Peer Community Journal

In search of recurrent patterns of postzygotic hybrid incompatibility, we investigated the Holarctic 'Old World Swallowtail' (Papilio machaon Linnaeus) butterfly complex, whose members can easily be crossed in the laboratory. How many species this model system comprises remains unclear, as taxa with highly distinctive larvae but uncertain status come into contact with authentic P. machaon subspecies in Southern parts of the Palearctic region. By determining mitochondrial and ITS2 haplotypes within and away from contact zones, we found that these neighboring populations do exchange genes, as expected from F1 hybrids being generally fertile in our laboratory crosses. Nevertheless, recurrent instances of dysregulation of diapause were uncovered in hybrid progenies. In keeping with Haldane's Rule, pupae of the heterogametic (female) sex were either unable to enter diapause or, in reciprocal crosses, unable to resume development after having initiated diapause, whereas F1 males experienced normal, photoperiod-regulated diapause, but passed on abnormal diapause regulation to part of their female offspring when backcrossed. Comparing male and female pupal weights in hybrid progenies provides estimates of parental incompatibility that allow to rank taxa and predict quantitatively the outcome of additional crosses, as expected if the same regulatory system were involved. A survey of the entomological literature confirms that diapausing pupae that cannot resume development ('perpetual nymphs') are a recurrent feature of interspecific lepidopteran crosses. Moreover, of the two parent species of a perpetual nymph, the paternal one generally has fewer broods per year. These observations are discussed in the light of models of the speciation process.

The pinewood nematode is a dangerous organism for the health of Pine forests and has already demonstrated its impact in Portugal and Spain. This organism was recently detected (november 2025) in France. It can spread over long distances (e.g., through wood transport) or short distances via its insect vector flights (about fifteen km), Monochamus galloprovincialis. The spatiotemporal distribution of the population of this insect vector is poorly understood in France. In this study, we propose to estimate the Monochamus population using official but heterogeneous in space and time trapping data. This spatiotemporal modeling is based on two Bayesian approaches (an INLA-based generalized additive model, and a mecanistic-statistical approach) and integrates environmental covariates as well as laboratory-derived experiments data about the insect vector. The results provide estimates and predictions of the spatiotemporal distribution of Monochamus galloprovincialis in France. This distribution varies according to environmental conditions and biological characteristics of the insect; the population dynamics thus can thus be estimated at all points in space and time. They will significantly improve the pinewood nematode surveillance plan to better monitor free zones and buffer zones around the outbreak.

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.

Demographic models are crucial for uncovering the mechanisms underlying changing populations trajectories and structure and to identify the drivers of such changes. Common pochard populations of North east/North west Europe have experienced a sharp decline accompanied by an increase in male proportions among adults since the mid-1990. We used a two-sex, two-stage deterministic matrix population model, to perform a prospective perturbation analysis and to explore, through simulations, some plausible causes underlying the observed decline and change in sex structure. We show that Common pochard populations are more sensitive to changing survival than to changes in productivitys components (clutch size, nest survival...). However, due to an environmental variance much higher than that of survival, components of productivity, especially nest survival, would be the main drivers of Common pochard populations growth rate, a finding supported by empirical data. More importantly, we show that although sex-specific changes in survival at any stage of the life cycle are potent drivers of both population growth rate and changing sex ratio, there is no need to resort to them for explaining the increasing proportions of males such as observed in Common pochard. Because adult males display higher survival than adult females (0.74 against 0.64 on average), any factor affecting recruitment (nest or first year survival) increases the weight of adults into the populations and hence the proportion of males. Thus, in species displaying sex-biased mortality, such as many ducks, decreasing recruitment can underly declining population size and changes in sex structure at the same time, emphasising the importance of accounting for males in monitoring schemes and demographic models.

The multivoltine non-native box tree moth, Cydalima perspectalis (Lepidoptera: Crambidae), was accidentally introduced in several continents and exhibited a very rapid expansion in its invaded ranges, colonising around 40 countries in less than twenty years. Initially observed in urban areas, it quickly spread to forest stands, causing significant damage to boxwood trees. If the role of the ornamental plant trade in its fast invasion has been investigated, the insects flight capabilities has thus far been overlooked, limiting estimations of its natural dispersal. In this context, we assessed the flight performance of the adults and investigated potential effects of sex, age and generation using computer-monitored flight mills. Under these controled conditions, we estimated the distance flown per night and over the adults lifespan in both sexes for each generation. The adults were able to fly on average 18 km within their lifespan, even though distances flown were highly variable, including several females capable of performing long-distance flights (up to 150 km). The distances covered were partly correlated with the age and body mass of the adults. Mated females flew longer distances than virgin ones, but long dispersal seemed to limit their fecundity. Finally, the overwintering generation presented the highest flight capabilities with individuals able to cover 22 km on average while the late summer generation covered only 10 km. The box tree moth showed good dispersal abilities that likely played a significant role in its rapid local expansion, while human-mediated dispersal favoured its long-distance dispersal.

Nature-Based Solutions are increasingly promoted to address current urban challenges. While their potential effects on vector-borne disease risks have been documented, data on Aedes albopictus, a known arbovirus vector, remain limited in France. A previous study showed that urban vegetation moderately increases the abundance of adult mosquitoes of this species, but the monitoring period lasted only six months. Using ovitraps, we monitored Ae. albopictus egg density dynamics over multiple years (2022 to 2024) and analysed its environmental predictors in various urban environments. We included lagged meteorological variables, land cover metrics, and the cumulated egg densities recorded in the previous weeks as environmental predictors. Both parametric (GLMM) and non-parametric (Random Forest) models were fitted to weekly egg counts per trap. Our findings highlight that (i) egg density dynamics were related to how vegetation classes structured the landscape, (ii) growing degree days and cumulated number of eggs recorded in specific lagged time windows were the main contributors to egg density, and (iii) the non-parametric and parametric models performed similarly in terms of prediction accuracy.

In nature, the most common drivers of lethal aggression are predation and territorial defense. In northeastern Poland, the yellow-necked mouse (Apodemus flavicollis) coexists with several rodent species, including the bank vole (Clethrionomys glareolus). Compared to voles, A. flavicollis is larger, physically stronger, more aggressive, and dominant in the social ecosystem. However, no visually documented instance of a lethal attack by this species has been reported up to date. Here, we present the first recorded case of a fatal attack by a yellow-necked mouse following an encounter with a bank vole. A near-lethal attack is also reported. Importantly, these attacks were not predatory, as no consumption occurred. The attacks appeared instead to be related to interspecies competition, i.e., to competitive interactions between two species that live in the same habitat and use the same type of resources. Notably, while the aggressiveness of yellow-necked mice towards bank voles was known, it was unknown that it could take such extreme forms. Since, in rodents, most competition-related agonistic interactions are aimed at distancing the competitor, the physical destruction of the competitor appears as a surprisingly extreme way of addressing the game of interspecies competition through definitive removal of the opponent. Our observations highlight the need for further research on interspecific aggression among small mammals. They also emphasize the importance of field-based methods, such as camera trapping and continuous video monitoring, which allow for direct observation of animal behavior in natural settings and can reveal rare or previously overlooked interactions.

We describe a chromosome-level, haplotype-resolved genome assembly from a male European moose (Alces alces alces). The assembly comprises two pseudo-haplotypes of 3,148 Mb and 3,112 Mb, with sex chromosomes in haplotype one, and 33 autosomes in each haplotype (68 in total). Assembly completeness is high (BUSCO 98.3% and 95.7%), with 21,496 and 20,498 annotated protein-coding genes for haplotypes one and two, respectively. This genome assembly is the most complete so far generated for European moose.

In trypanosmatids genes, transcribed by RNA polymerase II do not have canonical promoters and are organized into directional gene clusters that mature into monocistronic transcripts by a co-transcriptional process known as trans-splicing. Even though gene expression is regulated mainly post-transcriptionally, it is currently understood that chromatin and epigenetics are also involved in this regulation. In eukaryotes, specific signals are normally required for the occurrence of an appropriate transcription initiation. Among them, trimethylation of histone H3 in lysine 4 is the most conserved signal normally detected at transcription start sites of actively transcribed genes. Unlike many model organisms, trypanosomes do not have defined promoters. Instead, transcription initiates in a bidirectional manner from dispersed regions coincident with divergent strand switch regions located between directional gene clusters (DGCs). In T. cruzi, H3K4me3 was observed at the origins of transcription coincident with divergent strand switch regions (dSSRs) in epimastigotes, but it has not been mapped throughout the whole genome at base-pair resolution or in other life stages so far. Here, we set up the CUT&RUN technique for T. cruzi epimastigotes and trypomastigotes. Consistent with a predominant post-transcriptional regulation along the life cycle, we did not find significant differences between life stages. We corroborated that H3K4me3 is enriched at dSSR adjacent to actively expressed DGCs. Moreover, we noticed that this histone mark exhibits different patterns that correlate with the genomic span of the transcription initiation regions and with transcriptional activity. Furthermore, we unveiled that the most actively transcribed DGCs are associated with shorter dSSRs and are located within the core compartment of the genome displaying a more accessible chromatin.

BackgroundLyme borreliosis is a common tick-borne disease in Europe caused by spirochetes of the Borrelia burgdorferi sensu lato complex, including Borrelia afzelii, which is maintained in nature through interactions with rodent reservoir hosts. These spirochetes have evolved several surface proteins to manipulate rodent host immunity, some of which remain polymorphic in Borrelia populations. Among these proteins, OspE, which binds the host complement-regulating factor CFH to evade destruction by complement, is one of the most variable. Yet, what evolutionary forces maintain this polymorphism is not well understood. Motivated by a recent discovery of CFH polymorphism in the bank vole (Clethrionomys glareolus), the main reservoir host of B. afzelii, we hypothesized that the polymorphism is maintained by host-parasite coevolution involving specific associations between host and parasite genetic variants. MethodsWe analyzed associations between bank vole CFH alleles and B. afzelii OspE variants across three datasets sampled in Poland. Selection acting on OspE was evaluated using omegaMap. Host-pathogen genotype associations were tested using partial redundancy analysis (RDA), and co-structure was assessed using co-correspondence analysis (CoCA). ResultsWe found that OspE evolves under positive selection, however, we found no evidence for an association between OspE and host CFH variants at the individual level based on RDA or at the population level based on CoCA. ConclusionsDespite evidence of positive selection acting on OspE, we found no support for specific genetic matching between B. afzelii and its bank vole host at the CFH-OspE interface. These results suggest that the evolution of CFH and OspE may be shaped by broader selective pressures, potentially including interactions with multiple host species.

BackgroundWest Nile virus (WNV) is a vector-borne zoonotic pathogen maintained in an enzootic cycle between birds and mosquitoes which is considered a significant public health concern in Europe, particularly in relation to its recent increase in reported human cases and range expansion. While a comprehensive understanding of the viruss epidemiological dynamics is essential to inform effective prevention and control strategies, to date significant knowledge gaps remain in quantifying interspecific differences within the complex avian communities involved in WNV circulation. Globally, WNV-infection has indeed been documented across more than 300 bird species, however, whether and how inter-specific differences in avian hosts traits affect the spread of WNV is still largely unknown. A substantial body of research has investigated how epidemiological traits, such as the duration of infection and competence, influence WNV dynamics. However, much less is known about the role of avian demography. Methodology/Principal findingsWe therefore investigated through mathematical modelling the role of avian demographic traits in shaping patterns of mosquito WNV infection dynamics in northern Italy (Lombardy Region, 2016-2018). We focused on the effects of annual offspring production, timing and synchrony of breeding which ultimately affect seasonal abundance of competent avian hosts. We highlighted that timing of breeding has the greatest effect on the number of infected mosquitoes, while annual offspring production influences the timing of the infection peak. Our simulations provide evidence that non-corvid species can have a key impact on WNV transmission. Conclusion/SignificanceThese results can support future research by providing priority bird species to direct further studies and by suggesting that the acknowledgment of spatio-temporal variation in the abundance of competent avian hosts plays a key role in the development of effective surveillance strategies and mosquito control actions. Author summaryWest Nile virus (WNV) is endemic in Italy and represents a significant public health threat in Europe, with increasing cases of severe neuroinvasive disease in humans in recent years. Surveillance data reveal marked spatial and temporal variability in infection dynamics, suggesting that key drivers of WNV transmission remain poorly understood. The contribution of different bird species (over 300 are implicated in the WNV cycle) is often overlooked despite evidence that species-specific traits are critical determinants of WNV infection dynamics. Few studies have examined birds demographic traits, despite their well-established importance in shaping infection dynamics across diseases. Given the challenges in collecting detailed wildlife data, we employed mechanistic models to explore transmission scenarios and test whether avian demographic traits influence bird species roles in WNV transmission and maintenance in Lombardy. Our findings demonstrate that brood size, hatching synchrony, and hatching time significantly affect estimated WNV prevalence in mosquitoes.

Life history strategies such as rapid growth and high population turnover rates observed in vertebrates have been thought to have emerged relatively late in evolution. However, very little direct evidence exists at the species level for early vertebrates. In this study, a large fossil collection of over 450 specimens of Protaspis spp, heterostracan agnathans from the Cottonwood Canyon Formation at Beartooth Butte, Wyoming, from the Early Devonian, was analyzed. Morphological observations, analysis of bone plate completeness, and length-frequency analyses using ELEFAN--commonly used in recent fish studies--were applied to reconstruct growth rates, cohort structure, and ontogenetic processes. Protaspis specimens exhibited a continuous growth series from juvenile to adult stages, and a clear cohort structure was identified from the length-frequency distributions. The ELEFAN analysis suggested a life-history characterized by rapid growth and a short life span, and these features remained consistent in subset analyses restricted by species or locality, confirming the robustness of the estimates. Furthermore, the integration of the dermal bone plates progressed during the late stages of ontogeny, revealing that the rapid growth during the juvenile stage preceded the completion of this defensive structure. Comparisons of their growth parameters with those of extant fishes show that Protaspis does not align with slow-growing, long-lived "living fossil" taxa, but instead clusters with small-bodied, fast-growing species. These findings suggest that life-history strategies involving rapid growth and high population turnover were already established in early jawless vertebrates, much earlier than previously assumed.

Culex pipiens is a major vector of West Nile Virus (WNV) in Europe and has a complex evolutionary history that has been linked to the probability of WNV spillover to humans. Here, we present a population genomic analysis of Cx. pipiens from a WNV hotspot in southwestern Spain. Whole-genome sequencing of 217 individuals from 24 localities revealed that population structure is mainly shaped by the coexistence of pipiens and molestus ecotypes. Despite clustering, genome-wide divergence between ecotypes was low, consistent with shared ancestral variation. Furthermore, Wolbachia infection was heterogeneous across the study area, where some Culex pipiens pipiens remain uninfected. We also identified three new polymorphic chromosomal inversions on chromosomes 1 and 3 that segregate independently. Although inversions did not underlie ecotypic differentiation, they were enriched for genes involved in olfaction and insecticide resistance pathways, suggesting potential adaptive and epidemiological relevance. Distance-based redundancy analyses showed that ecotype identity explained the largest fraction of genetic variance, with additional contributions from Wolbachia infection, habitat type (urban versus rural) and geographic distance. These results reveal that partial ecotypic differentiation, symbiont infection, and habitat interact to shape population structure in Cx. pipiens, with implications for vector ecology and disease transmission.

In this study, I implemented an agent-based model aimed at exploring the competition between plastic and non-plastic genotypes in a digital environment with periodic fluctuations in food resources, using the dimorphic nematode Pristionchus pacificus as a proxy for mixed-strategy systems showing a combination of stochastic and conditional phenotype production. Emerging behaviours generated in response to variation in three main variables, that is, i) intrinsic cost of plasticity, ii) timescale of environmental fluctuation, and iii) degree of plasticity, were monitored in terms of frequency and time to fixation of two alleles of the developmental switch gene eud-1, one enabling mouth-form dimorphism and predation, the other leading to the constitutive expression of a single, bacterivorous morph. Interestingly, while intermediate-to-long periods of environmental stability (in terms of generations) and a higher level of plasticity might favour the evolution of plastic strategies in a "cost-free" condition, the introduction and increase of inherent costs of plasticity could make pure bet-hedging more advantageous, induce a sequential collapse in the frequency of fixation of plastic strains and time of coexistence between strains, and make the invasion by non-plastic mutants more likely until a plateau is reached. In addition, asymmetries in fitness between the two morphs might be an almost necessary condition to enable the invasion of a non-plastic population by plastic genotypes. Collectively, while confirming some previous theoretical findings, these outcomes could uncover the sensitivity of a mixed-strategy system to even small changes in key variables, suggesting the existence of phase transitions and critical evolutionary constraints.

Veterinary ectoparasiticides widely used on companion animals often contain synthetic insecticides whose agricultural applications have been restricted in the European Union because of environmental concerns. These neurotoxic compounds can persist on animal fur and enter surrounding environments, potentially exposing non-target organisms. The Great Tit (Parus major), a common passerine in both urban and forest habitats, frequently incorporates animal fur in nest linings, thereby creating a potential exposure route for breeding adults and nestlings. We analysed fur-containing nest material collected from 63 Great Tit nests in artificial nest boxes at an urban site and a nearby protected forest in Hungary during the 2025 breeding season, sampling at mid-nestling stage and also after fledging. Using HPLC-MS/MS and GC-MS, we detected several veterinary ectoparasiticides in nest materials, including fipronil, fipronil sulfone, imidacloprid, and permethrin. Acetamiprid was found only in urban nests, indicating additional, non-veterinary environmental sources. Multiple insecticides were present in nest material, with higher contamination levels and greater compound diversity in urban compared to forest nests. Residues were present at both sampling times but declined over the course of the breeding cycle. Although contamination was not associated with the measured reproductive parameters of Great Tits, our findings show that veterinary ectoparasiticides can contaminate wild bird nests, including those in protected forest ecosystems. This highlights a previously under-recognised pathway linking companion animal treatments to wildlife exposure and underscores the need to assess the ecological risks and trade-offs associated with widespread veterinary insecticide use. HighlightsO_LIVeterinary ectoparasiticides were detected in urban and forest Great Tit nests C_LIO_LIUrban nests contained higher contamination levels and greater compound diversity C_LIO_LIAcetamiprid occurred only in urban nests, indicating additional environmental inputs C_LIO_LIProtected forests also exposed to fipronil, fipronil sulfone and permethrin C_LIO_LIBird nests reveal an overlooked pathway linking pet treatments to wildlife exposure C_LI

The marbled teal (Marmaronetta angustirostris) is a widely distributed but declining waterfowl species, classified as Near Threatened globally and Critically Endangered in Spain. Despite ongoing conservation actions, including ex situ management and population reinforcement programmes, the genomic consequences of long-term captivity, inbreeding, and patterns of functional genetic variation remain unknown due to the absence of a species-specific reference genome. Here, we present the first chromosome-level genome assembly for this species. The genome was generated using PacBio HiFi long reads and Omni-C data, yielding a 1.15Gb assembly with a scaffold N50 of 76.95Mb. A total of 97.16% of the assembly was anchored into 36 chromosome-scale scaffolds, including the Z and W sex chromosomes. BUSCO analysis recovered 99.2% of conserved avian genes. Gene prediction was performed using both ab initio and homology-based strategies, resulting in 16,048 protein-coding genes. This resource provides a foundation for genomewide analyses of inbreeding, demographic history, and adaptive variation, and will support evidencebased in situ and ex situ conservation strategies for this threatened species.

Synchronising birth timing with the adequate environmental conditions as well as with congeners can affect juvenile survival and at a later stage, recruitment. In the case of endangered species, understanding the factors driving birth phenology is therefore critical to implement effective conservation and reintroduction policies. Currently, 75% of the Perissodactyla species (odd-toed ungulates) are threatened and some even already had to be reintroduced in their natural habitat. Using a comparative analysis framework, we investigated the effect of nine environmental, life history and predation factors on the synchrony of births in 27 populations of wild Perissodactyla across Africa and Asia. We confirmed the positive effect of environmental seasonality and latitude, as well as the negative effect of environmental productivity on birth synchrony, but we found no significant effect of environmental unpredictability. Life history traits had limited effects on birth synchrony in this order: the intensity of daily reproductive effort and pace of life were non-significant, and migratory behaviour had an unexpected positive association with birth synchrony, suggesting that the link between migration and reproduction might be more complex than the relief of environmental constraints initially expected. We found a positive effect of group size on birth synchrony, in line with the swamping hypothesis to reduce predation risk on neonates, but we found no strong support for a positive effect of predation exposure, measured as a qualitative index combining species-specific sensitivity to predation and site-specific predator abundance. Overall, our findings suggest that individuals adjust reproductive cycles in response to local ecological and social conditions, suggesting that conservation efforts such as reintroductions could benefit from taking into account the extent of the differences between the site of origin and the reintroduction site.

Mark-recapture analyses on the delineation of natural populations between areas often assume random sampling, with a between/within (B/W) area resighting ratio that declines towards zero as the population components of two areas become more-and-more isolated from one another, with fewer-and-fewer individuals mixing between areas. I use an individual based population model split in two areas to simulate this result, analysing also for the potential effects of the space-time fidelity of the mark-recapture sampling in the areas. I find that small B/W resighting ratios--that traditionally is taken as evidence of population isolation--can easily be observed within a completely mixing population if a random sampling scheme is restricted in space and/or time. Random sampling within restricted areas and time windows is not sufficient to estimate mixing rates and population isolation between areas, unless the resighting rates are analysed by a method that accounts both for the space-time fidelity of the scientific sampling scheme and the space-time fidelity of the distributional behaviour of the individuals in the population.

MotivationHigh-quality biodiversity data with temporal replicates, produced using standardized fieldwork protocols, are rare yet essential for studying long-term biodiversity dynamics. Most available large-scale temporal data only date back one or two decades and/or originate from spatially discrete local observations. Here, we release spatially contiguous, systematically collected, and gridded occurrence data for breeding birds in Czechia, covering the periods 1973--1977, 1985--1989, 2001--2003, and 2014--2017. This database represents the monitoring of ca. 41% of European bird species over 40 years, and it is one of the longest-running nationwide bird-monitoring efforts in the world. We also complement the original data with geospatial metrics to characterize the sampling polygons and provide proxies of sampling effort. By making this dataset openly accessible, we aim to strengthen biodiversity change studies, citizen science, and ornithological research with long-term, highly curated records, backed by well-documented methods, and ready for integration with other datasets. Main Types of Variables ContainedA total of 286302 breeding bird detections/non-detections per-grid-cell from 247 species (ca. 41% of the 596 species breeding in Europe). The fourth atlas also contains 9,471 timed species lists totaling 276076 additional records collected with standardized effort and partially random spatial sampling on smaller squares dividing the original grid cells. Spatial Location and GrainCzechia (total area of 78,871 km2) covered by a grid of 887 grid cells of 10 by 10 km for the period 1973--77, and 678 cells of 6 minutes latitude and 10 minutes longitude ([~]11.2 x 12 kilometers) from 1985 onwards. The timed species lists were collected across 4,851 of 9,844 small squares ([~]2.8 x 3 km) that subdivide each original grid-cell into 16 smaller polygons. Time Period and GrainThe sampling years were 1973--1977 (5 breeding seasons), 1985--1989 (5 breeding seasons), 2001--2003 (3 breeding seasons), and 2014--2017 (4 breeding seasons). Major Taxa and Level of MeasurementBirds (Aves). The breeding evidence per species and grid cell was classified following the European Breeding Birds Atlas 2. We provide species-level records matched to the HBW/BirdLife version 9 (2024). FormatThe dataset is available for download from Zenodo and is provided as CSV files with fields standardized to Darwin Core, and a GeoPackage file containing all of the spatial grids used. The data are organized into separate files for records and sampling events, corresponding to each atlas. All data are licensed under CC-BY 4.0.

The migratory endoparasitic pinewood nematode (PWN), Bursaphelenchus xylophilus, is the causal agent of pine wilt disease, causing significant economic and ecological losses in conifer forest ecosystems in Europe and Asia. Understanding the molecular mechanisms regulating PWN parasitism-related genes may lead to new sustainable solutions for control. Based on previous PWN transcriptomic datasets from the pre-parasitic and parasitic stages and from the pharyngeal gland cells (GC), an in silico analysis was performed to identify transcription factors (TF) highly expressed in the GC. Seven candidates TF genes were selected, and their spatial expression validated by in situ hybridisation. From those, two GC-expressed TFs, BXY_079 and BXY_022, each encoding zinc finger domains, were successfully knocked down by RNA interference. Transcriptomic data from silenced BXY_079 and BXY_022 TFs, analysed with existing life cycle specific transcriptomic data, showed that both TFs control genes expressed at similar times, by repressing male-related genes while activating genes expressed during the J3 and D3 stages, yet each represents the extreme of the others minor function. In addition to these common roles, BXY_079 also activates parasitism-related genes in the J2 stage. These BXY_079-activated parasitism-related genes predominantly encode proteins with lytic functions, including secreted peptidases and glycoside hydrolases. Consistent with their proposed role in parasitism, these genes are highly expressed during the parasitic juvenile stages and are likely involved in nematode feeding, tissue penetration, and migration within the host. In contrast, BXY_022 also represses the expression of several genes related to the reproduction system, such as major sperm proteins and cytosolic motility proteins, particularly in the adult male stage. Taken together, both dual-functional TFs work together, non-redundantly, to regulate gene expression across the life cycle, while each is additionally specialised to regulate diverse and distinct gene sets: ranging from genes implicated in lytic parasitic functions to sexual dimorphism.