Myrmecophilous organisms have evolved in several arthropod lineages, developing specialized traits to communicate with ants. In butterflies, these include morphological, visual, chemical, behavioral, and acoustic adaptations. While acoustic communication has long been overlooked, recent studies show that vibrational signals mediate key aspects of caterpillar-ant interactions. Yet, no study has specifically investigated the rhythmic structure of such signals in myrmecophilous contexts, despite growing evidence that rhythm is a fundamental component of signal architecture across taxa. We examine the rhythmic properties of vibroacoustic signals from two ant and nine butterfly species differing in myrmecophily degree. We tested whether rhythmic features such as pulse train tempo, intertrain interval, and rhythmic patterns vary across taxa and reflect the strength of their ecological association with ants. Our results reveal that ants and highly myrmecophilous species share a complex rhythmic organization (isochrony and double meter), likely reflecting convergent adaptation to tight mutualistic interactions. Species with intermediate or no myrmecophily associations showed more variable or simplified rhythms. Temporal regularity and precision could possibly balance the need for signal recognizability with energetic constraints and avoidance of detection by unintended receivers. These findings highlight the role of temporal patterning in vibroacoustic communication, influencing signal efficiency and recognition in ant-butterfly interactions.

Abstract The introduction of alien species into new habitats stands as a pressing economic and ecological challenge but it is also essential for unveiling evolutionary processes. The introduction of the Argentine ant ( Linepithema humile ) led to the spread of a single supercolony through different continents and thousands of kilometres like in Europe, from Northwest Spain to Greece. It was assumed that the high invasiveness of the species mainly relied on the lack of agonism among colonies, an effect derived from its introduction. However, recent studies suggest that local adaptations and evolutionary divergence could involve the disruption of the Argentine ant “empire” into a mosaic of competitive colonies. We investigated how isolation affects population divergence by comparing mainland and island populations in two distant regions colonized in Spain and in Greece with morphology, agonism, cuticular hydrocarbons, and genetic diversity of ant workers. Our results showed that all colonies sampled belonged to the most spread supercolony in Europe (main supercolony) except one sampled in Crete (Heraklion; Greece), which resulted to be a supercolony not registered in Europe. The Heraklian supercolony showed a different chemical and genetic profile and hostile agonism towards the other Greek colonies. Differences between islands and mainland colonies belonging to the main supercolony were higher in Galiza than in Greece. Surprisingly, the chemical profile of the Cretan colony belonging to the main supercolony showed more similarity with the Galizan colonies than with the Greek mainland, suggesting that L. humile may have been introduced into Greece through this island instead of the mainland. Our study suggests that local adaptations in Argentine ant colonies can trigger competition between colonies. Our data strongly support the existence of a candidate supercolony which highlights either ongoing introductions of L. humile in Europe or gaps in our understanding of its metapopulation dynamics.

Coevolutionary interactions between parasites and hosts are key drivers of biological adaptation. In this study, we explore the evolutionary response of the social parasitic butterfly Phengaris teleius to its host ant, Myrmica scabrinodis , taking advantage of a unique opportunity: the reintroduction of the butterfly in the Netherlands thirty years ago. We compared the degree of host mimicry and behavioural performance of caterpillars between the reintroduced and the Polish source population. After about thirty generations, chemical and vibroacoustical signal profiles have diverged. Chemical mimicry remained limited during the pre-adoption phase for both groups; however, in the post-adoption phase, the source population showed significantly higher chemical similarity to their local hosts. In contrast, reintroduced pre-adoption caterpillars evolved vibroacoustic signals closely resembling local hosts, also resulting in a stronger response from their local host ants. This suggests that adoption is driven by acoustics and subsequently serves as a selective filter promoting post-entry chemical refinement. Behavioural data evince that despite the differences between the different communication channels, the combination of signals remains sufficient to ensure recognition and integration in both host-parasite systems. These results illustrate how social parasites involved in multisensory mimicry can rapidly recalibrate strategies to remain functional in new ecological contexts.

Our understanding of the spread of yeasts in natural ecosystems remains somewhat limited. The recent momentum of yeast ecology research has unveiled novel habitats and vectors that, alongside human activities, impact yeast communities in their natural environments. Yeasts, as non-airborne microorganisms, rely on animal vectors, predominantly insects. However, the overlooked actor in this interplay is the environmental matrix, a player potentially influencing yeast populations and their vectors. This study aims to delve deeper into the intricate, multi-layered connections between yeast populations and ecosystems, focusing on the interactions between the attributes of the environmental matrix, arthropod diversity, and the mycobiota within a renowned yeast-inhabited framework: the vineyard. To investigate these relationships, we sampled both invertebrate and yeast diversity in six organic and conventional vineyards described in terms of management and landscape composition. We identified 80 different invertebrate taxa and isolated 170 yeast strains belonging to 18 species. Notably, new species-specific yeast-insect associations were observed, including the exclusive association between Candida orthopsilosis and Hymenoptera and between Metschnikowia pulcherrima and Coleoptera. These newly identified potential associations provide valuable insights into insect and yeast physiology, hence holding the promise of enhancing our understanding of yeast and arthropod ecology and their collective impact on overall ecosystem health.

Ant evolutionary success depends mainly on the coordination of colony members, who recognize nestmates based on the cuticular hydrocarbon (CHC) profile of their epicuticle. While several studies have examined variations in this crucial factor for colony identity, few have investigated the anthropic impact on CHC profiles, and none have focused on Lasius paralienus. Here, we surveyed the changes in L. paralienus CHC assemblages across agroecosystems and assessed whether different vineyard management influences these profiles. Soil sampling within ant nests and in close surroundings was performed to measure microhabitat variations. Our results show that the cuticular chemical composition of Lasius paralienus is mainly affected by the differences between areas, with an existing but unclear anthropic influence on them. Normalized soil respiration partially explains these interarea variations. Irrespective of the conventional or organic management, human activities in agroecosystems mostly impacted L. paralienus linear alkanes, a specific class of CHCs known to play a major role against dehydration, but also affected the abundance of compounds that can be pivotal for maintaining the colony identity. Our findings suggest that vineyard practices primarily affect features of the ant cuticle, potentially enhancing microclimate adaptations. Still, the potential effects as disruptive factors need further investigation through the implementation of behavioral bioassays.

A successful reintroduction of Phengaris teleius performed in the Netherlands by translocating 86 individuals from a Polish metapopulation in 1990 represents a unique opportunity to study changes in butterflies from a source and reintroduced metapopulation after such a common conservation practice. Using multilevel comparisons, we tested morphological and genetic changes that occurred after 30 generations since the reintroduction. We also assessed the climatic and connectivity changes that occurred over time in both metapopulation networks. Unexpectedly, we found more significant morphological changes in the current individuals from the source metapopulation, where both sexes had bigger hindwings with different shapes in comparison to the individuals from the original metapopulation in the year of the reintroduction and the ones from the current reintroduced metapopulation. The butterflies from the Dutch metapopulation also had smaller thorax width compared to the ones from the current source metapopulation. The observed morphological changes can be shaped by various factors like changes in climatic conditions and habitat connectivity. Additionally, the genetic analysis revealed a differentiation between the source and reintroduced metapopulation. We found a loss of half of the allelic richness and a bottleneck effect in the reintroduced metapopulation compared to the current Polish one. Our results show that Phengaris butterflies have the potential to adapt to new habitats and respond to climatic changes despite their complex life cycle. A proper long-term habitat management in reintroduced butterfly metapopulations and habitat restoration are key factors influencing the success of reintroduction.

We briefly analyse the history of Queen Ulrika’s and of Linnaeus’ butterfly collections. We show that the type materials of some species were likely moved from Queen Ulrika’s to Linnaeus’ collection before 1803. We provide evidence that Honey and Scoble (2001) correctly designated the lectotypes of 101 of the 159 species listed in Linnaeus’ (1764) publication. We likewise conclude that, although it did not respect of the prevailing concept of the species, the lectotype of Papilio hermione was validly designated by Kudrna (1977); consequently, the neotype of P. hermione designated by Russell and Vane-Wright (2024) is invalid.

Bees (Anthophila) are among the most effective pollinators in nature being responsible for approximately one-third of the total crop pollination for human dietary supply. The interaction between plants and bees plays here an essential role and may also include vibro-acoustic signals as an important medium of information transmission. Plants have been shown to respond to airborne acoustic signals of flying pollinators by increasing the sugar concentration in the nectar. Yet very little is known about the pollinators' vibro-acoustic signatures and plant-relevant effective traits of the signal. Here we present an analysis framework of acoustic signals for three different bee species, namely Rhodanthidium sticticum, Amegilla quadrifasciata, and Apis mellifera, recorded in the rural areas (Chera, Chulilla, and Macastre) of the Province of Valencia, Spain, visiting Antirrhinum (snapdragon) plants. First, from audio-visual recordings, audio signals for different bee behaviours during visits were identified. We showed that periodogram and recurrence-based spectrograms could be used to classify real-life bioacoustic data recorded outdoors. This approach can also be used to predict future data sets for which a traditional approach like spectral analysis is unsuitable, especially for noisy, more nonlinear, and complex data.

Changes in habitat characteristics are known to have profound effects on biotic communities and their functional traits. In the context of an urban-rural gradient, urbanisation drastically alters abiotic characteristics, e.g., by increasing environmental temperatures and through light pollution. These abiotic changes significantly impact the functional traits of organisms, particularly insects. Furthermore, changes in habitat characteristics also drive changes in the behavioural traits of animals, allowing them to adapt and thrive in new environments. In our study, we focused on the synanthropic ant species Lasius niger as a model organism. We conducted nocturnal field observations and complemented them with laboratory experiments to investigate the influence of night warming (NW) associated with Urban Heat Islands (UHI), light pollution (ALAN), and habitat type on ant foraging behaviour. In addition, we investigated the influence of elevated temperatures on brood development and worker mortality. Our findings revealed that urban populations of L. niger were generally more active during the night compared to their rural counterparts, although the magnitude of this difference varied with specific city characteristics. In laboratory settings, higher temperatures and continuous illumination were associated with increased activity level in ants, again differing between urban and rural populations. Rural ants exhibited more locomotion compared to their urban counterparts when maintained under identical conditions, which might enable them to forage more effectively in a potentially more challenging environment. High temperatures decreased the developmental time of brood from both habitat types and increased worker mortality, although rural colonies were more strongly affected. Overall, our study provides novel insights into the influence of urban environmental stressors on the foraging activity pattern and colony development of ants. Such stressors can be important for the establishment and spread of synanthropic ant species, including invasive ones, and the biotic homogenization of anthropogenic ecosystems.

The parasitic relationship between Maculinea butterflies and Myrmica ants has been extensively studied but little information is available on the spatial occurrence of Maculinea larvae. We searched for the presence of Maculinea teleius in 211 ant nests at two sites in two crucial phases of its life cycle, i.e., in autumn, during the initial larval development, and in the following late spring, before pupation. We assessed variations in the proportion of infested nests and factors correlated with spatial distributions of parasites in Myrmica colonies. The parasitism rate in autumn was very high (∼50% of infestation rate) but decreased in the following spring. The most important factor explaining parasite occurrence in both seasons was the nest size. Further factors, such as the presence of other parasites, the Myrmica species or the site, concurred to explain the differential survival of Ma. teleius until the final development. Irrespective of the host nest distribution, the parasite distribution changed from even in autumn to clumped in late spring. Our work showed that the survival of Ma. teleius is correlated with colony features but also with the nest spatial distribution, which therefore should be taken into consideration in conservation strategies aiming at preserving these endangered species.

The combined variation in gene expression and environmental conditions during flower development can result in phenotypic differences in shape, size, and material composition. Biomechanical responses in flower organs due to external stimuli can be mechanically measured at various levels. Here, we investigate snapdragon (Antirrhinum litigiosum) response to vibro-acoustic stimuli by an interdisciplinary model updating framework. In a climate-controlled setup, sweep signals and artificial signals representative of plant pollinator species were given as excitation input through a loudspeaker to a set of plants; vibrations of the flower organs were measured by laser Doppler vibrometry. Geometric features of the plants were identified using LiDAR combined with photogrammetry, while the density distribution in the flower organs and internal dimensions were estimated using micro-computed tomography scans. A computer model using finite element method was used to identify material properties of the flower organs by combining time domain measurements and dimensional classification. Results demonstrate density and stiffness gradient in the corolla contributing to a modal activity that is adaptive to local conditions and pollinators, but resilient against external noise. The framework outlined herein may give clues to which pollinators induce early-plant responses. [The authors acknowledge the support of the Human Frontier Science Program (HFSP) grant RGP0003/2022.]

Eusociality represents the higher degree of interaction in insects. This complex social structure is maintained through a multimodal communication system that allows colony members to be flexible in their responses, fulfilling the overall society's needs. The colony plasticity is supposedly achieved by combining multiple biochemical pathways through the neuromodulation of molecules such as biogenic amines, but the mechanisms through which these regulatory compounds act are far from being fully disentangled. Here, we review the potential function of major bioamines (dopamine, tyramine, serotine, and octopamine) on the behavioral modulation of principal groups of eusocial Hymenoptera, with a special focus on ants. Because functional roles are species- and context-dependent, identifying a direct causal relationship between a biogenic amine variation and behavioral changes is extremely challenging. We also used a quantitative and qualitative synthesis approach to summarize research trends and interests in the literature related to biogenic amines of social insects. Shedding light on the aminergic regulation of behavioral responses will pave the way for an entirely new approach to understanding the evolution of sociality in insects.

The geomagnetic field (GMF) can affect a wide range of animal behaviors in various habitats, primarily providing orientation cues for homing or migratory events. Foraging patterns, such as those implemented by Lasius niger, are excellent models to delve into the effects of GMF on orientation abilities. In this work, we assessed the role of GMF by comparing the L. niger foraging and orientation performance, brain biogenic amine (BA) contents, and the expression of genes related to the magnetosensory complex and reactive oxygen species (ROS) of workers exposed to near-null magnetic fields (NNMF, ~40 nT) and GMF (~42 µT). NNMF affected workers' orientation by increasing the time needed to find the food source and return to the nest. Moreover, under NNMF conditions, a general drop in BAs, but not melatonin, suggested that the lower foraging performance might be correlated to a decrease in locomotory and chemical perception abilities, potentially driven by dopaminergic and serotoninergic regulations, respectively. The variation in the regulation of genes related to the magnetosensory complex in NNMF shed light on the mechanism of ant GMF perception. Overall, our work provides evidence that the GMF, along with chemical and visual cues, is necessary for the L. niger orientation process.

The global loss of biodiversity is an urgent concern requiring the implementation of effective monitoring. Flying insects, such as pollinators, are vital for ecosystems, and establishing their population dynamics has become essential in conservation biology. Traditional monitoring methods are labour-intensive and show time constraints. In this work, we explore the use of bioacoustic sensors for monitoring flying insects. Data collected at four Italian farms using traditional monitoring methods, such as hand netting and pan traps, and bioacoustic sensors were compared. The results showed a positive correlation between the average number of buzzes per hour and insect abundance measured by traditional methods, primarily by pan traps. Intraday and long-term analysis performed on buzzes revealed temperature-related patterns of insect activity. Passive acoustic monitoring proved to be effective in estimating flying insect abundance, while further development of the algorithm is required to correctly identify insect taxa. Overall, innovative technologies, such as bioacoustic sensors, do not replace the expertise and data quality provided by professionals, but they offer unprecedented opportunities to ease insect monitoring to support conservation biodiversity efforts.

Many parasites interfere with the behaviour of their hosts. In social animals, such as ants, parasitic interference can cause changes on the level of the individual and also on the level of the society. The ant-parasitic fungus Rickia wasmannii influences the behaviour of Myrmica ants by expanding the host’s nestmate recognition template, thereby increasing the chance of the colony accepting infected non-nestmates. Infected ants consistently show an increase of the alkane tricosane ( n -C23) in their cuticular hydrocarbon profiles. Although experimental application of single compounds often elicits aggression towards manipulated ants, we hypothesized that the increase of n- C23 might underlie the facilitated acceptance of infected non-nestmates. To test this, we mimicked fungal infection in M. scabrinodis by applying synthetic n -C23 to fresh ant corpses and observed the reaction of infected and uninfected workers to control and manipulated corpses. Infected ants appeared to be more peaceful towards infected but not uninfected non-nestmates. Adding n -C23 to uninfected corpses resulted in reduced aggression in uninfected ants. This supports the hypothesis that n -C23 acts as a ‘pacifying’ signal. Our study indicates that parasitic interference with the nestmate discrimination of host ants might eventually change colony structure by increasing genetic heterogeneity in infected colonies.

Introduction In the vineyard, yeast communities impact the ripening and fermentation of grapes and are influenced by geographical location, climate, and soil characteristics. Despite the great advancement in our knowledge of the vineyard mycobiota, a key step of the process leading to the definition of the vineyard yeast community is still poorly understood: if geography, climate, and soil influence the mycobiota, potentially through selection, where do the yeast originate from, and how can they reach the vineyard? In this perspective, it is currently acknowledged that forests host several yeast species and that insects, particularly social wasps, can vector and maintain the yeasts known to populate the vineyard. Alas, the conveyance, fostered by insects, of yeasts from the forest to the vineyard has not been proven yet. In this study, we aimed to assess the existence of links between a potential natural source of yeasts (woods), the vectors (social wasps), and the composition of the vineyard mycobiota. Methods For this purpose, the mycobiota of wasps caught in six Italian vineyards were analyzed over 2 years through culturomics approaches. Results The results clearly indicate that the presence of wooded areas close to vineyards is associated with particular features of the mycobiota vectored by social wasps. Wasps caught in vineyards near wooded areas bear a higher number of yeast cells and higher biodiversity than insects caught in vineyards far from woods. Furthermore, insects caught in vineyards close to woods bear distinctive yeast populations, encompassing species such as Saccharomyces cerevisiae. Discussion Overall, our work provides fundamental insights into the ecology of the vineyard mycobiota and highlights the need to maintain a vineyard-woodland mosaic landscape, thus preserving the suitable habitat for yeast species relevant to wine-making.

Our work aims to assess how butterfly communities in the Italian Maritime Alps changed over the past 40 years, in parallel with altitudinal shifts occurring in plant communities. In 2019, we sampled butterflies at 7 grassland sites, between 1300–1900 m, previously investigated in 2009 and 1978, by semi-quantitative linear transects. Fine-scale temperature and precipitation data elaborated by optimal interpolation techniques were used to quantify climate changes. The changes in the vegetation cover and main habitat alterations were assessed by inspection of aerial photographs (1978–2018/1978–2006–2015). The vegetation structure showed a marked decrease of grassland habitats and an increase of woods (1978–2009). Plant physiognomy has remained stable in recent years (2009–2019) with some local exceptions due to geomorphic disturbance. We observed butterfly ‘species substitution’ indicating a general loss in the more specialised and a general gain in more tolerant elements. We did not observe any decrease in species richness, but rather a change in guild compositions, with (i) an overall increased abundance in some widespread and common lowland species and (ii) the disappearance (or strong decrease) of some alpine (high elevation) species, so that ‘resilience’ could be just delusive. Changes in butterfly community composition were consistent with predicted impacts of local warming.

Climate change is causing shifts in the distribution of many species and populations inhabiting mountain tops are particularly vulnerable to these threats because they are constrained in altitudinal shifts. Apennines are a relatively narrow and low mountain chain located in Southern Europe, which hosts many isolated populations of mountain species. The butterfly Erebia pandrose was recorded for the last time in the Apennines in 1977, on the top of a single massif (Monti della Laga). We confirmed the presence of a small, isolated population of E. pandrose in the Apennines, at a distance of more than 400 km to any other known populations. Then, we examined the cytochrome c oxidase subunit 1 mitochondrial DNA marker of this species across the Palaearctic area and estimated the potential decline over the Alps and the Apennines due to future climatic changes. The Apennine population represents an endemic lineage characterised by eight mutations over the 658 bp analysed (1.2%). In the Alps and Apennines, this species has shifted uphill more than 3 m per year since the end of the 19th century and more than 22 m per year since 1995. Species distribution models suggested that these mountain populations will experience a generalised loss of climatic suitability, which, according to our projections, could lead to the extinction of the Apennine population in a few decades. Erebia pandrose has the potential to become a flagship species for advertising the risk of losing unique fractions of genetic diversity for mountain species.

Uncovering variation in social insect communication Alessandro CINI*, Luca Pietro CASACCI*, and Volker NEHRING* Centre for Biodiversity & Environment Research, University College London, Gower Street, London, WC1E 6BT, UK, Dipartimento di Biologia, Università degli Studi di Firenze, Via Madonna del Piano, Sesto Fiorentino, Firenze, 50019, Italy, Department of Life Sciences and Systems Biology, University of Turin, Via Accademia Albertina 13, Turin, 10123, Italy, and Department of Evolutionary Biology and Ecology, Institute of Biology I (Zoology), University of Freiburg, Hauptstraße 1, Freiburg (Brsg.), 79104, Germany