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Aim: Quantifying the relative contribution of environmental filtering versus limiting similarity in shaping communities is challenging because these processes often act simultaneously and their effect is scale‐dependent. Focusing on caves, island‐like natural laboratories with limited environmental variability and species diversity, we tested: (i) the relative contribution of environmental filtering and limiting similarity in determining community assembly in caves; (ii) how the relative contribution of these driving forces changes along environmental gradients. Location: Europe. Time period: Present. Major taxa studied: Subterranean spiders. Methods: We used data on distribution and traits for European cave spiders (n = 475 communities). We estimated the trait space of each community using probabilistic hypervolumes, and obtained estimations of functional richness independent of the species richness of each community via null modelling. We model functional diversity change along environmental gradients using generalized dissimilarity modelling. Results: Sixty‐three percent of subterranean spider communities exhibited a prevalence of trait underdispersion. However, most communities displayed trait dispersion that did not depart significantly from random, suggesting that environmental filtering and limiting similarity were both exerting equally weak or strong, yet opposing influences. Overdispersed communities were primarily concentrated in southern latitudes, particularly in the Dinaric karst, where there is greater subterranean habitat availability. Pairwise comparisons of functional richness across caves revealed these effects to be strongly scale‐dependent, largely varying across gradients of cave development, elevation, precipitation, entrance size and annual temperature range. Conversely, geographical distance weakly affected trait composition, suggesting convergence in traits among communities that are far apart. Main conclusions: Even systems with stringent environmental conditions maintain the potential for trait differentiation, especially in areas of greater habitat availability. Yet, the relative influence of environmental filtering and limiting similarity change with scale, along clear environmental gradients. The interplay of these processes may explain the assembly of species‐poor subterranean communities displaying high functional specialization. [ABSTRACT FROM AUTHOR]

Aim: To assess the relative relevance of dispersal limitation and species sorting as drivers of spatial turnover between spider faunas of European territories. Location: Continental Europe. Time period: Present. Major taxa studied: Spiders (Order Araneae). Methods: We analysed how distance‐decay patterns differ between northern and southern Europe (broadly, territories covered vs. not covered by ice sheets during the last glacial maximum, respectively) in 15 spider families, using standardized distances to allow a direct comparison between parameters (i.e. slope and intercept) of climatic and spatial distance‐decay models. Thus, we assessed North–South differences in parameters of spatial and, independently, climatic distance‐decay models, and whether those differences are explained by family‐specific traits related to dispersal ability. Results: Climatic and spatial distance‐decay patterns are very similar in northern Europe, where climatic and spatial distances are highly correlated. In contrast, slopes are steeper in spatial than in climatic distance‐decay curves in southern Europe, where climatic and spatial distances are decoupled. Moreover, family traits related to dispersal ability explained the North–South difference in spatial distance‐decay slopes, as well as the amount of nestedness‐resultant dissimilarity between southern and northern spider faunas. Main conclusions: Our results suggest that differences in beta diversity patterns between northern and southern Europe reflect the strength of dispersal limitation in spiders, which varies across families and leads to different degrees of disequilibrium with current climatic conditions depending on the taxon. Moreover, in the South of Europe, where spatial and climatic distances are uncorrelated, spatial distance‐decay models are steeper and have larger explanatory power than climatic distance‐decay models, which suggests that dispersal limitation is the main factor shaping current beta diversity patterns of European spiders at the continental scale. [ABSTRACT FROM AUTHOR]

Modern agricultural pest management systems rely on naturally occurring generalist predators to promote pest suppression. Still, little research has been done to assess their overall effectiveness, especially over the winter period when their potential is high. In this study, we focused on three genera of winter-active spiders Clubiona, Philodromus, and Anyphaena, common predators on pear trees in Central Europe during winter and early spring. We investigated their predation activity, natural diet, and prey preference using molecular gut content and abundance data obtained from cardboard bands, which served as natural shelters. We compared these characteristics between two distinct biocontrol-promoting managements—integrated pest management (IPM) and organic management (ORG). We found the proportion of prey-positive spider individuals during the winter period to be lower compared to the spring period with Anyphaena having by far the highest proportion. The prey composition during winter was more diverse in ORG orchards, but in both managements, it was inclined toward pests, mostly pear psyllids. Conversely, in early spring, despite psyllids still being a part of the diet, spiders in IPM orchards preyed more frequently on neutral prey (mostly dipterans), while the spiders from organic orchards preyed mostly on pests (lepidopterans). Although more data are needed to assess trophic interactions and the overall efficiency of these winter-active predators in complex arthropod food webs present in pear orchards, the results obtained from this research provide the first evidence of higher pest predation during a period of agricultural quiescence. [ABSTRACT FROM AUTHOR]

There is a secret pleasure in naming new species. Besides traditional etymologies recalling the sampling locality, habitat or morphology of the species, names may be tributes to some meaningful person, pop culture references and even exercises of enigmatography. Using a dataset of 48 464 spider etymologies, we tested the hypothesis that species names given by taxonomists are deeply influenced by their cultural background. Specifically, we asked whether naming practices change through space or have changed through time. In absolute terms, etymologies referring to morphology were the most frequently used. In relative terms, references to morphology peaked in 1850–1900 and then began to decline, with a parallel increase in etymologies dedicated to people and geography. We also observed a dramatic increase in etymologies referring to pop culture and other cultural aspects in 2000–2020, especially in Europe and the Americas. While such fashionable names often carry no biological information regarding the species itself, they help give visibility to taxonomy, a discipline currently facing a profound crisis in academia. Taxonomy is among the most unchanged disciplines across the last centuries in terms of tools, rules and writing style. Yet, our analysis suggests that taxonomists remain deeply influenced by their living time and space. [ABSTRACT FROM AUTHOR]

With climate change altering ecosystems worldwide, forest management in Europe is increasingly relying on more adaptable non-native tree species, such as Douglas fir (Pseudotsuga menziesii). However, the ecological consequences of the increased utilization of Douglas fir on arthropod diversity and ecosystem functioning are not fully known. Here we assessed how non-native Douglas fir as well as large- and small-scale differences in the environmental context, affect epigeal spider abundance, biomass, taxonomic and functional diversity, and community structure in Central European forests. Our study sites were divided into two regions with large differences in environmental conditions, with seven replicates of five stand types, including monocultures of native European beech (Fagus sylvatica), non-native Douglas fir and native Norway spruce (Picea abies), as well as two-species mixtures of European beech and each of the conifers. Contrary to our expectations, Douglas fir promoted small-scale spider diversity, and abundance and biomass (activity density). On the other hand, it decreased spider functional divergence and altered spider community structure. Microhabitat characteristics had opposing effects on spider diversity and activity density, with more open stands harboring a more diverse but less abundant spider community. Overall, our findings suggest that increasing Douglas fir utilization at the expense of Norway spruce does not necessarily decrease the diversity of epigeal arthropods and may even promote local spider diversity and activity density. However, care needs to be taken in terms of biodiversity conservation because typical forest spider species and their functional divergence were more strongly associated with native beech than with coniferous stands. [ABSTRACT FROM AUTHOR]

Simple Summary: At present, the only place in Europe where the full development cycle of forests takes place on a large scale is the Białowieża Forest, because in most other forests dead or dying trees are eliminated, so the terminal (decay) phase does not occur there. Studies of animal assemblages inhabiting different forest phases are scarce as well as studies of spiders inhabiting tree trunks and branches. In this study, we compare spider assemblages inhabiting the tree trunks and branches in the optimal, terminal and regeneration phases of a primeval oak–lime–hornbeam stand in terms of their abundance, species diversity and species richness. We did not find differences in the total spider species richness between the analysed phases. However, we found that species diversity of both foliage-dwelling and trunk-dwelling spider assemblages was higher in the terminal phase compared to the other phases, which may indicate that this phase offers the most diverse niches for spiders as a result of the significant disturbance in the forest stand structure. Our research contributes to the understanding of the functioning of natural ecosystems, which can be useful for responsible forest management. The study was conducted in the Białowieża Forest, which is the only place in Europe where the full development cycle of forests takes place on a large scale. The objective of this study was to compare spider assemblages inhabiting tree trunks and tree branches in the optimal, terminal and regeneration phases of a primeval oak–lime–hornbeam stand, in terms of their abundance, species diversity and species richness. Spiders of tree branches were sampled using a sweep net into which branches were shaken, while spiders inhabiting tree trunks were collected using traps made of corrugated cardboard placed around the trunks. The three analysed phases did not differ in terms of total species richness. We found that the species diversity of both foliage-dwelling and trunk-dwelling spider assemblages was higher in the terminal phase compared to other phases, which may indicate that the former phase offered the most diverse niches for spiders as a result of the significant disturbance in the stand structure. In addition, we found fewer spider individuals and species in individual samples collected on tree branches from a plot in the regeneration phase compared to the other phases, which may be a consequence of the structure of the stand in this phase (low canopy cover, lush herbaceous vegetation). [ABSTRACT FROM AUTHOR]

Aim: The continuous spread of invasive species is attributed to demographic processes and high dispersal rates. Both can change and evolve during range expansion, eventually accelerating spread dynamics. Here, we document such an accelerated spread for one of the most invasive spiders in Europe, the dwarf spider Mermessus trilobatus, and test whether dispersal, reproduction or competitive ability is at the source of this pattern. Location: Europe. Time period: 1981–2021. Major taxon studied: Mermessus trilobatus (Arachnida: Araneae: Linyphiidae). Methods: First, we collected records from 21 countries across Europe to document the speed of progression of the invasion front over the last 40 years. Second, we collected live individuals from populations in the longest and more recently invaded areas and compared the dispersal propensity of offspring raised under standardized conditions. Third, we compared the reproduction and competitive ability of females derived from the populations of long‐invaded areas against areas with more recent establishment. Results: The progression of the invaded range increased from about 150 km in the 1980s to some 400 km between 2010 and 2020. Dispersal‐related behaviour was nearly twice as frequent in offspring from invasion front populations compared to the core area. By contrast, we found no differences in reproduction or competitive ability among the studied populations. Further, neither joint inheritance nor trade‐offs of dispersal, reproduction or competitive ability were identified. Main conclusion: As high dispersal is recessively inherited in M. trilobatus, our results suggest that the accelerated invasion is due to the accumulation of dispersive but not more reproductive or competitive genotypes in newly colonized areas. Given the high climatic amplitude of the species in North America, we expect it to spread over the remaining parts of Europe and large parts of Asia in the coming decades. Accelerated range expansion through the evolution of dispersal behaviour could play a role in numerous arthropod invasions worldwide. [ABSTRACT FROM AUTHOR]

The spatial distribution of parasitoids is closely linked to the distribution and ecological requirements of their hosts. Several studies have documented changes in the fauna composition of parasitoids in response to elevation, but data on parasitoids associated with spiders are missing. The koinobiont ichneumonid wasp Zatypota anomala is strictly specialised on spiders of the genus Dictyna (Dictynidae) in Europe. We examined the distribution of spiders of the family Dictynidae in forest ecotones in central Europe across a broad elevation gradient (110-1466 m a.s.l.). We checked the spiders for parasitism by Z. anomala. It was most abundant at the mid-elevations (median 712 m a.s.l., range 179-870 m a.s.l.). We identified four dictynid spider species as Z. anomala hosts. These were Dictyna arundinacea, Dictyna uncinata, Nigma flavescens, and Nigma walckenaeri. All four species and the genus Nigma were recorded as hosts for the first time. The parasitoids strongly preferred juvenile instars of their hosts. The body length differed between parasitised Dictyna and Nigma spiders (medians: 1.95 mm and 2.55 mm, respectively). The distribution of Dictyna and Nigma spiders overlapped along the elevation gradient, but parasitism incidence significantly differed between spider genera along the elevation gradient. Nigma was parasitized at lower elevations between 179-254 m a.s.l. and Dictyna at higher elevations between 361-870 m a.s.l. The phenology of Z. anomala is closely tied to the univoltine life strategy of its host spiders. The parasitoid female oviposits in autumn, and its offspring overwinter as larvae on the host, reach adulthood during spring, and pass the summer as an adult. [ABSTRACT FROM AUTHOR]

The northern yellow sac spider Cheiracanthium mildei L. Koch, is expanding its range to Central Europe, especially to synanthropic habitats. The spiders become unwanted companions because of the unreasonable fear – arachnophobia, and estetic reason – silk retreats in corners, capturing dust. The most commonly used substances against spiders are pesticides, which are, however, toxic. In our work we tested the attraction or repellence of 15 essential oils (EO) from plants representing eight families to C. mildei. Our research has shown a significant repellent effect of EO from three plants, namely Syzygium aromaticum (L.) Merr. et L. M. Perry (Myrtales: Myrtaceae), Ananas comosus (L.) Merr. (Poales: Bromeliaceae) and Musa sp. (L.) (Zingiberales: Musaceae). In contrast, some EOs appeared to have an attraction effect, particularly Carum carvi L. (Apiales: Apiaceae). Zingiber officinale Roscoe (Zingiberales: Zingiberaceae) reduced the tendency of spiders to construct the silken retreat. S. aromaticum, A. sativus, Musa sp. and Z. officinale have the potential to be used as natural repellents against spiders. [ABSTRACT FROM AUTHOR]

Although organic farming was originally promoted as an alternative farming system to address agronomic, environmental and ecological issues, its conventionalisation has led to an intensification and specialisation of production. In the light of this, several studies have questioned the environmental benefits of organic farming as well as its agronomic viability. Thus, there is a need to improve organic vegetable systems to reduce their environmental impact without affecting their productivity. To tackle this challenge, European farmers and researchers have recently started to focus on agroecological service crops (ASCs). However, few studies have simultaneously evaluated the agronomic, environmental and ecological aspects of ASC management under different European pedo‐climatic conditions.We evaluated effects of the ASC management strategies—no‐till roller crimping (NT‐RC) and green manuring (T‐GM) on cropping system performance using agronomic, environmental and ecological indicators—to exemplify the need for multidimensional analysis to understand management implications for addressing environmental and agronomic challenges. We combined the results from 11 organic vegetable field trials conducted in seven European countries over a period of 2 years to test for general trends.Our results provide solid evidence that NT‐RC management across different pedo‐climatic conditions in Europe enhances the activity density of ground and rove beetles and improves both the potential energy recycling within the system and weed control. However, in NT‐RC plots, lower cash crop yield and quality, energetic efficiency of production and activity density of spiders were observed compared to T‐GM.Synthesis and applications. Multidimensional analyses using agronomic, environmental and ecological indicators are required to understand the implications of agricultural management in agroecosystem functioning. Introducing agroecological service crops combined with the use of no‐till roller crimping is a promising strategy for improving agronomic performance (e.g. fewer weeds) and reducing environmental (e.g. increasing the potentially recyclable energy) and ecological (e.g. enhancing the activity density of beneficial taxa such as ground and rove beetles) impacts. However, our study also indicates a need for agronomic and environmental improvements while promoting a wider acceptance of this strategy. [ABSTRACT FROM AUTHOR]

Dispersal is an inseparable feature of animal life and a major determinant of species distributions and range dynamics. However, the role of the genetic architecture of dispersal behaviour, and hence the potential for its evolution in range-expanding species, is poorly understood. Here, we aimed to determine the heritability of dispersal behaviour for an invasive dwarf spider, Mermessus trilobatus , which has undergone rapid range expansion in Europe in the last few decades. Our results showed that spider dispersal traits were repeatable for the parental generation and heritable through both dam and sire. Behaviours were similarly heritable for female and male offspring. Interestingly, offspring of highly dispersive dams and sires exhibited almost three times higher dispersal propensity than offspring of at least one low-dispersive parent. The substantially high dispersal behaviour of the offspring of strictly highly vagile dams and sires indicates its recessive inheritance in this species. Recessive inheritance could favour invasiveness by facilitating high dispersal in inbred founder populations at the invasion front and returning to nonexaggerated mobility soon after an increase in genetic diversity. • Dispersal propensity appeared to be recessively inherited in an invasive spider. • Variation in dispersal was present despite a presumably small founder population. • On average dam and sire contributed to 37% of individual variation in dispersal. • Spiders' dispersal traits were consistent at the individual level. • There is a potential to evolve for high dispersal at the invasion front. [ABSTRACT FROM AUTHOR]

Ecosystems may suffer from the impact of invasive species. Thus, understanding the mechanisms contributing to successful invasions is fundamental for limiting the effects of invasive species. Most intuitive, the enemy release hypothesis predicts that invasive species might be more successful in the exotic range than resident sympatric species owing to the absence of coevolution with native enemies. Here, we test the enemy release hypothesis for the invasion of Europe by the North American spider Mermessus trilobatus. We compare the susceptibility of invasive Mermessus trilobatus and a native species with similar life history to a shared predator with which both species commonly co‐occur in Europe. Contrary to our expectations, invasive Mermessus trilobatus were consumed three times more frequently by native predators than their native counterparts. Our study shows that invasive Mermessus trilobatus is more sensitive to a dominant native predator than local sympatric species. This suggests that the relation between the invasive spider and its native predator is dominated by prey naïveté rather than enemy release. Further studies investigating evolutionary and ecological processes behind the invasion success of Mermessus trilobatus, including testing natural parasites and rapid reproduction, are needed to explain its invasion success in Europe. [ABSTRACT FROM AUTHOR]

Leptonetidae are rarely encountered spiders, usually associated with caves and mesic habitats, and are disjunctly distributed across the Holarctic. Data from ultraconserved elements (UCEs) were used in concatenated and coalescent-based analyses to estimate the phylogenetic history of the family. Our taxon sample included close outgroups, and 90% of described leptonetid genera, with denser sampling in North America and Mediterranean Europe. Two data matrices were assembled and analysed; the first 'relaxed' matrix includes the maximum number of loci and the second 'strict' matrix is limited to the same set of core orthologs but with flanking introns mostly removed. A molecular dating analysis incorporating fossil and geological calibration points was used to estimate divergence times, and dispersal–extinction–cladogenesis analysis (DEC) was used to infer ancestral distributions. Analysis of both data matrices using maximum likelihood and coalescent-based methods supports the monophyly of Archoleptonetinae and Leptonetinae. However, relationships among Archoleptonetinae, Leptonetinae, and Austrochiloidea are poorly supported and remain unresolved. Archoleptonetinae is elevated to family rank Archoleptonetidae (new rank) and Leptonetidae (new status) is restricted to include only members of the subfamily Leptonetinae; a taxonomic review with morphological diagnoses is provided for both families. Four well supported lineages within Leptonetidae (new status) are recovered: (1) the Calileptoneta group, (2) the Leptoneta group, (3) the Paraleptoneta group, and (4) the Protoleptoneta group. Most genera within Leptonetidae are monophyletic, although Barusia , Cataleptoneta , and Leptoneta include misplaced species and require taxonomic revision. The origin of Archoleptonetidae (new rank), Leptonetidae, and the four main lineages within Leptonetidae date to the Cretaceous. DEC analysis infers the Leptoneta and Paraleptoneta groups to have ancestral distributions restricted to Mediterranean Europe, whereas the Calileptoneta and Protoleptoneta groups include genera with ancestral distributions spanning eastern and western North America, Mediterranean Europe, and east Asia. Based on a combination of biology, estimated divergence times, and inferred ancestral distributions we hypothesise that Leptonetidae was once widespread across the Holarctic and their present distributions are largely the result of vicariance. Given the wide disjunctions between taxa, we broadly interpret the family as a Holarctic relict fauna and hypothesise that they were once part of the Boreotropical forest ecosystem. [ABSTRACT FROM AUTHOR]

• Leaf litter in orchards is an important overwintering habitat for biocontrol agents. • There were found six hibernating invertebrate predators on the area of 1 m2. • The vast majority of beneficial species were spiders. • Relationships of hibernating arthropods and environmental conditions were found. • Leaf litter management is a key factor for supporting biological control. Overwintering of invertebrates in Central Europe drives the population dynamics in the subsequent seasons and have the direct impact on ecosystem services and biodiversity conservation. The objective of this study was to investigate the spatial and temporal distribution of overwintering arthropods in the fallen leaves in three fruit orchards. The autumn and early spring distributions of several arthropod taxa were studied in fallen leaves in apple, pear, and cherry orchards in relation to several environmental variables. In the predefined areas (1 x 1 m) samples of fallen leaves were collected in autumn and spring 2018/2019 and 2019/2020. Data from an area of 168 m2 was used for evaluation. A total of 1281 arthropod individuals were collected. The most abundant were spiders with 787 specimens. Samples also comprised 17 other arthropod species or higher taxonomic categories, 10 of which were considered as beneficial, four as pests, and three were unclassified. Spiders were analysed more precisely due to their dominance and their importance in plant protection as biocontrol agents. We demonstrate for the first time that fallen leaves in fruit orchards offer a suitable overwintering microhabitat for predatory arthropods, which contribute to the biological control of pests, and comprehensively evaluate the overwintering arthropod assemblage in relation to several ecological and environmental variables. [ABSTRACT FROM AUTHOR]

Spiders of the genus Micaria are ground‐living mimics of ants. Species delineation in these spiders is challenging, mainly because of exceptional high levels of intraspecific variation masking species boundaries. As implied by preliminary DNA barcode data from Central Europe, the Holarctic and very widely distributed glossy ant‐spider M. pulicaria shows cryptic diversity. Here, we disentangle the hidden diversity by means of an integrative taxonomy approach, using mitochondrial DNA, morphometrics, traditional genitalic characters and ecology. Our data suggest the clear delineation of two distinct species, which supports the conception of 19th century taxonomists. These early naturalists distinguished M. pulicaria and a second closely related species based on morphology and natural history, which were synonymized in subsequent taxonomic studies. Therefore, we re‐circumscribe M. pulicaria and revalidate the long forgotten M. micans. These two Micaria species co‐occur sympatrically in vast areas of the western Palearctic, while the Nearctic region is populated by M. pulicaria alone. Male genitalic traits are more dissimilar in the area of sympatry than in allopatry, suggesting a decisive role of reproductive character displacement in species diversification. Our study emphasizes the value of the early taxonomic literature in integrative taxonomic studies, as it may contain crucial information on natural history that are not regularly recorded by modern taxonomists. [ABSTRACT FROM AUTHOR]

Macroecologists seek to identify drivers of community turnover (β-diversity) through broad spatial scales. However, the influence of local habitat features in driving broad-scale β-diversity patterns remains largely untested, owing to the objective challenges of associating local-scale variables to continental-framed datasets. We examined the relative contribution of local- versus broad-scale drivers of continental β-diversity patterns, using a uniquely suited dataset of cave-dwelling spider communities across Europe (35–70° latitude). Generalized dissimilarity modelling showed that geographical distance, mean annual temperature and size of the karst area in which caves occurred drove most of β-diversity, with differential contributions of each factor according to the level of subterranean specialization. Highly specialized communities were mostly influenced by geographical distance, while less specialized communities were mostly driven by mean annual temperature. Conversely, local-scale habitat features turned out to be meaningless predictors of community change, which emphasizes the idea of caves as the human accessible fraction of the extended network of fissures that more properly represents the elective habitat of the subterranean fauna. To the extent that the effect of local features turned to be inconspicuous, caves emerge as experimental model systems in which to study broad biological patterns without the confounding effect of local habitat features. [ABSTRACT FROM AUTHOR]

Background Spiders (Arachnida: Araneae) are widespread in subterranean ecosystems worldwide and represent an important component of subterranean trophic webs. Yet, global-scale diversity patterns of subterranean spiders are still mostly unknown. In the frame of the CAWEB project, a European joint network of cave arachnologists, we collected data on cavedwelling spider communities across Europe in order to explore their continental diversity patterns. Two main datasets were compiled: one listing all subterranean spider species recorded in numerous subterranean localities across Europe and another with high resolution data about the subterranean habitat in which they were collected. From these two datasets, we further generated a third dataset with individual geo-referenced occurrence records for all these species. New information Data from 475 geo-referenced subterranean localities (caves, mines and other artificial subterranean sites, interstitial habitats) are herein made available. For each subterranean locality, information about the composition of the spider community is provided, along with local geomorphological and habitat features. Altogether, these communities account for > 300 unique taxonomic entities and 2,091 unique geo-referenced occurrence records, that are made available via the Global Biodiversity Information Facility (GBIF) (Mammola and Cardoso 2019). This dataset is unique in that it covers both a large geographic extent (from 35° south to 67° north) and contains high-resolution local data on geomorphological and habitat features. Given that this kind of high-resolution data are rarely associated with broad-scale datasets used in macroecology, this dataset has high potential for helping researchers in tackling a range of biogeographical and macroecological questions, not necessarily uniquely related to arachnology or subterranean biology. [ABSTRACT FROM AUTHOR]

Peat bogs are highly endangered and very sensitive habitats in Central Europe. Their high water table, acidity and characteristic climate determine their specialized flora and fauna with numerous rare species. Peat bogs are threatened by soil erosion and nutrient infiltration due to forestry management or grazing. Several small, natural peat bogs exist in the Carpathians, mainly covered with birch and pine forests. Here we assessed the effect of geological location, peat bog size and tree species on the spider fauna. We collected spiders with pitfall traps in eight peat bogs in Eastern Transylvania. We identified several species of high nature conservation value, regarded to be rare in the Central-European fauna. We found higher species richness, abundance and diversity in birch forests than in pine forests. The open canopy of birch forests may allow open habitat specialists to occur in high densities in these forests. Species composition was affected by geological location, indicating that the regional fauna of peat bogs in different mountain ranges are isolated. However, we found no significant effect of habitat area on spider assemblages, the valuable tyrphophilic spider fauna was present even in the smallest peat bog. Peat bog spider fauna requires specific habitat conditions, we suggest that preserving hydrological properties and water quality even in the smallest bogs would conserve the specialized fauna. [ABSTRACT FROM AUTHOR]

The as yet unknown egg sac and clutch of Paratrachelas maculatus (Thorell, 1875) is described together with new records of the species from Germany and Austria. The flat, lens-like egg sacs contained 5 to 7 eggs, each approximately 0.75 mm in diameter, and were camouflaged with substrate by the female. Based on known records and locations, the species is most probably established in urban regions of Central Europe. [ABSTRACT FROM AUTHOR]

[Display omitted] • The genus Mastigusa is for the first time included in a phylogenetic analysis. • Mastigusa belongs to the family Cybaeidae and not Hahniidae. • Mastigusa is closely related to the genus Cryphoeca. • The genus Mastigusa shows an unexpected genetic diversity. The palearctic spider genus Mastigusa Menge, 1854 is characterized by a remarkable morphology and wide ecological variability, with free-living, cave dwelling and myrmecophile populations known. This genus has a long and tangled taxonomic history and was placed in different families in the past, all belonging to the "marronoid clade", an informal grouping of families characterized by the lack of strong synapomorphies. Three species are currently recognized, but their identity and circumscription has been long debated. A molecular approach was never applied for trying to solve these uncertainties, and doubts still remain both about its phylogenetic placement and about the taxonomic status of the described species. For the first time the genus Mastigusa is included in a molecular phylogenetic analysis and strong support is found for its placement within the family Cybaeidae, in sister relationship with the genus Cryphoeca Thorell, 1870. An analysis of Mastigusa populations spanning across the distribution range of the genus identifies a high and previously overlooked genetic diversity, with six distinct genetic lineages showing a strong geographic pattern. Divergence times between Mastigusa and its sister genus and between the distinct Mastigusa lineages are estimated, and the groundwork is laid for a taxonomic revision of the species belonging to the genus. [ABSTRACT FROM AUTHOR]

Reconciling biodiversity conservation with agricultural production requires a better understanding of how key ecosystem service providing species respond to agricultural intensification. Carabid beetles and spiders represent two widespread guilds providing biocontrol services. Here we surveyed carabid beetles and spiders in 66 winter wheat fields in four northwestern European countries and analyzed how the activity density and diversity of carabid beetles and spiders were related to crop yield (proxy for land-use intensity), percentage cropland (proxy for landscape complexity) and soil organic carbon content, and whether these patterns differed between dominant and non-dominant species. <17 % of carabid or spider species were classified as dominant, which accounted for >90 % of individuals respectively. We found that carabids and spiders were generally related to different aspects of agricultural intensification. Carabid species richness was positively related with crop yield and evenness was negatively related to crop cover. The activity density of non-dominant carabids was positively related with soil organic carbon content. Meanwhile, spider species richness and non-dominant spider species richness and activity density were all negatively related to percentage cropland. Our results show that practices targeted to enhance one functionally important guild may not promote another key guild, which helps explain why conservation measures to enhance natural enemies generally do not ultimately enhance pest regulation. Dominant and non-dominant species of both guilds showed mostly similar responses suggesting that management practices to enhance service provisioning by a certain guild can also enhance the overall diversity of that particular guild. [ABSTRACT FROM AUTHOR]

Winter-active arthropod predators (like vegetation-dwelling spiders) significantly suppress pest populations during winter in pome fruit orchards in Central Europe. Clubiona spiders are very abundant in orchards and have been observed to be active during winter. Here, we performed laboratory experiments to assess the movement and predation activity of clubionids at low temperatures. In addition, we also assessed prey survival (psyllids and crickets). We revealed that Clubiona spiders actively moved even at a temperature below 0 °C. Pest prey (Cacopsylla sp.) was able to survive at low temperatures, but crickets died at 3 and -1 °C. Overall Clubiona activity was very low but present during the whole observation period of five days. The predation activity of Clubiona declined with lower temperatures for both cricket and pest (Cacopsylla sp.) prey. Nevertheless, 44% and 25% of Clubiona individuals captured and consumed psyllid and cricket prey, respectively, even at the lowest temperature of −1 °C. Our results show that Clubiona spiders are active predators at low temperatures and, therefore, should contribute to the suppression of overwintering pest populations. • Clubiona spiders are common arthropod predators in pome fruit orchards. • Clubiona spiders remain active and even capture pest prey at temperatures below 0 °C. • Therefore, Clubiona spiders have the potential to contribute to pest control during winter. [ABSTRACT FROM AUTHOR]

Purse-web spiders Atypus spp. (Araneae: Atypidae) are the only representatives of the archaic spider infraorder Mygalomorphae in the Central European fauna. These burrow-dwelling spiders are red-listed in all Central European countries. Atypus muralis occurs on relics of continental steppes, Atypus piceus on dry submediterranean grassland and dry herb-rich forest fringes, while Atypus affinis inhabits sparse dwarf dry forests, usually those dominated by oaks. Long-term sustainability of their habitats in the relatively humid Central European climate was maintained by grazing. Since the 1950s, pasturing was terminated across most of Central Europe, which led to immediate overgrowth of pastures by aggressive grasses and woody plants. Grazing was later reinstated in some reserves, but in cases of poorly controlled grazing intensity, footsteps had immediate detrimental effects on the residual populations of purse-web spiders and other invertebrates. Therefore, grazing intensity needs to be regulated, considering its double-edge effects on the biota of xerothermophilic habitats. Nests of European Atypus species have never been found in habitats subject to recent or even regular distribution. Therefore, they may serve as reliable indicators of well preserved xerothermic habitats. Their nests are easy to detect, and the European Atypus spiders can be utilized as model species for monitoring impacts of conservation management. Monitoring population dynamics of Atypus requires establishing permanent study plots of uniform size, documentation of vegetation by phytocenological relevé, counting their density (number of purse-webs found in the plot) and age structure (diameter of purse webs). [ABSTRACT FROM AUTHOR]

The study of courtship behavior provides a useful tool for identifying cryptic species due to the qualitative differences that can be observed in closely related species. Here, we present an overview of visual courtship displays of 26 European species of the genus Pardosa C.L. Koch 1847, including new quantitative and qualitative data. Thirty-five recurring courtship elements are described and illustrated by means of drawings, photos and videos (available online). In general terms, complex movements of the palps, the first pair of legs and the abdomen characterize courtship displays in the genus Pardosa. The most complex movements are performed by the palps, while legs and abdomen mainly oscillate in the air or vibrate on the substrate. We noticed a high level of complexity in almost all of the species, both in terms of sensory modes involved and number of courtship elements composing the displays. No apparent relationships emerged when considering ethological similarities among species, attesting to the relative independence between morphological and ethological characters. [ABSTRACT FROM AUTHOR]

European forest management guidelines include conservation and enhancement of biodiversity. Within plantation forestry, trackways provide contiguous permanent open-habitat with potential to enhance biodiversity. We examined the ground-active spider assemblage in the trackway network of Thetford Forest, Eastern England, the largest lowland conifer forest in the UK, created by afforestation of heathland and farmland. Results are relevant to other forests in heath regions across Europe. We used pitfall trapping to sample the spider assemblage of trackways within thicket-aged stands (n = 17), mature stands (n = 13) and heathland reference sites (n = 9). A total of 9,314 individuals of 71 species were recorded. Spider assemblages of the trackway network were distinct from those of the heathland reference sites; however, trackways were found to support specialist species associated with grass-heath habitats, including nationally scarce species. Richness of grass-heath species was similar for trackways in thicket-aged forest and heathland reference sites, although the abundance of individuals was three times greater in the reference sites. Trackways in mature stands had lower grass-heath species richness and abundance than both thicket trackways and heath reference sites. Wide trackways within thicket stands contained greater richness and abundance of specialist xeric species than narrower trackways. However, fewer xeric individuals were found in trackways compared to heathland reference sites. Either inferior habitat quality in trackways or poor dispersal ability of specialist xeric species may largely restrict these to relict areas of heathland. Targeted widening of trackways to allow permanent unshaded habitat and creating early successional stages by mechanical disturbance regimes could improve trackway suitability for specialist species, helping to restore connectivity networks for grass-heath biodiversity. [ABSTRACT FROM AUTHOR]

We study how species richness of arthropods relates to theories concerning net primary productivity, ambient energy, water-energy dynamics and spatial environmental heterogeneity. We use two datasets of arthropod richness with similar spatial extents (Scandinavia to Mediterranean), but contrasting spatial grain (local habitat and country). Samples of ground- dwelling spiders, beetles, bugs and ants were collected from 32 paired habitats at 16 locations across Europe. Species richness of these taxonomic groups was also determined for 25 European countries based on the Fauna Europaea database. We tested effects of net primary productivity (NPP), annual mean temperature (T), annual rainfall (R) and potential evapotranspiration of the coldest month (PETmin) on species richness and turnover. Spatial environmental heterogeneity within countries was considered by including the ranges of NPP, T, R and PETmin. At the local habitat grain, relationships between species richness and environmental variables differed strongly between taxa and trophic groups. However, species turnover across locations was strongly correlated with differences in T. At the country grain, species richness was significantly correlated with environmental variables from all four theories. In particular, species richness within countries increased strongly with spatial heterogeneity in T. The importance of spatial heterogeneity in T for both species turnover across locations and for species richness within countries suggests that the temperature niche is an important determinant of arthropod diversity. We suggest that, unless climatic heterogeneity is constant across sampling units, coarse-grained studies should always account for environmental heterogeneity as a predictor of arthropod species richness, just as studies with variable area of sampling units routinely consider area. [ABSTRACT FROM AUTHOR]

Northwest Europe's largest heather-dominated sandy habitats are located in the nature reserve Lüneburger Heide, Germany. Yet, even these appear to be losing their ability to support some of their stenotopic species such as the ladybird spider, Eresus kollari Rossi 1846, and are thus becoming increasingly important for the preservation of these species. The habitat requirements of this endangered spider species were investigated in order to obtain data that will help stabilize the last remnants of the species' population in northwest Germany. Several heathland habitats were surveyed by pitfall trapping during the mate-search period of the males. Two statistical methods were applied: logistic regression and boosted regression trees (BRT). Both methods showed that three habitat variables are of prime relevance in predicting the occurrence of E kollari: a) thickness of the organic layer (a negative effect), b) soil temperature at a depth of 10 cm, and c) Calluna cover in the herb layer (both have positive effect). Our results show that choppering (removing above-ground biomass and most of O-layer) and burning are likely appropriate heathland management measures for the conservation of E. kollari. Such measures improve the species' habitat quality by creating a heterogenic (small-scaled) heathland structure with suitable microhabitats. As Calluna heathlands show a clear senescence of the dominant heather, it is essential that those habitat patches be conserved. Further measures, such as transfer experiments, are recommended. [ABSTRACT FROM AUTHOR]

We used canopy fogging to study the high (20-26 m), intermediate (13-19 m) and low (5-6 m) strata in three European beech patches ( Fagus sylvatica) in nine months (2005-2007) and estimate species richness and diversity of arboreal spiders. Eight species (10%) were previously unseen in European beech trees, and one of these is likely a new species. Moreover, two species are on the Bavarian red list. Our results revealed that the high stratum of the old-growth trees provided unique resources and possessed the greatest diversity and evenness, whereas intermediate and low strata had high similarity in respect to diversity, dominance, species, and family composition. Since the majority of beech forests consists of mature and young trees in Central Europe, and old-growth forests are rarely preserved, we recommend young beech be used in a sampling protocol for rapid biodiversity assessment. However, adding samples from the two higher strata to the lowest stratum (55 species), almost doubled the estimated species richness (102 species). This suggests that the lower stratum alone does not represent a true image of the total canopy fauna inventory in this, and likely other, beech stands. To complete this comprehensive inventory in European beeches, the Chao1 predicted that additional sampling would be needed in the highest stratum, where there is a high probability to find previously undetected species in a next survey. Our study clearly shows that neglecting the crowns of the largest, tallest trees risks underestimating the overall spider diversity in Central European forests. [ABSTRACT FROM AUTHOR]

A new troglobitic species, Nesticus baeticus sp. n. (⚰⚮), inhabiting the karst landscapes of the high part of the Cazorla, Segura and Las Villas Natural Park (NE Jaén, Spain) where it has been found in 8 caves is diagnosed and described, its distribution and habitat are also analyzed. The new species belongs to the Iberian species group that includes N. luquei, N. lusitanicus and N. murgis. Evolutionary relationships of the Iberian Nesticus species are discussed on the basis of morphological and molecular data (cox1 and rrnL). [ABSTRACT FROM AUTHOR]

In order to increase our arachnological knowledge of Greece, and in particular north-east Greece, an investigation of the arachnofauna of the Aladjagiola wetland complex was conducted from April to July 2008. The study area is part of the Nestos Delta in north-east Greece, and comprises an area of approximately 20 km. Spiders were collected from 28 sites using pitfall traps. In all, 6694 specimens were sampled, including 206 species from 31 families. Altogether, 30 and 74 species were new to the districts of Greece and Macedonia, respectively. A number of faunistically interesting species were recorded during the study: Brachythele denieri (Simon, 1916), Camillina metellus (Roewer, 1928), Zelotes cingarus (O.P.-Cambridge, 1874), Zodarion blagoevi Bosmans, 2009, Zodarion epirense Brignoli, 1984, Zodarion hauseri Brignoli, 1985, and Zodarion pirini Drensky, 1921, are Balkan endemics; Tegenaria angustipalpis Levy, 1996 and Titanoeca turkmenia Wunderlich, 1995 were newly discovered in Europe. Widespread elements represented the largest share of the species inventory, although chorological analysis indicated that the study area, as well as the whole north-eastern part of Greece, is a reflection of a transition zone from the European fauna towards the Mediterranean and eastern (or Ponto-Anatolian) elements. Taken in combination, these affect the local fauna. The Balkan endemics, although small in number of species, further underline the unique identity of the area. Based on comparisons with data sets from the country's southernmost island, i.e. Crete, Greece can be regarded as a zoogeographical gradient. Hereby, Aladjagiola represents the northern edge, with European and Anatolian elements dominating the species inventory, and Crete represents the southern edge, with widespread but also endemic Mediterranean and eastern elements creating a more local and insular zoogeographical character. In conclusion, Greece cannot be viewed as a uniform zoogeographical unit, but rather as a mosaic of various regional zoogeographical patterns. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, , 217-233. [ABSTRACT FROM AUTHOR]

A total of 47 spider species are alien to Europe; this corresponds to 1.3 % of the native spider fauna. They belong to (in order of decreasing abundance) Theridiidae (10 species), Pholcidae (7 species), Sparassidae, Salticidae, Linyphiidae, Oonopidae (4-5 species each) and 11 further families. There is a remarkable increase of new records in the last years and the arrival of one new species for Europe per year has been predicted for the next decades. One third of alien spiders have an Asian origin, one fith comes from North America and Africa each. 45 % of species may originate from temperate habitats and 55 % from tropical habitats. In the past banana or other fruit shipments were an important pathway of introduction; today potted plants and probably container shipments in general are more important. Most alien spiders established in and around human buildings, only few species established in natural sites. No environmental impact of alien species is known so far, but some alien species are theoretically dangerous to humans. [ABSTRACT FROM AUTHOR]

This short note on Oecobius amboseli Shear & Benoit, 1974 presents photographs of the species in Egypt, discusses its distribution in the world, and states the identification of Oecobius sp. in Murphy & Roberts (2015). [ABSTRACT FROM AUTHOR]

1. Biotic invasions are one of the most important reasons for changes in biodiversity. The alien sheetweb spider Mermessus trilobatus (Araneae: Linyphiidae) has become abundant in large parts of Central Europe within the past three decades. Its invasion might negatively influence native spiders, for instance via competition for webs. 2. Laboratory experiments were developed to test if M. trilobatus is competitively superior to native spiders. The alien M. trilobatus and five native sheetweb spiders ( Erigone dentipalpis, E. atra, Gnathonarium dentatum, Dicymbium nigrum and Micrargus herbigradus) were compared with respect to their success to take over occupied webs from E. dentipalpis. 3. The rate of web takeover or defence was determined by body size, whereby individuals with a wider thorax invaded webs more successfully. After taking body size into account, the frequency of defence or web takeover did not differ between species. In 13% of all confrontations, predation against generally smaller opponents was recorded. Contrary to the predictions, raising the web value with food resources did not raise the effort expended on web defence but reduced predation by the web owner. 4. The current study does not indicate that the invasion of the relatively small-sized M. trilobatus is facilitated by strong competitiveness. Nevertheless, M. trilobatus may displace smaller-sized immature specimens and thereby threaten native spiders. Still, other reasons are likely to underlie the success of M. trilobatus in Europe, such as rapid reproduction or release from natural enemies. [ABSTRACT FROM AUTHOR]

Selected life-history traits of an oonopid spider, Triaeris stenaspis Simon, which has been introduced into greenhouses in Europe, were investigated. Spiders were reared in the laboratory under constant physical and dietary conditions, and followed from egg to death. The spiders passed through 3 juvenile instars, each lasting approximately a month. The adult stage lasted on average 6 months, which is 54% of the entire life cycle. The mortality in each juvenile instar was similar. Five morphological characters were recorded for each instar, which provided a reliable means of identifying the developmental stages. All spiders developed into females and although kept isolated they laid fertile eggs, which indicates thelytokous parthenogenesis. Eggs were always enclosed in a disc-shaped egg-sac, each containing 2 eggs. Total fecundity was on average 27 eggs and rate of laying eggs decreased with age. Fecundity was positively correlated with adult longevity. Fertility was rather low, approximately 59%. It was negatively correlated with fecundity but not related to longevity. Low fertility appears to be the only cost of parthenogenetic reproduction. There was considerable genotypic variation in all traits studied compared to that in sexually reproducing spiders. There were no apparent maternal effects on all the traits studied. Using molecular methods proved that parthenogenesis in T. stenaspis is not induced by the endosymbiotic bacteria, Wolbachia sp. or Cardinium sp. [ABSTRACT FROM AUTHOR]

We analysed the pattern of covariation of European spider species richness with various environmental variables at different scales. Four layers of perception ranging from single investigation sites to the whole European continent were selected. Species richness was determined using published data from all four scales. Correlation analyses and stepwise multiple linear regression were used to relate richness to topographic, climatic and biotic variables. Up to nine environmental variables were included in the analyses (area, latitude, elevation range, mean annual temperature, local variation in mean annual temperature, mean annual precipitation, mean July temperature, local variation in mean July temperature, plant species richness). At the local and at the continental scale, no significant correlations with surface area were found, whereas at the landscape and regional scale, surface area had a significant positive effect on species richness. Factors that were positively correlated with species richness at both broader scales were plant species richness, elevation range, and specific temperature variables (regional scale: local variation in mean annual, and mean July temperature; continental scale: mean July temperature). Latitude was significantly negatively correlated with the species richness at the continental scale. Multiple models for spider species richness data accounted for up to 77% of the total variance in spider species richness data. Furthermore, multiple models explained variation in plant species richness up to 79% through the variables mean July temperature and elevation range. We conclude that these first continental wide analyses grasp the overall pattern in spider species richness of Europe quite well, although some of the observed patterns are not directly causal. Climatic variables are expected to be among the most important direct factors, although other variables (e.g. elevation range, plant species richness) are important (surrogate) correlates of spider species richness. [ABSTRACT FROM AUTHOR]

Global trade is permanently ongoing and increases its volume every year. In this study, the occurrence of 87 unintentionally introduced spider species alien to Europe is analysed. The analysis includes (1) the introduction potential of six different origin areas of the world according to trade volume, area size, and geographical distance; (2) the body size of native and alien species; and (3) occurrence in or at buildings (synanthropic) or in natural habitats. We found the eastern Palearctic as the most influencing origin area with 44 introduced spider species to Europe. The eastern Palearctic and the Indomalayan provided a significantly higher number of introductions than expected, whereas the Nearctic, Neotropical, and Afrotropical provided a significantly lower number of introduced species than expected. This can be explained with their lower trade volume, smaller area, larger geographical distance to Europe, and stronger climate differences to Europe. Comparing the body size of introduced and native European spider species of the same family, we found for Theridiidae significantly larger alien spiders and for all other tested families a trend to a larger body size of alien species compared to the native spiders. The family affiliation of alien spiders is the most important factor for synanthropic occurrence in Europe. On the base of a very conservative estimation of spider species introductions to Europe combined with possible effects of climate change, we predict for the near future a permanent increase in the number of alien spider species in Europe. [ABSTRACT FROM AUTHOR]

The winter activity of spiders and pseudoscorpions, recorded during ten years (1994–2003) in the Dolomites and the Venetian Pre-Alps, is reported. The family Linyphiidae s.l. showed the highest number of active species, 69% of the total, and 88% of all the collected specimens. The spider Lepthyphantes cristatus was the most abundant species, including 42% of the individuals. Data on the families' abundance and phenology are compared with previous observations from Canada and Northern Europe. [ABSTRACT FROM AUTHOR]

The eresid spider genus Eresus is morphologically and ecologically conservative. At least three species occur in Europe. However, deep genetic divergence among geographical samples within two species, E. cinnaberinus and E. sandaliatus, may suggest more cryptic species. In the present study we investigate the genetic cohesion of the third species, Eresus walckenaeri, throughout its eastern Mediterranean distribution range, relative to the E. cinnaberinus–E. sandaliatus species complex. Eresus walckenaeri specimens were monophyletic. Genetic discreteness of E. walckenaeri in a region of sympatry with its sister species in Greece provides evidence for species integrity of E. walckenaeri within the European Eresus species complex. Eresus walckenaeri exhibited high concordance between geographical location and mtDNA genealogy. Two major phylogeographical clades were found in the Greek–Turkish and Syrian–Israel parts of the investigated area, respectively (∼6.5% sequence divergence). Concordance between geography and genetic divergence was further observed between Aegean island samples and their corresponding Greek and Turkish mainland samples, suggesting regional subdivision with gradual but potentially high dispersal propensity. Monophyly and limited regional distribution indicate Mediterranean endemic origin. © 2005 The Linnean Society of London, Biological Journal of the Linnean Society, 2005, 86, 1–9. [ABSTRACT FROM AUTHOR]

Habitat use, diet and food supply of European Golden PloverPluvialis apricariachicks were studied on blanket bog in the South Pennines, UK. The home ranges occupied by chicks until fledging averaged 40 ha; they contained relatively more cotton grass and bare peat than was available generally, but less heather and grassland. Use of BilberryVaccinium myrtillusand CrowberryEmpetrum nigrumincreased with age, whereas that of cotton grassEriophorumspp. declined. Dietary composition, as assessed by faecal analysis, was similar to that obtained from the crops of dead birds. The diet of younger chicks, assessed by dry weight of prey, consisted of about 30% each of adult and larval tipulids, whereas for chicks older than 16 days, about 70% was tipulid larvae. Beetles, spiders and caterpillars each comprised 5–20% of the diet, depending on age. Older chicks took larger prey. The exploitation of larval tipulids was correlated positively with the chicks’ use of cotton grass and bare peat areas, whereas caterpillars, beetles and spiders were more often taken from dwarf shrubs, reflecting variation in prey abundance. Bare peat was an important foraging habitat, whose exploitation was associated positively with the growth rate of young chicks, and with mean prey size. Both weight gain and survival of young chicks were positively correlated with the abundance of tipulid adults, confirming the hypothesis that the flush of tipulid hatching is an important determinant of breeding success. Golden Plover chicks are capable of considerable movements to track variation in prey availability. This behaviour is likely to be an important survival strategy facilitating the utilization of a mosaic of cotton grass and dwarf shrub habitats. Appropriate rotational strip-burning or grazing management could be used to create and maintain such habitats. [ABSTRACT FROM AUTHOR]

Predators of apple and pear pests in northern and central Europe and their use as biological control agents are reviewed. Many natural enemy species are specialized feeders and are able to respond to the population dynamics of particular pest species. The most oustandingly successful example of this is the use of phytoseiid mites, particularly Typhlodromus pyri, against phytophagous pest mites in apple. This mite management strategy is now widespread throughout European apple growing regions. Another example is the use of Anthocoris nemoralis against pear psyllids, Cacopsylla pyricola and C. pyri. Several groups of naturally occurring polyphagous predators, such as chrysopids, coccinellids, syrphids and spiders, also prey on a number of pest species in orchards, contributing generally to the reduction in pest populations. However, they are unlikely alone to prevent pest damage fully and reliably. In seeking biological control opportunities for a particular pest, these polyphagous natural enemies are unlikely to be a high priority. An exception, due to its abundance in orchards, is the common earwig, Forficula auricularia, although this predator may also cause some fruit injury. Another option to consider when reviewing possibilities for biological control in orchards is the introduction of biological control agents. The success rate of this approach, using arthropod predators to control pests of field crops, has been generally poor. Furthermore, mass production methods for predators are likely to be difficult and very costly. The biological supplies industry is constantly seeking culture techniques, largely for arthropod biological control agents of pests of protected crops. It is possible that some future advance may be relevant to orchards, though currently available predators do not appear promising. A careful economic appraisal of the feasibility of use of any potential biological control agent would be prudent before embarking on research. [ABSTRACT FROM AUTHOR]

Species traits are an essential currency in ecology, evolution, biogeography, and conservation biology. However, trait databases are unavailable for most organisms, especially those living in difficult-to-access habitats such as caves and other subterranean ecosystems. We compiled an expert-curated trait database for subterranean spiders in Europe using both literature data (including grey literature published in many different languages) and direct morphological measurements whenever specimens were available to us. We started by updating the checklist of European subterranean spiders, now including 512 species across 20 families, of which at least 192 have been found uniquely in subterranean habitats. For each of these species, we compiled 64 traits. The trait database encompasses morphological measures, including several traits related to subterranean adaptation, and ecological traits referring to habitat preference, dispersal, and feeding strategies. By making these data freely available, we open up opportunities for exploring different research questions, from the quantification of functional dimensions of subterranean adaptation to the study of spatial patterns in functional diversity across European caves., (© 2022. The Author(s).)

In the last decades, the transformation of agriculture and the associated decline in semi-natural grasslands have been major drivers of the loss of spider diversity across Europe, in particular in mountain regions. In the early stages of forest succession, abandoned grasslands exhibit a complex vegetation structure sharing environmental conditions with both open habitats and forests. At the landscape scale, the occurrence of abandoned patches can potentially provide novel habitats and niches for ground-dwelling spiders. Here, we used two complementary methods: traditional species diversity analyses and species-habitat networks to understand how abandoned grasslands can interact with the surrounding habitat mosaic in supporting spider communities. We selected six landscapes along an elevational gradient and sampled spiders in all the major agricultural and semi-natural habitats occurring across the landscapes. At all elevations, we found a similar species richness and activity density between agricultural habitats (i.e. meadows, pastures, and crop fields) and abandoned grasslands. On the contrary, we consistently found lower species richness and activity density in forests than in all open habitats. Despite the similar diversity between open habitats, most species-habitat networks exhibited a high and constant modularity, i.e. the same species tended to occur in a specific habitat type and not in the others. Only a few species were shared between abandoned and agricultural habitats, indicating that abandoned grasslands cannot support populations of most species typical of open managed habitats. Early abandoned patches increased landscape habitat heterogeneity providing unique niches to spider species that, however, rarely occur in other habitats. The maintenance of multiple habitat types across the landscape is expected to increase the regional species pool, while the role of abandoned patches as surrogate habitat for the conservation of spider species typical of semi-natural grasslands appeared limited. Similarly, abandoned patches are not expected to help maintaining the populations of spider species occurring in agricultural habitats. • Similar species richness and activity density were observed between abandoned and agriculturally managed habitats. • Species-habitat networks exhibited a high and constant modularity suggesting high habitat specialization. • Abandoned patches did not help maintaining populations of spider species typical of agricultural habitats. • The maintenance of multiple habitats across the landscape increases regional spider species pool. [ABSTRACT FROM AUTHOR]

• We studied effect of coppice management restoration on spiders in oak forest reserve. • Species and functional richness of spiders increased towards to strong thinning. • Conservation valuable species occurred in all management treatments. • Non-intervention management was supportive for forest ubiquitous species. • Return to active coppice management can be a successful conservation strategy. Lowland forests of Central Europe had been managed by diverse traditional practices for millennia. Such management helped to maintain heterogeneous habitat conditions suitable for a wide variety of arthropod species. Modern approaches to conservation, however, with their strategies of nonintervention, unintentionally caused an overall habitat homogenization within protected areas in many ecosystem types during the 20th century. As a result, the diversity of organisms, including several large groups of arthropods, has gradually declined. Active interventions that would diversify homogenized lowland forest reserves are increasingly being reintroduced. A question remains as to whether the traditional management restoration at various intensities will maintain conditions suitable for high diversity of functionally important groups of arthropods. Here, we studied the effect of canopy thinning, aimed at coppice restoration, on ground-dwelling spider assemblages. Sampling was based on experimental plots distributed equally in an abandoned coppice-with-standards among three canopy thinning intensities: strong thinning, moderate thinning, and nonintervention as a control. We recorded 116 species of spiders, including a high proportion of Red-listed and threatened species. The species richness and presence of rare and threatened species increased with the intensity of canopy thinning. The abundance of spiders was greater in plots with moderate thinning than in control plots. Functional richness was greatest in open habitats with strong canopy thinning, however functional traits were equally distributed across all habitats. Although ordination analyses revealed that species of conservation concern tended to be associated with open habitats, some conservation-valuable species had affinities also for nonintervention plots. Overall, our results indicated that the best silviculture practice for biodiversity conservation is a combination of various management intensities that would support functional groups ranging from open habitat specialists to species typical for dense and more humid forest patches. We demonstrated that returning to active coppicing management can be a successful strategy for biodiversity restoration in lowland forests. [ABSTRACT FROM AUTHOR]

Despite their ecological importance and diversity, spiders (Arachnida: Araneae) are underrepresented in conservation policies in comparison to other groups. We review all extant conservation tools focusing on spiders in Europe, highlighting general patterns, limitations, gaps, and future directions. We assembled a comprehensive online database reporting all available information concerning the legal protection and conservation status of 4,154 spider species. Existing international legislation has limited coverage, with only one species listed in the Bern Convention and EU Habitats Directive. At the national and subnational levels, 178 species are formally mentioned in the legislation of 19 European countries. Moreover, the International Union for Conservation of Nature (IUCN) includes assessments for 301 species worldwide, 164 of these threatened and eight native to Europe. In addition, spiders are mentioned in Regional Red Lists and Red Books in 28 out of 42 European countries considered in this review. Northern and Central European countries have the highest percentage of species assessed at the regional level in Red Lists and Red Books. The Mediterranean basin has the highest spider diversities in Europe but conservation efforts are lacking, both in terms of assessments and national or subnational legislation. Among European species, Dolomedes plantarius , Argyroneta aquatica and Eresus kollari are the most frequently mentioned in European conservation measures, possibly due to their ecological traits and their strict association with declining habitats. Considering the current threats to spiders in Europe, the protection of large areas of suitable habitat should be considered as the most effective approach to spider conservation. • Spiders are largely underrepresented in conservation policies in Europe. • Only one spider species is listed in the Bern Convention and EU Habitats Directive. • 178 species of spiders are mentioned in the legislation of 19 European countries. • 28 European countries have spider Red Lists or Red Books. • Conservation efforts are lacking in Mediterranean countries. [ABSTRACT FROM AUTHOR]

Patterns of changes of spider assemblages in relation to various conservation management methods in xeric grassland. • Effects on spiders of small-scale management methods were studied in xeric grassland. • Prescribed burning increased spider diversity and supported rare xeric species. • Use of no active management was supportive to vegetation-dwelling spiders. • We suggest to maintain xeric grasslands by combining small-scale management methods. Seminatural grasslands are among the most valuable habitats for arthropod conservation in Central Europe. The abandonment of traditional farming has caused these areas to become overgrown and homogeneous, thereby resulting in loss of arthropod biodiversity. This traditional farming therefore needs to be complemented by active conservation management methods. An important question is whether small-scale conservation management may support arthropod diversity and habitat specialists inhabiting abandoned seminatural grasslands. We investigated the effects of mowing, prescribed burning, mechanical turf disturbance, and absence of active management on species richness, functional diversity and composition, conservation value, abundance of Red List species, and assemblage composition of spiders. The management methods were applied on small-scale (4 × 5 m) patches in protected xeric grassland. Spiders were sampled using pitfall traps and sweeping during 2017 and 2018. A total of 11,634 specimens from 154 species were recorded, including many rare and threatened species. The temporal responses of spider assemblages to active conservation management depended on the particular group of spiders. Changes in assemblage composition and resulting shifts in the community weighted mean values were distinct in the second year of the experiment. Management had no significant effect on the species richness of ground-dwelling spiders. Mechanical turf disturbance shifted the assemblage composition of ground-dwelling spiders towards habitat generalist species. Vegetation-dwelling spiders had the highest species richness in unmanaged patches. Their functional diversity was lower in disturbed patches. Burnt patches supported species of conservation concern for both spider groups. Prescribed burning had positive results for most of the studied indicators. Nevertheless, mechanical turf disturbance had a rather negative effect on the spider assemblages. Our results indicate that even small, patch-like interventions with minimal costs can considerably support the valuable spider assemblages of xeric grassland in the intensified landscape of Central Europe. [ABSTRACT FROM AUTHOR]

Insects are the most ubiquitous and diverse group of eukaryotic organisms on Earth, forming a crucial link in terrestrial and freshwater food webs. They have recently become the subject of headlines because of observations of dramatic declines in some places. Although there are hundreds of long-term insect monitoring programs, a global database for long-term data on insect assemblages has so far remained unavailable. In order to facilitate synthetic analyses of insect abundance changes, we compiled a database of long-term (≥10 yr) studies of assemblages of insects (many also including arachnids) in the terrestrial and freshwater realms. We searched the scientific literature and public repositories for data on insect and arachnid monitoring using standardized protocols over a time span of 10 yr or longer, with at least two sampling events. We focused on studies that presented or allowed calculation of total community abundance or biomass. We extracted data from tables, figures, and appendices, and, for data sets that provided raw data, we standardized trapping effort over space and time when necessary. For each site, we extracted provenance details (such as country, state, and continent) as well as information on protection status, land use, and climatic details from publicly available GIS sources. In all, the database contains 1,668 plot-level time series sourced from 165 studies with samples collected between 1925 and 2018. Sixteen data sets provided here were previously unpublished. Studies were separated into those collected in the terrestrial realm (103 studies with a total of 1,053 plots) and those collected in the freshwater realm (62 studies with 615 plots). Most studies were from Europe (48%) and North America (29%), with 34% of the plots located in protected areas. The median monitoring time span was 19 yr, with 12 sampling years. The number of individuals was reported in 129 studies, the total biomass was reported in 13 studies, and both abundance and biomass were reported in 23 studies. This data set is published under a CC-BY license, requiring attribution of the data source. Please cite this paper if the data are used in publications, and respect the licenses of the original sources when using (part of) their data as detailed in Metadata S1: Table 1., (© 2021 Commonwealth of Australia. Ecology © 2021 Ecological Society of America.)

The first record of Menemerus fagei Berland & Millot 1941 (Araneae, Salticidae) from the Maltese Islands is reported and discussed. It is the 20th jumping spider species for Malta and a new record for Europe. [ABSTRACT FROM AUTHOR]

Background: Modern pest control management systems are based on the support of naturally occurring arthropod predators, as it has been shown that such predators offer an important ecosystem service. However, most naturally occurring arthropod predators are generalists (euryphagous). Their role in the biological control of specific pests has been recognized but remains poorly studied. Here, we focused on the naturally occurring arthropod predators of psyllids - the main insect pest of pear trees. We investigated the abundance of psyllids and all of their potential enemies in an abandoned pear orchard on a weekly basis from early spring to early summer. In addition, employing polymerase chain reaction diagnostics and specific primers, we investigated the predation rate on psyllids in all predators collected., Results: We found four predatory groups: spiders were the most abundant (60%, N = 756), followed by coccinellid beetles, anthocorid bugs and cantharid beetles. Anthocorids and spiders had the highest predation rates among the predatory groups. Among spiders, >50% of foliage-dwelling spiders (belonging to the genera Philodromus and Clubiona; N = 206) were positive for psyllids and showed a numerical response to the abundance of psyllids., Conclusion: We conclude that foliage-dwelling spiders are, of the four groups, the most important natural enemies of psyllids on pear trees during spring in Central Europe, as they outnumber specialized Anthocoris bugs. © 2021 Society of Chemical Industry., (© 2021 Society of Chemical Industry.)