Carabid Beetles Research Articles

Comparison of alien Robinia pseudoacacia stands with native forest stands across different taxonomic groups

There is much knowledge about the impact of non-native Robinia pseudoacacia on native ecosystems, but mostly it is related to one group of organisms. In this article, we provide an analysis of the impact of R. pseudoacacia on the surrounding biota with a broader scope in a model area with homogeneous abiotic conditions compared and analysed by the twin plots method. Microclimatic conditions and the changes in the species composition of vegetation, terrestrial gastropods, carabid beetles, bats, and acoustic diversity were analysed. The planted Robinia stands were always brighter and warmer and had lower canopy closure than the control plots in the native floodplain forest. More nitrogen and phosphorus were recorded in the soil of the Robinia stands. The floristic composition changed the most based on the planting of Robinia trees. Compared to those in the adjacent floodplain forest, more heliophilous neophytes, archaeophytes and grasses were found. Assemblages of gastropods and carabid beetles were less affected by the planting of Robinia trees and more by the microclimatic conditions of the studied locality. The number of recorded bats and acoustic diversity were higher in native floodplain forests due to food and shelter options.All results show that the planting of Robinia trees changes the microclimatic conditions and species composition of forest stands. The warmer and less humid environment under Robinia stands is not desirable in the face of ongoing climate change. The alien (including invasive) and ruderal plant species in the understorey are supported due to the more favourable brighter conditions and nitrogen fixation in the soil. Additionally, the other groups of organisms react negatively to changes under Robinia trees in terms of microclimatic conditions, food and shelter sources. Therefore, forest managers, policy-makers and conservation workers should choose stratified management when deciding whether and where to plant R. pseudoacacia.

Epigeic Carabids (Coleoptera, Carabidae) as Bioindicators in Different Variants of Scots Pine Regeneration: Implication for Forest Landscape Management

Maintaining biodiversity is one of the factors determining the proper functioning of ecosystems, especially those with high human impact. Ground beetles, as bioindicators, are particularly valuable in understanding ecosystem responses and sustainability in forest and landscape management. Focusing on the regeneration of pine forests, this study aimed to describe ground beetle assemblages on Scots pine natural and artificial regeneration in northeastern Poland. This study was conducted between 2016 and 2018. Pitfall traps were set up for catching epigeic carabids on previously prepared research plots designated for natural and artificial pine regeneration. The research areas included three variants: N—natural pine regeneration, plots without soil preparation; NP—natural pine regeneration with traditional soil preparation by ploughing; and A—artificial pine regeneration with ploughing. Four plots as replicants were selected in each experimental variant, with six pitfall traps in the transects running through the centre of each study plot. In each year of the study, 11 samples were collected from each plot; overall, 33 samples per plot were collected during the three years. As a result of this study, 26,654 ground beetle individuals belonging to 89 species were caught during the three-year observation. Natural regeneration without soil preparation (N) was the most favourable in terms of the occurrence of stabilised assemblages of ground beetles. However, the remaining methods of pine regeneration, on a multi-annual scale (2016–2018), contributed to the increase in the number of ground beetles but also provided high variability in assemblage composition, diversity indices, and life-history traits. Thus, in the early stage of pine regeneration, each of the examined variants of pine regeneration can be used without fear of causing damage to carabid populations. However, further studies are required to investigate the effect of different pine regeneration types on carabid beetle assemblages over a longer period.

Modelling weed seed predation by carabids and its effects on crop production under contrasted farming systems

To reduce herbicide use, different avenues of biological weed regulation are currently investigated. Among these, weed seed predation by carabid beetles appears promising. Though observed in different cropping systems and conditions in fields, there was to date no demonstration that this process actually influences weed dynamics over time and reduces weed harmfulness for crop production. Consequently, the objective of the present paper was to (1) model the impact of cropping system, field margin and pedoclimate on weed seed predation by carabids to complete the FlorSys model, which simulates weed dynamics and crop production from cropping systems, soil and weather, (2) evaluate whether including seed predation is needed to correctly predict weed dynamics in different cropping systems, (3) which components of the seed predation submodel are the most influential. The new seed-predation submodel calculates the daily predation rate for each weed species from seed traits, weather data, canopy state variables and management operations. In FlorSys, this predation rate is applied to the newly shed weed seeds on the soil surface. The equations and parameters were based on past publications from our team and other literature. Then, simulations were run with FlorSys over 13 years, with and without the seed predation submodel, using weather data and management operations from 10 fields from the INRAE Dijon-Epoisses experimental station. The resulting output in terms of weed and crop state variables (plant density, biomass, seed bank, yield) were compared to measurements from the 10 fields, showing that including weed seed predation in the simulations improved the model's prediction quality, by reducing the overestimation in weed-variable predictions. Finally, a sensitivity analysis to the components of the predation submodel was run, by repeating the simulations after successively switching off individual components of the submodel. This showed that daily incident radiation, light interception by plant canopy, harvest, carabid reproduction and daily temperature had the most influence on seed predation rates. The simulations showed that weed seed predation by carabids can indeed contribute to managing weeds, by reducing field infestation and improving crop yields, but with large variations among crops. However, to determine which cropping systems and field margins favour weed seed predation enough to noticeably contribute to biological weed regulation, a larger diversity of cropping systems and weather series needs to be explored by simulation.

Potential of a linear woodland landscape element as ecological corridor for carabid beetles (Coleoptera: Carabidae): a case study from Poland

Fragmentation of landscapes and habitats has been identified as the main driver of biodiversity loss. Ecological corridors may support the conservation of biota in fragmented landscapes due to enhanced habitat connectivity. We conducted a study in order to assess the potential of a linear woodland landscape element along a railway line as ecological corridor using carabid beetles as indicators. The results showed that for some forest species the studied woodland strip has potential as an ecological corridor. Trophy and soil acidity were most often significantly correlated with parameters and species, but width of the woodland strip and distance from the forest site were of highest importance for the formation of the whole carabid assemblages. The results of our study provide with information regarding rules for the construction of woodland strips as ecological corridors. Management strategies should integrate such areas in concepts of sustainable regional development.

Functional trait composition of carabid beetle communities predicts prey suppression through both mass ratio and niche complementarity mechanisms.

Several components of predator functional diversity have been hypothesized to influence prey suppression through either niche complementarity or mass ratio effects. Nevertheless, most studies have used a functional group approach when assessing the role of these predators in ecosystem functioning. By adopting a trait-based approach, we evaluated the relative contributions of carabid diversity components in predicting prey suppression. Our results highlight the importance of both taxonomic and functional diversity components of carabids as key drivers of prey suppression. Prey suppression was best predicted by carabid densities, with the dominance of Poecilus cupreus potentially driving the positive effect of community total abundance through the mass ratio effect. Prey suppression increased with increasing the density of large carabids. In addition, carabid eye diameter and antennal length were key functional traits for predicting prey suppression. Furthermore, prey suppression increased with increasing carabid functional richness following the niche complementarity effect. In contrast to functional richness, functional evenness and functional divergence of carabid communities were weakly correlated with prey suppression. By identifying which diversity components of carabid communities contribute the most to increase prey suppression, our results can guide efforts aiming to predict the relationship between diversity of these predators and ecosystem functioning.

Urbanisation generates multiple trait syndromes for terrestrial animal taxa worldwide

Cities can host significant biological diversity. Yet, urbanisation leads to the loss of habitats, species, and functional groups. Understanding how multiple taxa respond to urbanisation globally is essential to promote and conserve biodiversity in cities. Using a dataset encompassing six terrestrial faunal taxa (amphibians, bats, bees, birds, carabid beetles and reptiles) across 379 cities on 6 continents, we show that urbanisation produces taxon-specific changes in trait composition, with traits related to reproductive strategy showing the strongest response. Our findings suggest that urbanisation results in four trait syndromes (mobile generalists, site specialists, central place foragers, and mobile specialists), with resources associated with reproduction and diet likely driving patterns in traits associated with mobility and body size. Functional diversity measures showed varied responses, leading to shifts in trait space likely driven by critical resource distribution and abundance, and taxon-specific trait syndromes. Maximising opportunities to support taxa with different urban trait syndromes should be pivotal in conservation and management programmes within and among cities. This will reduce the likelihood of biotic homogenisation and helps ensure that urban environments have the capacity to respond to future challenges. These actions are critical to reframe the role of cities in global biodiversity loss.

High mortality of beetle migrants along the Eastern Mediterranean Flyway

Abstract Migration is costly in terms of increased energy expenditure and exposure to risks encountered en route. These factors can lead to a higher mortality among migrants compared with more sedentary life history stages. Insect migrants are incredibly numerous, but as they are less conspicuous than vertebrate migrants and as migration often occurs at high altitude and over a broad front, it can be difficult to study migration‐related mortality. A major source of information on migration‐related mortality comes from cadavers found on the strandline following unsuccessful sea crossings. Here, we analyse strandline mortality following a 100 km crossing of open ocean along the Eastern Mediterranean Flyway from the Middle East mainland to the island of Cyprus by tens of millions of insects. All strandline recordings were of two species of beetles, the seven‐spot ladybird Coccinella septempunctata and the carabid beetle Calosoma olivieri, whereas only nine individuals of C. septempunctata were caught successfully arriving with the rest of the insect assemblage over the ocean. Major strandings were associated with easterly winds, suggesting origins from the Middle East mainland, with the individuals documented as extremely weak and unable to fly or dead. Our results suggest that beetles are weaker migrants than other members of the migratory insect assemblage, with the sea crossing too far for the great majority to fly, leading to high mortality. The impact of this high mortality on the marine ecosystems is discussed.

Sex-specific foraging response to interspecific interactions in carabid beetles

Carabids beetles are considered important biocontrol agents of weeds, but predicting levels of weed seed consumption and regulation is difficult. Olfactory cues from predators or potential competitors alter the selection and consumption of particular food resources by foraging individuals. Whether this leads to changes in consumption levels or simply to changes in the rate at which consumption takes place over time is not yet known. Identifying and understanding the factors that drive the seed foraging behaviour of carabid beetles, in the context of interspecific interaction, is essential for predicting consumption levels in different carabid communities and hence improve the ecosystem service of weed regulation by carabid beetles.We tested the response of 119 Harpalus affinis individuals foraging for Viola arvensis or Taraxacum officinale seeds, to encounters with individuals of another carabid species, Pterostichus melanarius. Their foraging behaviour (i.e. total consumption, latency to first seed acceptance and position in the arena) was recorded for 72 h and the consumption rates were reported in detail for the first 7 h of the experiment for all treatments.Even though the total number of seeds consumed after 24 h did not differ, the dynamic of seed consumption by H. affinis changed significantly in the presence of P. melanarius. The attraction of individuals to the seeds diminished over time, indicating a probable state of satiety being reached. This suggests that looking at the total number of seeds consumed after a long period of time may be misleading and that a greater focus on of the temporal dynamics of consumption is needed if we are to understand carabids interest in specific weed species in a specific foraging context. We found that only females seemed to react to the presence of P. melanarius individuals, indicating that the perception of the level of risk may be sex-specific in carabid beetles.

Assessing ground predation by invertebrates in crops: Camera observations clarify the relevance of aphid cards and coleopteran sentinel prey

Redesigning cropping systems to promote natural pest control requires a sound understanding of the regulation potential of natural enemies. Sentinel preys are useful to quantify biological control, but the use of aphid cards (aphids glued to a sandpaper card) is controversial for their lack of realism. The objectives here were: (1) to compare aphid cards to non-fixed beetle larvae resembling coleopteran pests, with respect to the consumers attracted; and (2) to ascertain whether predation on coleopteran prey larvae responds to different invertebrates communities.We used cameras to identify the consumers of two types of sentinel prey on the ground, and compared aphid cards to an original sentinel prey, bruchid beetle larvae. Aphids glued to predation cards attracted opportunistic consumers and scavengers with very long handling times, and even scavengers, including harvestmen (33% of consumption events), spiders and slugs, and a very few carabid beetles. Unattached bruchid beetle larvae were consumed largely by carabids (64%), and secondarily by rove beetles, ants and chilopods. As the sentinel prey were not consumed by the same organisms, these findings demonstrate the importance of the choice of organisms exposed to estimate pest predation.Knowing the identity of the bruchid larvae consumers from the images, we investigated whether the assemblages of epigeic arthropods could explain their predation rates under contrasting field conditions. Accounting for all the expected consumers, sentinel prey disappearance rates could be explained statistically with a satisfactory goodness-of-fit. Slugs and ants contributed more strongly to the disappearance of sentinel prey than carnivorous carabids and chilopods. Finally, alternative prey (especially Collembola) reduced consumption by diverting consumers from their usual prey. Camera observations were valuable to assess the relevance of two different sentinel preys and of the consumers involved. With this knowledge, it is possible to estimate the pest control potential from the ground-dwelling communities present.

Prey handling and feeding habits of the snail predator Licinus depressus (Coleoptera, Carabidae)

Carabid beetles of the tribe Licinini use their asymmetric mandibles to open the shells of land snails. Prey handling of large snails has been described in a few Licinini species. We observed for the first time how a male of Licinus depressus (Paykull, 1790) opens the shells of small prey snails (Chondrina arcadica (Reinhardt, 1881)) and eats their soft bodies. The beetle holds the conical snail shell with its forelegs and breaks the wall of the right-hand coiled shell. In doing so, the beetle rotates the shell counter-clockwise opening it stepwise along the dorsal part of the whorls towards the apex. After some bites, the beetle interrupts the opening process and begins to feed on the snail’s soft tissue. Then the beetle continues to break up the shell, shortly after which there is another feeding phase. The alternating sequence of shell breaking and feeding ends after 2 to 2.5 whorls when the beetle can no longer hold the prey’s remaining intact shell. We compare this previously unknown way of prey handling with the reported predatory behaviour in large snails by other Licinini species. Our observations confirm the high plasticity of predatory behaviour in Licinini beetles.

Ground beetle (Coleoptera: Carabidae) taxocoenoses from high-altitude Pinus peuce and Pinus heldreichii forests in Bulgaria

The sensitivity of ground beetles to changing habitat conditions makes them a good indicator of environmental change. The shift in their distribution could be used as an early warning signal for natural disturbances due to climate change. To reflect and monitor these changes, initial information is needed on carabid taxa in different high-altitude habitats, including the endemic and climate-sensitive tertiary relict coniferous forests of Pinus peuce (Macedonian pine) and Pinus heldreichii (Bosnian pine). Data on the carabid beetles in the different coniferous habitats in Bulgaria are scattered in various faunistic or taxonomic publications, and there is no exact information about their taxocoenoses in the Macedonian and Bosnian pine habitats. The present study aims to clarify the species composition and diversity patterns of ground beetles in these habitats in Bulgaria. Six sample sites were selected: five natural forest stands in the Rila Mts and Pirin Mts and one forest plantation in the Vitosha Mts. A total of 18 species and subspecies typical of forest habitats were recorded. Five of them were endemic to Bulgaria and five to the Balkan Peninsula. The most common species and the eudominant in the majority of the sample sites was Calathus metallicus aeneus. The exception was one of the Bosnian pine sample sites. Here, the dominant species was Xenion ignitum. The ground beetle species found in the studied forests were mostly zoophagous, mainly crevice or burrowing stratobionts in leaf litter, rocks and soil, a few epigeobionts, one botrobiont and one mixophytophagous geohrotobiont. The classification of the carabid taxocoenoses according to their qualitative composition showed two main clusters: the first being the carabids from the studied sites of the Vitosha and Rila Mts, and the second being the taxocoenoses from the Pirin Mts. The Bosnian pine habitats provide more favourable conditions for the high-altitude ground beetles, where they are in a state of equilibrium with higher species richness and evenness compared to those inhabiting the Macedonian pine forests. The forest communities of Pinus peuce and Pinus heldreichii in Bulgaria are of high conservation importance for the ground beetle and an even higher level of protection of these habitats is required.

Responses of diversity and morphometric traits of ground beetles to soil chemical properties in industrial city of China

Industrial and agricultural activities result in the direct release of contaminants into soil, which alters and destructs the habitats of soil biota. Clarifying the effects of soil contamination on soil organisms can provide a theoretical basis for the conservation of soil organisms. In this study, 3 nonmetal elements (total C, total N, total P), 5 light metal elements (total K, Ca, Mg, Al, Na), 5 heavy metal elements (Fe, Hg, Pb, Mn, Zn) and soil pH, and 18 morphological traits of carabid species were analysed to explore the responses of spatial variation of species diversity, community composition and morphometric traits to differences of soil chemical properties in four sites (Cement Plant, Coal Coking Plant, Village and Nature Reserve) in Gujiao City, the largest coking coal production city of China. In total, 1095 carabid beetles representing 59 species were recorded, with the greatest richness and activity abundance of ground beetles were found in Cement Plant and the largest species diversity was found in Coal Coking Plant, Nature Reserve contained carabid assemblages distinct from the other three sites. As for species distribution, 14 soil chemical properties could be associated with 43.2% of the observed variation, with soil Zn, N, Ca and Mn being the most important in explaining the spatial variation of the species. Changes in the type of economic activity had a significant influence on the 18 morphometric traits of carabid species, species of Coal Coking Plant and Nature Reserve had larger morphological traits than the other two sites. Variations in morphometric traits showed a significant correlation with soil chemical properties, especially body wide and profemora length, with 14 soil factors explaining more than 60% of their variance. Soil Mg, Mn, total N and pH value contributed the most in explaining morphometric traits variability of ground beetles. In summary, changes in soil chemical properties due to industrial and agricultural activities have led to carabid species diversity, community and morphometric traits changes. Soil health management is prerequisites that contribute to conserve soil biodiversity and function in industrial areas.

Do carabids struggle to recolonize restored grasslands in the fragmented landscapes of Northern Belgium?

Abstract Semi‐natural grasslands in Western Europe are degrading and declining. Their plant species diversity and associated fauna, such as arthropods, are decreasing fast making restoration crucial. Carabid beetles are an essential link in ecosystem functioning (e.g., through herbivory and predation) and provide important ecosystem services (e.g., pest control). As a diverse group from different trophic levels, they occupy a variety of ecological niches, making them good indicators of restoration success and habitat quality. To study how different aspects of carabid diversity change along a restoration gradient from degraded grasslands to restored semi‐natural Nardus grasslands, we sampled carabid beetles in grasslands in Northern Belgium. We analysed differences in abundance, diversity and community composition and investigated carabid traits potentially influencing carabids' response to grassland restoration. Species richness did not change along the restoration gradient, but number of individuals decreased as grassland restoration time and effort increased and species composition changed, mostly caused by species turnover. As grassland restoration time and effort increased, carabid body size decreased and the proportion of day‐active carabids increased. Predators and habitat generalists were dominant along the entire gradient. Even though the target vegetation was restored, the carabid communities were not, or at least, did not possess yet traits to be expected from a restored community. The landscape in Northern Belgium might be too fragmented for larger species with low dispersal ability to recolonize restored grasslands. However, restored species‐rich grasslands are beneficial for conservation of meadow birds as day‐active beetles thriving in restored grasslands are an important food source.

The Crystal-Wonder Cave System: A New Hotspot of Subterranean Biodiversity in the Southern Cumberland Plateau of South-Central Tennessee, USA

The Crystal-Wonder Cave System developed in the Western Escarpment of the southern Cumberland Plateau in the Interior Low Plateau karst region of south-central Tennessee, USA is a global hotspot of cave-limited biodiversity. We combined historical literature, museum accessions, and database occurrences with new observations from bio-inventory efforts conducted between 2005 and 2022 to compile an updated list of troglobiotic and stygobiotic biodiversity for the Crystal-Wonder Cave System. The list of cave-limited fauna includes 31 species (23 troglobionts and 8 stygobionts) with 28 and 18 species documented from the Crystal and Wonder caves, respectively, which represents five phyla, ten classes, nineteen orders, and twenty-six families (six arachnids, three springtails, two diplurans, three millipedes, six insects, three terrestrial snails, one flatworm, five crustaceans, and two vertebrates, respectively). The Crystal-Wonder Cave System is the type locality for six species—Anillinus longiceps, Pseudanophthalmus humeralis, P. intermedius, Ptomaphagus hatchi, Tolus appalachius, and Chitrella archeri. The carabid beetle Anillinus longiceps is endemic to the Crystal-Wonder Cave System. Sixteen species are of conservation concern, including twelve taxa with NatureServe conservation ranks of G1–G3. The exceptional diversity of the Crystal-Wonder Cave System has been associated with several factors, including a high dispersal potential of cave fauna associated with expansive karst exposures along the Western Escarpment of the southern Cumberland Plateau, a high surface productivity, and a favorable climate throughout the Pleistocene.

Results-based agri-environmental schemes can reflect habitat integrity for a non-target taxonomic group: Carabidae

Results-based agri-environment schemes are emerging as a valuable tool to incentivise optimal management of farmed habitats for biodiversity targets. Results-based payment schemes in Ireland use multicriteria assessments to score habitat integrity for specific targets, linking outcomes to farmer payments. Habitat integrity for a specific target is expected to have indirect co-benefits for wider farmland biodiversity. However, we lack an understanding of how results-based payment scheme assessments relate to other bioindicators of habitat integrity.Our research focuses on a results-based payment scheme which incentivises better terrestrial habitat integrity with the aim of improving watercourse quality. We explore the relationship between non-target carabid beetles, vascular plants and the results-based payment scheme’s multicriteria habitat assessment. It was anticipated that carabid beetle communities would reflect the results-based payment scheme's definition of habitat integrity across the range of scores. Pitfall trapping for carabid beetles and vegetation surveys were carried out in 19 peatland and 18 wet grassland plots, categorised into high, medium, and low habitat integrity using the scores assigned by the results-based payment scheme.We found that the results-based payment scheme’s multicriteria assessment broadly reflects habitat integrity for non-target carabid beetles in peatlands and grasslands. Eurytopic and disturbance tolerant species showed a greater association with low and medium scoring plots. Higher scoring plots supported greater diversity, with intact peatland being particularly important for hygrophilous specialists.Synthesis and application: Results-based payment scheme's multicriteria assessments have co-benefits at plot-level for non-target carabid beetles and incentivising optimal management can have positive conservation outcomes for this group. Inclusion of hydrological result indicators where relevant in results-based payment scheme assessments is recommended to reward wider biodiversity. Carabids are suitable as monitoring taxa where hydrological functioning is a results-based payment scheme priority.

The genome sequence of a carabid beetle, Nebria salina (Fairmaire & Laboulbène, 1854).

We present a genome assembly from an individual female Nebria salina (a carabid beetle; Arthropoda; Insecta; Coleoptera; Carabidae). The genome sequence is 256.7 megabases in span. Most of the assembly is scaffolded into 21 chromosomal pseudomolecules, including the assembled X sex chromosome. The mitochondrial genome has also been assembled and is 24.7 kilobases in length. Gene annotation of this assembly on Ensembl identified 10,671 protein coding genes.

Allometric constraints on carabid diets: interspecific differences in carabid-to-seed mass ratios impact seed choice

Seed choice in seed-feeding omnivorous carabid beetles (Coleoptera: Carabidae) is influenced by numerous ecological factors, including the chemical and physical properties of seed species. Previous work has shown that seed chemistry can drive seed selection decisions by carabids only when the size and mass of seed species are within certain limits. In a model system composed of eight carabid species and seeds of three brassicaceous weeds, we explored predator-to-seed mass relationships and their impact on seed choice by carabids. We show that carabid-to-seed mass ratio scaling relationships are likely to drive seed choice when seed species of different mass are presented to carabid species varying in body mass. Smaller seed species in the experiments were more preferably chosen by smaller carabid species, and mass of the preferable seed species increased as a function of the body mass of carabid species. The taxon-specific mass of carabid predators in relation to the species-averaged mass of available seeds was the main driver of seed choice decisions in the model system under study. These mass-driven changes in seed preferences suggest that feeding interactions between carabid and seed species in agricultural fields are likely driven by mass-structured dynamics. Given this, the intensity of predation pressure imposed by carabids on seed species in the field may potentially be determined by the match/mismatch between the distribution of seed mass in the weed community and the structure of functional body mass in the carabid community.

Inconsistent responses of carabid beetles and spiders to land-use intensity and landscape complexity in north-western Europe

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.

Taxonomic revision of the genus Parena Motschulsky, 1860(Coleoptera, Carabidae, Lebiini, Metallicina).

The present contribution revises the genus Parena Motschulsky, 1860, a group of arboreal carabid beetles with 46 recognized species, distributed in Tropical Asia, Sub-Saharan Africa, and the north and east coastal Australasia. We re-evaluate the infrageneric taxonomy of the genus and redefine three subgenera: Parena s. str., Bothynoptera Schaum, 1863 and Crossoglossa Chaudoir, 1872, based on the morphological characters of external features, male genitalia and female ovipositors. Under these three subgenera, we define 14 species groups to contain all known species. Keys for the identification of all subgenera, species groups, and species are provided, along with diagnostic characters, included species, geographical distribution, brief discussion on monophyly and relationships for each subgenus and species group, ample species descriptions, distribution maps, habitus images, and genitalia illustrations. The previous alpha-taxonomy of the genus Parena is defective, and several species were described without genital morphological comparisons with their real adelphotaxon. Based on careful examination of a large amount of type materials, we propose 19 new synonyms: P. rufotestacea Jedlička, 1934, as a junior synonym of P. cavipennis (Bates, 1873); P. perforata (Bates, 1873), P. nepalensis Kirschenhofer, 1994, and P. kunmingensis Kirschenhofer, 1996, as junior synonyms of P. dorsigera (Schaum, 1863); P. wrasei Kirschenhofer, 2006, as a junior synonym of P. kurosai Habu, 1967; P. nantouensis Kirschenhofer, 1996 and P. kataevi Kirschenhofer, 2006, as junior synonyms of P. tesari (Jedlička, 1951); P. yunnana Kirschenhofer, 1994, as a junior synonym of P. shapingensis Xie & Yu, 1993; P. albomaculata Habu, 1979, as a junior synonym of P. malaisei (Andrewes, 1947); P. koreana Kirschenhofer, 1994, as a junior synonym of P. monostigma (Bates, 1873); P. phongsalyensis Kirschenhofer, 2011, as a junior synonym of P. quadrisignata Mateu, 1977; P. sellata (Heller, 1921), P. hastata (Heller, 1921), P. sellatoides (Jedlička, 1940), P. fasciata var. unicolor Louwerens, 1949, and P. sumatrana Kirschenhofer, 2011, as junior synonyms of P. fasciata (Chaudoir, 1872); P. nigrolineata nipponensis Habu, 1964 and P. schillhammeri Kirschenhofer, 2006, as junior synonyms of P. nigrolineata (Chaudoir, 1852); and P. alluaudi Jeannel, 1949, as a junior synonym of P. madagascariensis (Alluaud, 1917). Furthermore, the specific status of P. scutata (Alluaud, 1917) is resurrected from synonym with P. plagiata Motschulsky, 1864. Parena sticta (Andrewes, 1947) is excluded from Parena and a new combination is suggested: Peliocypas stictus (Andrewes, 1947) comb. nov. A total of eight new species are described: P. (Crossoglossa) sciakyi sp. nov. (type locality: Guadalcanal, Solomon Islands), P. (Bothynoptera) heteronycha sp. nov. (type locality: Houaphan, Laos), P. (Bothynoptera) emarginata sp. nov. (type locality: Muli, Sichuan, China), P. (Bothynoptera) gonggaica sp. nov. (type locality: Hailuogou, Sichuan, China), P. (Bothynoptera) triguttata sp. nov. (type locality: Kangding, Sichuan, China), P. (Parena) picipes sp. nov. (type locality: Trus Madi, Borneo), P. (Parena) fulva sp. nov. (type locality: Dodoma, Tanzania), and P. (Parena) ruficornis sp. nov. (type locality: Lobaye, the Central African Republic). Several of these new species are very rare in collections, with four of them known from females only.

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.