled local extinction and colonization probabilities. Moreover, we projected future population dynamics with an increasing frequency of extreme years under three different management strategies that regulate the grazing regime. Our results show a substantial decrease in both frequency (46%) and size (20%) of host plants due to the drought, which taken together may constitute a 57% loss of food resources. The butterfly occupancy decreased by over 30% between 2018 and 2019 (from 0.36 to 0.27). The extinction probability increased with increasing ‘effective area’ of the patch (taking quality reduction due to grazing into account), and the colonization probability increased with increasing connectivity and ground moisture. Projections of future dynamics showed an increasing risk of metapopulation extinction with increasing frequency of years with extreme droughts. The risk, however, clearly differed between management strategies. Less grazing in years with droughts decreased the extinction risk considerably. Synthesis and applications. Extreme weather events can have profound negative impacts on butterflies and their host plants. For the marsh fritillary, an increased frequency of extreme droughts can lead to extinction of the entire metapopulation, even in a large and seemingly viable metapopulation. Increased grazing, due to fodder deficiency in dry years, may lead to cascading negative effects, while active management that reduce grazing in years with droughts can almost completely mitigate these effects.

Microhabitat selection by ovipositing females and pre-diapause larvae of a Welsh population of Euphydryas aurinia (Lepidoptera: Nymphalidae)

Habitat requirements of the marsh fritillary Euphydryas aurinia have been studied intensively in recent years in order to inform conservation action on this rapidly declining species. Autecological studies have been undertaken on various spatial scales to account for differences in mobility between life stages. It has become clear that resource utilisation by the species varies between different geographic areas and also on a local scale. We studied the microhabitat surrounding Succisa pratensis plants chosen for oviposition and around resulting larval webs in a key Welsh population, UK. Microhabitat preferences were shown to differ between ovipositing females and pre-diapause larval groups. For oviposition, females showed a preference for host plants within clusters of S. pratensis surrounded by a relatively low sward. In contrast, larval webs were found in relatively high vegetation with relatively low S. pratensis cover in the immediate vicinity. The marked difference between oviposition and larval web microhabitat was achieved through very long distance dispersals undertaken by the pre-diapause larval groups. This gives rise to questioning the common assumption that pre-diapause larval web location can be used as a proxy for oviposition location. It also underpins the importance of managing E. aurinia habitats for maximum structural variability on a small scale.

Deraeocoris schach, a new predator of Euphydryas aurinia and other heteropteran feeding habits on caterpillar web (Heteroptera: Miridae; Lepidoptera: Nymphalidae)

In this paper, preliminary results on a field study aiming to identify predators of the Marsh Fritillary<em> Euphydryas aurinia</em> (Rottemburg, 1775) in Central Italy are presented. Several heteropterans were found on the larval nests of <em>E. aurinia</em> for dietary reasons: <em>Deraeocoris schach</em> (Fabricius, 1781) that is a predator of Marsh Fritillary larvae, <em>Palomena prasina</em> (Linnaeus, 1761) and <em>Spilostethus saxatilis</em> (Scopoli, 1763) that feed on the droppings of larvae; <em>Graphosoma lineatum</em> <em>italicum</em> (Müller, 1766) that visits the larval web during winter diapause.

Butterflies on the brink: habitat requirements for declining populations of the marsh fritillary (Euphydryas aurinia) in SW England

1. The marsh fritillary Euphydryas aurinia is one of our most endangered butterflies, and the only to be protected under European legislation as well as British. It persists in fragile subpopulations threatened by habitat fragmentation and degradation. 2. A combination of swaling and cattle grazing are accepted to be best practice for managing wet, unimproved grasslands—the favoured habitat for E. aurinia in Cornwall. These two well-endorsed methods of management were used to increase and improve the quality of habitat for E. aurinia over a 5 years period, 2004–2008, at a stronghold network of habitat patches in mid Cornwall, south-west England. 3. Analyses of adult and larval densities over 5 years in fifty-four transects across nine sites found E. aurinia to favour habitat patches with higher densities of the larval food plant (Devil’s-bit scabious Succisa pratensis), higher sward height in autumn, and intermediate optimum levels of stock grazing. 4. Main findings indicated most sites experienced significant declines in numbers. Unfavourable weather in the last 2 years of monitoring was likely to have had a significant impact on the response of individual subpopulations to habitat management though poor recovery rates may also reflect a time-lag in colonisation events after habitat improvement has occurred. 5. Habitat management produced an improvement, albeit an inconsistent improvement in habitat variables across patches—S. pratensis shows a clear recovery at some sites. Autumn sward height increased significantly at one site, and a quadratic relationship between stock grazing and important habitat variables has been found which will aid further improvement over all sites for the long term persistence of E. aurinia.

Food plant density, patch isolation and vegetation height determine occurrence in a Swedish metapopulation of the marsh fritillary Euphydryas aurinia (Rottemburg, 1775) (Lepidoptera, Nymphalidae)

The occurrence pattern of the marsh fritillary was studied within a patch network on the Baltic island Oland, Sweden. Presence/absence was established for potentially suitable habitat patches (n = 158) on calcareous moist grassland and analyzed in a multiple logistic regression model where patch area, patch isolation and nine habitat quality variables were included as explanatory variables. Larval food plant density was positively, and patch isolation negatively, correlated to the presence of Euphydryas aurinia. Area did not contribute to the explanation of the occurrence pattern. Significant interactions between larval food plant density times patch isolation, and larval food plant density times vegetation height, show that with low food plant density the butterfly primarily occurs in patches with a vegetation height of 4–10 cm, within a distance of 250 m from nearest occupied patch. In patches with a high food plant density the butterfly occurs in patches where the vegetation height is higher, 4–16 cm, and the distance to nearest occupied patch can be longer, up to 1.4 km. This study supports earlier findings in other regions, suggesting that a network of adjacent patches with a high food plant density and a vegetation height within the preferred threshold, despite their size, is an apparent conservation goal.

<i>Picromerus bidens</i> (Heteroptera: Pentatomidae) as predator of the Checkerspot <i>Euphydryas aurinia</i> (Lepidoptera: Nymphalidae)

The predatory bug Picromerus bidens is reported as a regular predator of the Marsh Fritillary Euphydryas aurinia from the region of western Bohemia, Czech Republic. Adult bugs attack pre-diapause larvae, either exposed or hidden in protective silken webs, and exhibit efficient behaviour, including returning to previously attacked webs. We observed predation in six out of 28 and eleven out of 21 local populations in 2003 and 2004, respectively. In addition, we observed two attacks by nymphs on handicapped adult butterflies. Predation of Melitaeinae by Heteroptera seems to be a widespread phenomenon, and P. bidens can act as a substantial mortality factor in small colonies of E. aurinia.

A review of the distribution, ecology and status of the marsh fritillary Euphydryas aurinia Rottemburg, 1775 (Lepidoptera: Nymphalidae) in Ireland : T. A. Lavery, Irish Naturalists' Journal, 24(5), 1993, pp 192–199

The status of the marsh fritillary in Ireland is re-assessed, based on comparison between pre and post 1980 distribution data and consideration of what is now known of the biology of this butterfly in Ireland. It is concluded that E. aurinia cannot realistically be regarded as a threatened species in Ireland but that man-induced habitat loss and habitat modification which have caused its decrease elsewhere in Europe are occurring in Ireland. It is recommended that consideration be given to protection of the few Irish sites supporting very large populations of this species, currently regarded as internationally threatened. Attention is drawn to the need for better data on present site management where large populations occur in Ireland and for more information on the controlling effects of predation and parasitization. It is suggested that re-assessment of the international status of this species would be appropriate. The marsh fritillary Euphydryas aurinia (Rott.) is an attractive butterfly associated with certain types of old pasture in Ireland. In various parts of Europe its distribution and abundance have declined noticeably during the latter part of the 20th century, resulting in its recognition as an internationally threatened species. In the present account, the biology and status of E. aurinia in Ireland are reviewed, using an extended data sheet format. The biological data are derived from direct observation by the author and others on Irish populations of this butterfly. The distribution data are