Carabid Beetle Species Research Articles

Comparing the efficacy and cost-effectiveness of two sampling methods for monitoring carabid beetle diversity, species assemblages and conservation status in an alpine grassland

Comparing the efficacy and cost-effectiveness of two sampling methods for monitoring carabid beetle diversity, species assemblages and conservation status in an alpine grassland

Indirect effects of low-impact thinning on insect communities in forest floor of coniferous plantations

ABSTRACT To reveal the effects of low-impact thinning of coniferous planted forests on insects’ diversity, we investigated the relationship among cover degree and the number of plant species and the number of insect species in eight functional groups of herbivorous beetles, ants and carabid beetles at 63 sites of Japanese cedar and cypress which were thinned or unthinned and located in the middle of Japan. We found that when low thinning was applied to approximately 30% of the stand density, the number of plant species increased from the following year, and cover degree moderately increased in the years following thinning, although canopy openness did not significantly change. Using structural equation modeling, we found that the number of herbivorous beetle species increased with the cover degree increment of feeding-intended plants (woody-plants and herbs/vines) in the 4–8 years after thinning. The number of species of woody-plant feeding beetles also increased with an increase in the number of herb/vine plant species. For ant species, the number of habitat generalist species increased in the 4–8 years after thinning or with cover degree increment, although no response was observed in woodland specialist and open-habitat specialist species. For carabid beetle species, only the number of large-size species, not including open-habitat specialists, increased with cover degree increment. It was considered that there were moderate, and yet sustainable, positive effects of low-impact thinning on species diversity of forest-floor-inhabiting insects via understory vegetation increment with a lag-time, and no promotion of migration of non-forest-habitat ant and carabid beetle species.

Host and environmental influences on the gut bacterial community of carabid beetles in distinct paddy fields

AbstractThe relationship between the gut bacterial communities of carabid beetles and their habitats holds implications for understanding ecological dynamics. This study examined the gut bacterial communities of two carabid beetle species, Chlaenius pallipes and Pheropsophus jessoensis, in terraced and flat paddy fields. Differences in gut bacterial communities were evident at the species level and were based on habitat. Specifically, P. jessoensis had a greater presence of Firmicutes and Proteobacteria in terraced fields but more Actinobacteria in flatland fields. In comparison, C. pallipes consistently showed high levels of Firmicutes in both habitats. These differences were reflected at class and genus levels, emphasizing the role of host specificity in shaping gut microbiota. Alpha diversity metrics indicated that P. jessoensis hosted a more diverse bacterial community than C. pallipes. Terraced fields, however, showed slightly reduced diversity in P. jessoensis, suggesting environmental effects on microbial populations. Beta diversity analysis using Bray–Curtis distances differentiated the bacterial communities of the two beetles. Multivariate analysis of variance reinforced these findings. Insights from the Sloan neutral model indicate that environmental factors predominantly influence bacterial community assembly through stochastic processes. Functionally, metabolism was highlighted, indicating the role of gut bacteria in beetle metabolic processes. Notably, energy metabolism varied between field types, revealing environmental effects on gut bacterial functions. This study offers in‐depth insights into interactions between host‐specific and environmental factors influencing gut bacterial communities of carabid beetles, contributing to a broader understanding of microbial ecology and the roles of environment and host in microbiota dynamics.

Predicting movement speed of beetles from body size and temperature

Movement facilitates and alters species interactions, the resulting food web structures, species distribution patterns, community structures and survival of populations and communities. In the light of global change, it is crucial to gain a general understanding of how movement depends on traits and environmental conditions. Although insects and notably Coleoptera represent the largest and a functionally important taxonomic group, we still know little about their general movement capacities and how they respond to warming. Here, we measured the exploratory speed of 125 individuals of eight carabid beetle species across different temperatures and body masses using automated image-based tracking. The resulting data revealed a power-law scaling relationship of average movement speed with body mass. By additionally fitting a thermal performance curve to the data, we accounted for the unimodal temperature response of movement speed. Thereby, we yielded a general allometric and thermodynamic equation to predict exploratory speed from temperature and body mass. This equation predicting temperature-dependent movement speed can be incorporated into modeling approaches to predict trophic interactions or spatial movement patterns. Overall, these findings will help improve our understanding of how temperature effects on movement cascade from small to large spatial scales as well as from individual to population fitness and survival across communities.

Species Enriched Grass–Clover Pastures Show Distinct Carabid Assemblages and Enhance Endangered Species of Carabid Beetles (Coleoptera: Carabidae) Compared to Continuous Maize

There is an urgent global need for the ecological intensification of agricultural systems to reduce negative impacts on the environment while meeting the rising demand for agricultural products. Enriching grasslands with floral species is a tool to promote diversity and the associated services at higher trophic levels, and ultimately, to enhance the agricultural landscape matrix. Here, we studied an organic pastures-based dairy production system with plant species enhanced grass–clover pastures with respect to the effect on the activity density, functional traits, carabid assemblages, and species richness of carabid beetles. To understand the effect of land management on carabid beetles, we studied two types of grass–clover pastures with low and relatively high plant diversities in an integrated crop–livestock rotational grazing system (ICLS). As a comparison, organic permanent grasslands and conventionally managed maize were studied. We installed pitfall traps for three weeks in early summer, and for two weeks in autumn. In total, 11,347 carabid beetles of 66 species were caught. Grass–clover pastures did not differ in activity density, functional traits, habitat guilds, or species richness, but conventional maize did show a higher activity density in autumn and a higher proportion of eurytopic species and mobile species compared to grass–clover pastures. On grass–clover pastures, we found more endangered species, Carabus beetles, and a distinct carabid assemblage compared to maize. However, we attribute the lack of an effect of increased plant diversity of the grass–clover pastures on carabid species richness and functional traits to the intensive grazing regime, which resulted in the compositional and structural homogeneity of vegetation. Still, the presence of specialized and endangered species indicated the potential for organically managed grass–clover pastures to promote dispersal through an otherwise depleted and fragmented agricultural landscape. By increasing crop diversity in ICLS, more resources for foraging and nesting are created; therefore, organically managed grass–clover pastures add to the multi-functionality of agricultural landscapes.

The flower strip dilemma (FSD): An overlooked challenge in nature conservation and a possible first step towards a solution by combining different aged flower strips

Perennial flower strips on high-yield soils may lose most of their flowering aspect during aging. This creates a dilemma, referred to herein as flower strip dilemma (FSD): On the one hand the number of pollinating and non-pollinating insects increases during the short-term aging of flower strips, on the other hand, perennial flower strips of a certain age often become grass dominated and are therefore less attractive to many species. Thus, the question arises when there is the most appropriate time to create a new flowering strip to support as many species as possible. To find a way out of the described dilemma, we focused on carabid beetles in two different aged types of flower strips. Many ground beetle species (carabids) are important pest antagonists in intensively cultivated farmland and can be promoted by flower strips. The creation of combined wildflower strips, consisting of wildflower strips of different ages, might be a measure to compensate the loss of species richness and abundance during flower strip aging. To study the impact of combined wildflower strips on non-pollinating insects, we recorded carabid beetles as a model guild in one- and three-year-old wildflower strips as well as in combined wildflower strips, and examined the results regarding species richness, abundance and functional traits. We show that combined wildflower strips increase the richness of carabid beetle species significantly beyond simple aging effects. Furthermore, the dominating functional traits of carabids differ with the type of flower strip: In combined wildflower strips significantly more macropteric and herbivorous carabid species were found, as well as carabids with imaginal hibernation. The study shows that the creation of combined wildflower strips can increase species richness in carabids by buffering possible negative effects in either young or old flower strips regarding their specific attractiveness for different species or guilds respectively. As a recommendation, farmers should create at least part of their flower strips in combination, so that a greater effect on increasing biodiversity can be achieved. Further investigations should make suggestions for how long a flower strip should exist according to different taxa to make the problem of the FSD more visible.

Application of unsupervised machine learning techniques to assessment of quality habitat

As a result of human activities, river valleys have changed: river beds have been transformed as a result of their regulation and dam construction. This paper presents unsupervised machine learning techniques to distinguish arthropod communities and attempts to explain the ecological priorities of individual species based on them. Data on a group of 95 species of carabid beetles from 16 habitats on the floodplains of two rivers - Bytytsia and Strilka (Dnipro basin, Ukraine). Analyses were performed using the program R version 4.1.1. Fuzzy clustering was performed using the fanny function from the R cluster package, and visualization of the results was performed using the t-SNE method from the Rtsne package. In our analysis, the following habitat type characteristics were chosen to distinguish communities: closed (forest) or open (grassland). According to the results of fuzzy clustering, out of 95 carabid species, 37 species were selected whose probability of belonging to their cluster was at least 0.95. These species form distinct three groups. The first group of carabid species is associated with forest sites in Bytytsia. The second group is connected with occurrence on meadow sites in Strilka. The third group of species is connected mainly with the meadow sites of the Bytytsia River. Established groups of species reflect the current ecological situation on floodplains and the influence of human activities on it.

한려해상국립공원 내 지표성 딱정벌레류(딱정벌레목: 딱정벌레과)군집의 다양성과 계절적 변화

This study was conducted to investigate diversity and its seasonal change of carabid beetles in the Hallyeohaesang national park, especially in forest environments. A total of 15 sites were selected. As islands, 5 sites in Namhaedo, 4 sties in Tongyeong, 3 sites in Geojedo, 1 site in Odongdo and Neukdo were selected and 1 site in Mt. Geumo in Hadong-gun was selected as mainland. Sampling was conducted by pitfall traps from June to October in 2014. A total of 1,072 individuals belonging to 25 carabid beetle species were collected. In most islands, Synuchus nitidus was dominant, but subdominant species was different depending on islands. In number of species, 15 carabid beetle species were collected in Namhaedo that was the highest following by Tongyong (14 species), Neukdo (10 species), Geojedo (9 species), Mt. Geumo (mainland, 6 species), and Odongdo (4 species). Number of species and abundance were generally increased from early summer to autumn. In consequence, we added 12 carabid beetle species to the insect fauna of Hallyeohaesang national park, and it is expected that more insect species can be found considering by environmental characteristics and seasonality of islands.

The Gut Bacterial Community of Chlaenius pallipes (Coleoptera: Carabidae) Associates with Their Habitat and Morphology.

We investigated whether the gut bacterial community of Chlaenius pallipes could represent the health conditions of individuals or populations based on where these beetles inhabit. Considering the ecological traits of the species, the gut bacterial communities of carabid populations inhabiting stable or unstable habitats were compared. Food resource quality (δ15N) and morphological shape, especially body and wing size, may be significant factors that directly or indirectly affect the gut bacterial community of carabid beetles. Firmicutes (51.7%) and Proteobacteria (36.3%) were the predominant phyla in the gut bacterial community of C. pallipes. A significant difference in the gut bacterial community structure was observed between organisms inhabiting unstable and stable habitats in this study. Wing size, as estimated by centroid size, was correlated with differences in the gut bacterial community composition of the species. Even if a factor is not strong enough to determine the survival of carabid beetles, the composition of the gut bacterial community can change. We found that although each individual has a large variation in the gut bacterial community composition, the gut bacterial community can be used to evaluate the condition of each habitat through consistent investigation. Habitat assessment based on changes in the number of carabid beetle species and their composition requires relatively long-term research; however, the gut bacterial community of carabid beetles can help identify short-term environmental changes.

The types of some West Palearctic taxa of Zabrini, Platynini and Sphodrini (Coleoptera: Carabidae) described by Dejean

Summary Data on the designation of a number of type specimens of Dejean's collection deposited in the Museum national d’Histoire naturelle, in Paris, are given. Types correspond to species of carabid beetles belonging to tribes Zabrini, Platynini and Sphodrini, that are found in the West Palearctic region. The holotype of the following taxa was recognized: Amara tricuspidata Dejean, 1828, Zabrus marginicollis Dejean, 1828, Zabrus pinguis Dejean, 1831, Anchomenus cyaneus Dejean, 1828, Agonum thoreyi Dejean, 1828 and Anchomenus melanocephalus Dejean, 1828. The lectotype of the following taxa was designated: Amara rufipes Dejean, 1828, Zabrus gravis Dejean, 1828, Zabrus silphoides Dejean, 1828, Zabrus graecus Dejean, 1828, Olisthopus punctulatus Dejean, 1828, Olisthopus hispanicus Dejean, 1828 and Calathus rotundicollis Dejean, 1828. Notes on type story, present status of the taxon, references to keys to identify it and data on present geographic distribution are indicated for each species.

Conservation value of traditional meadow irrigation for carabid beetles

Locally adapted and evidence-based management strategies are needed to counteract the current insect declines. In Central Europe, semi-natural grasslands are biodiversity hotspots having a high conservation value, but are threatened by both abandonment and agricultural intensification. We investigated the potential of traditional lowland meadow irrigation as a biodiversity-friendly grassland management strategy using carabid beetles as indicator organisms. We analysed carabid beetle species richness, the occurrence of species of conservation concern, and trait composition in relation to meadow irrigation and fertilization. Moreover, we conducted bipartite network analysis in order to reveal species-habitat networks. The key finding is that the species richness of carabid beetles in irrigated and non-irrigated meadows was similar, but irrigation positively influenced species and individual numbers of carabids of conservation concern. Meadow irrigation, but also fertilization, further shaped carabid beetle species-habitat-networks indicating species-specific preferences for differently managed meadows. Finally, the trait composition was affected: carabid beetles in irrigated meadows were on average larger, more predacious and less mobile than in non-irrigated meadows. We therefore recommend the preservation and restoration of this traditional grassland management practice for biodiversity conservation in suitable regions, but also call for future studies to further increase conservation evidence.

Legacy of landscape crop diversity enhances carabid beetle species richness and promotes granivores

It is well understood that agricultural expansion and associated loss of semi-natural habitat in the landscape are major drivers for the marked decline in biodiversity. While conserving remaining semi-natural habitat patches is essential to reverse ongoing biodiversity declines, increasing focus has also been put on diversifying cropland itself by increasing landscape crop diversity as a measure of compositional heterogeneity, and reducing field sizes as a measure of configurational heterogeneity. Both these cropland diversification approaches have shown promise to enhance biodiversity in the year of sampling, but it is unknown whether legacies of crop diversity in the landscape promote biodiversity by building up arthropod communities over time. We selected 14 faba bean fields in landscapes dominated by cropland. The fields were chosen along three gradients: landscape crop diversity of the year of sampling (2017), landscape crop diversity of the previous year (2016) and mean field size in landscapes. Using pitfall traps, we show that the carabid beetle species richness is higher in landscapes with higher crop diversity in the previous year. Especially, granivorous carabid beetles benefitted from legacies of crop diversity. Rove beetles were more abundant and genus rich in landscapes with larger field sizes, while spiders were not responding to any of the landscape variables. A diversity of crops in the landscape and their associated weed communities could provide more diverse food resources and shelter habitats, which build populations of carabid beetle species over time. There is a need to explore the effects of agri-environmental schemes across multiple years to better understand legacy effects, and to structure sustainable agricultural landscapes.

Decrease in Carabid Beetles in Grasslands of Northwestern China: Further Evidence of Insect Biodiversity Loss.

Simple SummaryLong-term studies on insect diversity trends are rare, especially in steppe ecosystems. To gain insights into carabid beetle diversity trends in steppe grasslands, we analyzed data on carabids from a trapping study that ran for 12 years in the grasslands of northwestern China. We found that species abundance and richness declined over time. The results of this study suggest that precipitation may play a role in changing species dynamics. This study emphasizes the urgent need to protect carabid communities in steppe ecosystems.Ground-dwelling beetles are important functional components in nutrient-poor grasslands of middle temperate steppe ecosystems in China. Here, we assessed the changes in ground beetle (Coleoptera: Carabidae) communities in the grasslands of northwestern China over 12 years to improve the management and conservation of beetles all over the world. The Generalized Additive Model (GAM) was applied to estimate the changes in carabid beetle communities in two regions: a desert steppe (Yanchi region), and a typical steppe and meadow steppe (Guyuan region). During the 12-year investigation, a total of 34 species were captured. We found that species abundance and richness per survey declined by 0.2 and 11.2%, respectively. Precipitation was the main factor affecting the distribution of carabid beetles. A distinct decline in carabid beetle species in the Yanchi region indicated that they may be threatened by less precipitation and loss of habitat, which could be due to climate change. Overall, species richness was stable in the Guyuan region. It is necessary to estimate and monitor the changes in carabid beetle communities in a temperate steppe of northern China and to protect them. Extensive desertification seriously threatens the distribution of carabid beetles. Future research should develop methods to protect carabid beetle communities in temperate steppes in China.

Rejuvenation and restoration measures foster specialised and threatened carabid beetle species in montane heathland ecosystems

Abstract Montane heathlands are among the most threatened semi‐natural ecosystems across Central Europe. Nevertheless, empirical studies on the effects of rejuvenation and restoration of montane heathlands have been scarce thus far. The aim of our study was to analyse the long‐term effects of heathland rejuvenation and restoration on carabid beetle assemblages. Our study took place in the Rothaar Mountains, one of the most important strongholds of montane heathlands in Central Europe. We considered four different successional stages: (i) early‐successional heathlands as a result of rejuvenation measures (EARLY), (ii) restored heathlands (RESTORED), (iii) late‐successional heathlands (LATE) and (iv) windthrows (WIND). Our study revealed that the composition of carabid beetle assemblages differed across the gradient. From the earlier to the later stages, beetle biomass, richness of macropterous, threatened and heathland species decreased, whereas moisture and shading indicator values increased. The number of indicator species peaked in EARLY and RESTORED. Solely brachypterous species had the highest species richness in the later seral stages. Overall, rejuvenation and restoration measures fostered specialised and threatened carabid beetle species of montane heathlands. In contrast, carabid beetle assemblages of the two later and dense successional stages consisted mainly of non‐threatened habitat generalists. Vegetation structure and the interrelated microclimate are assumed to be the key drivers of assemblage composition. For the long‐term conservation of montane heathlands and their specialised carabid beetle assemblages, we recommend rejuvenation by sod cutting and choppering in a mosaic‐like manner and at intervals that clearly exceed more than two decades.

The biology of seed discrimination and its role in shaping the foraging ecology of carabids: A review.

Species of carabid (ground) beetles are among the most important postdispersal weed seed predators in temperate arable lands. Field studies have shown that carabid beetles can remove upwards of 65%–90% of specific weed seeds shed in arable fields each year. Such data do not explain how and why carabid predators go after weed seeds, however. It remains to be proven that weed seed predation by carabids is a genuine ecological interaction driven by certain ecological factors or functional traits that determine interaction strength and power predation dynamics, bringing about therefore a natural regulation of weed populations. Along these lines, this review ties together the lines of evidence around weed seed predation by carabid predators. Chemoperception rather than vision seems to be the primary sensory mechanism guiding seed detection and seed selection decisions in carabid weed seed predators. Selection of weed seeds by carabid seed predators appears directed rather than random. Yet, the nature of the chemical cues mediating detection of different seed species and identification of the suitable seed type among them remains unknown. Selection of certain types of weed seeds cannot be predicted based on seed chemistry per se in all cases, however. Rather, seed selection decisions are ruled by sophisticated behavioral mechanisms comprising the assessment of both chemical and physical characteristics of the seed. The ultimate selection of certain weed seed types is determined by how the chemical and physical properties of the seed match with the functional traits of the predator in terms of seed handling ability. Seed density, in addition to chemical and physical seed traits, is also an important factor that is likely to shape seed selection decisions in carabid weed seed predators. Carabid responses to seed density are rather complex as they are influenced not only by seed numbers but also by trait‐based suitability ranks of the different seed types available in the environment.

The response of plants, carabid beetles and birds to 30 years of native reforestation in the Scottish Highlands

Abstract Globally, there is increasing interest in tree planting, leading to many country‐level commitments to reforestation. In the UK, current commitments would achieve 17% forest cover by 2050, with the highest rates of forest expansion expected in Scotland. Forest expansion with native trees is expected to increase biodiversity, particularly woodland specialist species, and associated ecosystem services. Despite this, data on biodiversity changes over the early stages of reforestation are sparse, particularly for upland areas in Scotland where opportunities for forest expansion are greatest. We collected data on the response of plants, carabid beetles and birds to native reforestation and grazing exclusion, using sites reforested over the last 30 years in the Scottish Highlands. Biodiversity in ungrazed, reforested sites was compared to unforested controls and mature native forest, both grazed and ungrazed. Mean bird species richness in reforested plots (4.4 [95% CI: 3.2, 5.9]) was higher than in unforested plots (0.8 [0.5, 1.3]), but lower than in mature forest plots (7.0 [5.4, 8.3]). In contrast, there was no systematic difference in plant or carabid beetle species richness in reforested, unforested or mature forest plots, or between grazed and ungrazed plots for the species richness of any groups. Woodland specialist bird and plant species were found in the reforested plots, and richness of woodland specialist bird species was predicted to reach levels in mature forest c. 36 years after reforestation. Species assemblages differed across habitat categories. For birds and plants, species assemblages in reforested sites were intermediate to unforested and mature sites. For carabid beetles, the assemblages in mature and reforested sites were comparable and differed from unforested sites. Grazing did not strongly influence species assemblages. Policy implications. We show that woodland specialists colonise reforested sites and species assemblages transition towards those found in the target habitat within the first 30 years of reforestation with native species. Native forest should be prioritised in Scotland's future forest expansion targets, given that mature native forest is scarce and fragmented in the Scottish Highlands and that the ultimate gain from native forest expansion may accrue over long time‐scales.

Yalongaphaenops erwini gen. et sp. nov., the world's most high-altitude hypogean trechine beetle from China (Coleoptera, Carabidae, Trechinae).

A new genus and new species of carabid beetle, Yalongaphaenops erwinigen. et sp. nov., is described from mountains SW of Mianning City, Sichuan Province, China. This finding, from one side, extends the known distribution of Chinese hypogean trechines, and from another, it raises the upper limit of their vertical distribution to nearly 4000 m. Photographs of the habitus and major taxonomic characters, including the male genitalia, right mandible, and microsculpture patterns of the integument are supplied. The type locality of the new taxon is mapped. Yalongaphaenopsgen. nov. shows some similarities with the genus Shiqianaphaenops Tian, 2016 from eastern Guizhou and the genus Boreaphaenops Uéno, 2002 described from Hubei, China. However, the direct relationships of the new genus remain unclear. Further new discoveries of hypogean trechines in Sichuan are necessary to evaluate possible variation of major characters in allied taxa. Although Y. erwinisp. nov. was collected at an elevation exceeding 3800 m a.s.l., it conforms to the upper limit of the forest zone being approximately on par with the vertical distribution of some high altitude hypogean trechine species in other parts of the globe.

Early successional dynamics of ground beetles (Coleoptera, Carabidae) in the tropical dry forest ecosystem in Colombia.

Little is known about the successional dynamics of insects in the highly threatened tropical dry forest (TDF) ecosystem. For the first time, we studied the response of carabid beetles to vegetal succession and seasonality in this ecosystem in Colombia. Carabid beetles were collected from three TDF habitat types in two regions in Colombia: initial successional state (pasture), early succession, and intermediate succession (forest). The surveys were performed monthly for 13 months in one of the regions (Armero) and during two months, one in the dry and one in the wet season, in the other region (Cambao). A set of environmental variables were recorded per month at each site. Twenty-four carabid beetle species were collected during the study. Calosoma alternans and Megacephala affinis were the most abundant species, while most species were of low abundance. Forest and pasture beetle assemblages were distinct, while the early succession assemblage overlapped with these assemblages. Canopy cover, litter depth, and soil and air temperatures were important in structuring the assemblages. Even though seasonality did not affect the carabid beetle assemblage, individual species responded positively to the wet season. It is shown that early successional areas in TDF could potentially act as habitat corridors for species to recolonize forest areas, since these successional areas host a number of species that inhabit forests and pastures. Climatic variation, like the El Niño episode during this study, appears to affect the carabid beetle assemblage negatively, exasperating concerns of this already threatened tropical ecosystem.

Benefits of wildflower areas as overwintering habitats for ground-dwelling arthropods depend on landscape structural complexity

Wildflower areas are a popular agri-environment scheme to counteract the biodiversity loss in agro-ecosystems. While benefits for flower-visiting and predatory insects during the vegetation period were frequently shown, few studies addressed the suitability of wildflower areas as overwintering habitats. Here, we studied the significance of wildflower areas as overwintering habitats and whether their benefits vary with landscape context, i.e. the proportions of permanent semi-natural habitats such as hedges. We selected ten landscapes that encompassed independent gradients of proportions of permanent semi-natural habitats (e.g. hedgerows, ditches) and transient wildflower areas. The centres of the landscapes were pairs of wildflower areas and arable fields on which we sampled overwintering ground-dwelling arthropods by emergence traps. In total, we recorded 2838 overwintering individuals from 115 species of rove and carabid beetles as well as spiders. Abundance of rove beetle larvae, as well as species richness of adult rove beetles and spiders was significantly higher in wildflower areas than in arable fields. With respect to landscape context, abundance and species richness of adult rove beetles showed a hump-shaped relationship with the proportion of permanent semi-natural habitats. The abundance of adult carabid beetles showed a hump-shaped relationship with the proportion of transient wildflower areas, while the abundance of carabid beetle larvae showed a hump-shaped pattern with permanent semi-natural habitats. For the first time we showed that, similar to the vegetation period, benefits of wildflower areas as overwintering habitats for ground-dwelling arthropods depend on both local habitat characteristics as well as landscape context. Benefits of wildflower areas for overwintering were highest in simple landscapes with an intermediate proportion of either permanent semi-natural habitats or transient wildflower areas. Our results suggest that in order to sustainably maintain the functional guild of ground-dwelling arthropods, agricultural landscapes should provide both sown wildflower areas and permanent semi-natural habitats. Our results also support the general claim that semi-natural habitats should at least contribute 10–15% to agricultural landscapes in order to maintain the characteristic biodiversity in modern agro-ecosystems.

Deadwood, Soil and Carabid Beetle-Based Interaction Networks—An Initial Case Study from Montane Coniferous Forests in Poland

In four study plots located in silver fir and Scots pine stands in Magura National Park (southeastern Poland), the relationships between the occurrence and biomass of epigeic carabids, the volume of deadwood and soil biochemical properties were investigated. Thirteen carabid beetle species from the genera Abax, Carabus, Molops and Pterostichus were captured. Rare epigeic carabid species in the fauna of Poland and Europe, such as Carabus glabratus (Paykull), Carabus sylvestris (Panzer) and Abax schueppeli (Germar), were recorded. The number of carabid individuals and species captured as well as the mean individual biomass index at different elevations and in forests of different tree compositions differed significantly. There were no correlations between deadwood volume, carabid abundance and the mean individual biomass of the carabid beetles. The mean individual Carabidae biomass increased with elevated pH, soil carbon content, soil dehydrogenase activity and the number of stumps.