Successful Conservation of a Threatened Maculinea Butterfly
ABSTRACT Globally threatened butterflies have prompted research-based approaches to insect conservation. Here, we describe the reversal of the decline of Maculinea arion (Large Blue), a charismatic specialist whose larvae parasitize Myrmica ant societies. M. arion larvae were more specialized than had previously been recognized, being adapted to a single host-ant species that inhabits a narrow niche in grassland. Inconspicuous changes in grazing and vegetation structure caused host ants to be replaced by similar but unsuitable congeners, explaining the extinction of European Maculinea populations. Once this problem was identified, UK ecosystems were perturbed appropriately, validating models predicting the recovery and subsequent dynamics of the butterfly and ants at 78 sites. The successful identification and reversal of the problem provides a paradigm for other insect conservation projects.
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ABSTRACT: Populations close to species distribution limits often differ in their habitat use from more central populations of the species distribution. Knowledge of species ecology derived from the latter may therefore not be sufficient to ensure successful conservation of peripheral populations.In this study, we examine habitat use of Phengaris (=Maculinea) arion (Lepidoptera, Lycaenidae), an endangered myrmecophilous butterfly, in populations close to its northern distribution limit (in Estonia). A particular emphasis is given to its interactions with other species – host plant and host ant use, and, as a novel aspect, adult predation by dragonflies.Phengaris arion was found to be restricted to grassland patches with much higher host plant abundance than shown in other regions and predicted by habitat suitability models.All direct observations of the host ant use of P. arion were limited to the colonies of Myrmica lonae, an ant species which has nowhere else been demonstrated to be the primary host of this butterfly. Our data thus contribute to the emerging understanding that host ant use in P. arion can be geographically remarkably diverse.The results indicate that dragonfly predation on adult butterflies could be an essential driver of patch occupancy in P. arion. Our findings thus suggest that top-down influences, largely neglected in butterfly conservation, may actually need to be considered.Insect Conservation and Diversity 05/2015; DOI:10.1111/icad.12104 · 1.94 Impact Factor
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ABSTRACT: As part of a major transformation of the EU agriculture in the last few decades, traditional land-use types disappeared due to either intensification or abandonment. Grasslands are highly affected in this process and are consequently among the most threatened semi-natural habitats in Europe. However, experimental evidence is scarce on the effects of management types on biodiversity. Moreover, management types need to be feasible within the recently changed socio-economic circumstances in Hungary. We investigated the effects of timing and frequency of mowing on the abundance of the scarce large blue butterfly (Phengaris teleius), on the abundance of its host plant and on the frequency of its host ant species. In each of four study meadows, we applied four types of management: one cut per year in May, one cut per year in September, two cuts per year (May and September) and cessation of management. After three years of experimental management, we found that adult butterflies preferred plots cut once in September over plots cut twice per year and abandoned ones, while plots cut once in May were also preferred over abandoned plots. Relative host plant abundance remarkably increased in plots cut once in September. Management did not affect the occupancy pattern of Myrmica host ants. Invasive goldenrod was successfully retained by two cuts per year. To our knowledge, this is the first attempt to test management effects on the whole community module of a socially parasitic butterfly, its host plant and host ants. Based on the results, we provide recommendations on regional management of the scarce large blue's habitats.Agriculture Ecosystems & Environment 10/2014; 196:24–33. DOI:10.1016/j.agee.2014.06.019 · 3.20 Impact Factor
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ABSTRACT: Separating out the abiotic and biotic processes (such as limiting similarity or environmental filtering) from stochastic processes is central to developing a cogent approach for understanding patterns in ecological community structure and organization. Using butterfly communities in a fragmented landscape, we tested the hypothesis that local environmental filtering drives character convergences in traits of species belonging to different clades. We found that, while many traits were determined both by phylogeny and environment, trait convergence within the phylogeny was extensive and eroded the phylogenetic structure associated with habitat use. Traits associated with habitat use are shown to be only moderately phylogenetically conserved in chalk grassland butterfly assemblages, and further analysis revealed that traits associated with environmental filtering may be highly labile rather than phylogenetically conserved. In general, a significant phylogenetic signal is therefore neither sufficient to demonstrate a lack of trait convergence, nor to determine whether communities are likely to be phylogenetically structured. We conclude that explicit trait-based approaches should be used in preference to the more indirect approach based on phylogenetic conservatism for understanding metacommunity assembly processes.Ecology 06/2014; 95(12). DOI:10.1890/13-2036.1 · 5.00 Impact Factor