BUSCADOR RECOLECTA

1. Phenological change is the most widely documented biological impact of climate change, but shows marked variation in magnitude among populations and species. Thus, quantifying the environmental factors and organismal differences driving this intra- and interspecific variability in phenology is vital to understand and forecast the ecological consequences of climate change.
2. Here, we test intra- and interspecific differences for a set of butterfly species in the organismal sensitivity of flight phenology and its dependence on environmental factors, using as our model system an elevation gradient in a Mediterranean mountain range where temperature and relative humidity vary substantially over space and time.
3. We use field-collected meteorological data, and butterfly counts for 20 univoltine species over 14 years, to test the relative effects on phenology of temperature and relative humidity, the sensitivity of phenology to spatial and temporal variation in temperature and whether ecological traits account for inter-specific variation
in sensitivity.
4. For all species, temperature in the months immediately preceding adult emergence had the strongest relationship with phenology. All species appeared earlier in warmer years, with those flying earlier in the season showing the greatest sensitivity to annual (temporal) variation in temperature. However, only a minority
of species showed evidence of plastic, space-for-time responses to temperature. Instead, most species showed strong evidence that phenology was more sensitive to temporal than spatial variation in temperature.
5. Our results support the dominant influence of temperature on phenology, even in Mediterranean environments suffering summer drought. They also suggest that accurate forecasts of species' phenological shifts could require the isolation of spatial from temporal components of temperature variation, because the sensitivity of populations and species may differ across these two dimensions. The factors driving synchronisation of phenology over space merit particular research in the context of climate change, given their potential to expose populations simultaneously to environmental extremes., British Ecological Society; Ministerio de Economía y Competitividad. Grant Numbers: CGL2005‐06820/BOS, CGL2008‐04950/BOS, CGL2011‐30259, CGL2014‐57784‐P, REN2002‐12853‐E/GLO; Universidad Rey Juan Carlos / Comunidad de Madrid. Grant Numbers: PEJD‐2017‐PRE/AMB‐4075, URJC‐CM‐2006‐CET‐0592; Royal Society. Grant Number: JP10052., Peer reviewed

Parasitism is a key factor in the population dynamics of many herbivorous insects, although its impact on host populations varies widely, for instance, along latitudinal and altitudinal gradients. Understanding the sources of geographical variation in host–parasitoid interactions is crucial for reliably predicting the future success of the interacting species under a context of global change.
Here, we examine larval parasitism in the butterfly Aglais urticae in south-west Europe, where it is a mountain specialist. Larval nests were sampled over 2 years along altitudinal gradients in three Iberian mountain ranges, including the Sierra Nevada, home to its southernmost European population. Additional data on nettle condition and adult butterflies were obtained in the study areas.
These data sources were used to investigate whether or not differences in parasitism rates are related to the geographical position and phenology of the host, and to the availability of the host plants.
Phenological differences in the host populations between regions were related to the severity of summer drought and the corresponding differences in host plant availability. At the trailing-edge of its distribution, the butterfly's breeding season was restricted to the end of winter and spring, while in its northern Iberian range the season was prolonged until mid-summer. Although parasitism was an important source of mortality in all regions, parasitism rates and parasitoid richness were highest in the north and lowest in the south. Moreover, within a region, there was a notable increase in parasitism rates over time, which probably led to selection against an additional late summer host generation in northern regions. Conversely, the shorter breeding season in Sierra Nevada resulted in a loss of synchrony between the host and one important late season parasitoid, Sturmia bella, which may partly explain the high density of this butterfly species at the trailing-edge of its range.
Our results support the key role of host phenology in accounting for differences in parasitism rates between populations. They also provide insights into how climate through host plant availability affects host phenology and, ultimately, the impact of parasitism on host populations., Sierra Nevada fieldwork was partly supported by the Global Change Observatory of Sierra Nevada that is funded by the Andalusian Government (Ministry of Agriculture, Livestock, Fisheries and Sustainable Development) with the collaboration of the University of Granada. Funding for this research was provided by Ministerio de Ciencia e Innovación, R + D Programa Nacional, Proyecto I + D + I (grant CGL2014-57784-P to D.G.)., Peer reviewed

© 2024 The Authors. Molecular Ecology published by John Wiley & Sons Ltd. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes., Glacial cycles lead to periodic population interbreeding and isolation in warm-adapted species, which impact genetic structure and evolution. However, the effects of these processes on highly mobile and more cold-tolerant species are not well understood. This study aims to shed light on the phylogeographic history of Aglais urticae, a butterfly species with considerable dispersal ability, and a wide Palearctic distribution reaching the Arctic. Through the analysis of genomic data, four main genetic lineages are identified: European, Sierra Nevada, Sicily/Calabria/Peloponnese, and Eastern. The results indicate that the Sardo-Corsican endemic taxon ichnusa is a distinct species. The split between the relict lineages in southern Europe and the main European lineage is estimated to have happened 400¿450 thousand years ago, with admixture observed during the Quaternary glacial cycles, and still ongoing, albeit to a much smaller extent. These results suggest that these lineages may be better treated as subspecific parapatric taxa. Ecological niche modelling supported the existence of both Mediterranean and extra-Mediterranean refugia during the glacial periods, with the main one located on the Atlantic coast. Nevertheless, gene flow between populations was possible, indicating that both differentiation and admixture have acted continuously across glacial cycles in this cold-tolerant butterfly, generally balancing each other but producing differentiated lineages in the southern peninsulas. We conclude that the population dynamics and the processes shaping the population genetic structure of cold-adapted species during the Quaternary ice ages may be different than those classically accepted for warm-adapted species., This research was supported by grants PID2019-107078GB-I00 and PID2022-139689NB-I00 (funded by Ministerio de Ciencia e Innovación (MCIN)/Agencia Estatal de Investigación (AEI)/10.13039/501100011033 and ERDF A way of making Europe) and by grant 2021-SGR-00420 from Departament de Recerca i Universitats de la Generalitat de Catalunya to RV, by grant CGL2014-57784-P funded by MCIN/AEI/10.13039/501100011033 to DG, by PRE2020-094870 funded by MCIN/AEI/10.13039/501100011033 and ‘European Social Fund (ESF) Investing in your future’ to VM, and by BES-2017-080641 funded by MCIN/AEI/10.13039/501100011033 and by ‘ESF Investing in your future’ to JCH. L.D. acknowledges the support of NBFC to University of Florence, Department of Biology, funded by the Italian Ministry of University and Research, PNRR, Missione 4 Componente 2, ‘Dalla ricerca all'impresa’, Investimento 1.4, Project CN00000033 and by several projects with the Direttiva Biodiversità of the Italian Environmental Ministry. G.T. was supported by grant PID2020-117739GA-100 funded by Ministerio de Ciencia e Innovación (MCIN)/Agencia Estatal de Investigación (AEI)/10.13039/501100011033 and by grant 2021-SGR-01334 from Departament de Recerca i Universitats de la Generalitat de Catalunya., Abstract1 INTRODUCTION2 MATERIALS AND METHODS2.1 Sampling2.2 ddRADseq library preparation2.3 Data processing2.4 Population genetic structure2.5 Phylogenetic inference and gene flow analyses2.6 Genetic diversity analyses2.7 Demographic history2.8 Ecological niche modelling (ENM)2.9 Wolbachia infection analysis3 RESULTS3.1 Principal component analysis3.2 Genetic structuring and hybridization between lineages3.3 Phylogenetic inference3.4 Gene flow analyses3.5 Genetic diversity analyses3.6 Demographic history3.7 Ecological niche modelling3.8 Wolbachia infection analysis4 DISCUSSION4.1 Genomic data clarify previous mitochondrial results4.2 Evidence of admixture4.3 Genetic diversity4.4 The opposed forces of differentiation by isolation and admixture by gene flow4.5 A complex scenario of differentiation with gene flowAUTHOR CONTRIBUTIONSACKNOWLEDGEMENTSCONFLICT OF INTEREST STATEMENT, Peer reviewed

Au_filtered_PCA.vcf - used as input for PCA, Au_STRUCTURE.str - used as input for STRUCTURE analysis, Au_IQTREE.phy - used as input for phylogenetic inference in IQTREE, Au_PhyloNetworks.loci - used as input to create gene trees for subsequent use in PhyloNetworks analysis, Au_filtered_TreeMix.vcf - used as input for TreeMix analysis, Au_TASSEL_western.vcf; Au_TASSEL_eastern.vcf; Au_TASSEL_central.vcf - used as input for genetic diversity analysis in TASSEL, Au_filtered_dadi.vcf - used to produce SFS file for dadi analysis, Au_EuSicily_hybridsim; Au_EuSierra_hybridsim - used to simulate hybrids with HYBRIDLAB, Peer reviewed

Au_filtered_dadi.vcf - used to produce SFS file for dadi analysis, Au_EuSicily_hybridsim; Au_EuSierra_hybridsim - used to simulate hybrids with HYBRIDLAB, Peer reviewed

Au_filtered_PCA.vcf - used as input for PCA, Au_STRUCTURE.str - used as input for STRUCTURE analysis, Au_IQTREE.phy - used as input for phylogenetic inference in IQTREE, Au_PhyloNetworks.loci - used as input to create gene trees for subsequent use in PhyloNetworks analysis, Au_filtered_TreeMix.vcf - used as input for TreeMix analysis, Au_TASSEL_western.vcf; Au_TASSEL_eastern.vcf; Au_TASSEL_central.vcf - used as input for genetic diversity analysis in TASSEL, Peer reviewed