Search Results (63)

Environmental risk assessment (ERA) for pesticide approval in the context of predatory insects remains inadequate as it often overlooks the influence of agricultural practices. An increasing number of studies have shown that prolonged and synergistic pesticide exposure can elevate insect mortality. However, such effects remain largely unstudied in non-target predatory carabid beetles. The carabid beetle Platynus assimilis was subjected to repeated oral and continuous contact exposure to low doses of prothioconazole (20 g ha⁻¹), lambda-cyhalothrin (0.4 g ha⁻¹), or their combination over a 64-day period. The food consumption rate, body mass, locomotor activity, and mortality were monitored throughout the experiment. All pesticide-treated groups showed significantly increased final mortality, with median lethal times (LT₅₀) of 51.6 days for prothioconazole, 60.3 days for lambda-cyhalothrin, and 12.2 days for their combination. A significant synergistic effect on mortality was observed in the combined treatment group, with the highest synergistic ratio detected 20 days after the first exposure. Pesticide-treated beetles exhibited significant abnormalities in locomotor activity and body mass compared to the untreated group. These findings demonstrate that both time-cumulative mortality and potential synergistic interactions, reflecting field-realistic conditions, must be considered in ERA. Failure to do so may lead to an underestimation of pesticide toxicity to predatory carabids. Full article

The Carabidae family, or ground beetles, is a wide and ecologically significant group within the Coleoptera order, known for its role as natural predators of agricultural pests and as bioindicators of ecosystem health. These beetles employ a variety of behavioral, morphological, and chemical defense strategies to protect themselves from predators. These mechanisms include gregariousness, stridulation, regurgitation, and chemical defenses, such as the secretion of irritating compounds from specialized glands. The defensive strategies of carabids are classified into passive and active systems, each with varying energetic costs. Chemical substances (e.g., Formic acid, Methacrylic acid, Tiglic acid, Ethacrilic acid, Isovaleric acid, Salicylaldehyde, 1,4-Benzoquinone, Toluquinone, 13-2Kt tridecan-2-one, Undecane, Tridecane, Pentadecane, M-cresol) are particularly important, as they serve to deter predators and combat pathogens like bacteria and fungi. Ground beetles utilize both polar and non-polar compounds in their defense, all contributing to their ecological success. This review explores the array of defensive mechanisms in the Carabidae family, highlighting experimental studies, field observations, and reviews published over the last five decades. The aim is to provide a comprehensive understanding of how these strategies enhance the survival and fitness of carabid beetles in their natural environments. Full article

Ground beetles (Coleoptera, Carabidae) are common predators found in agricultural ecosystems. They feed on crop pests and help reduce pest population. Additionally, they are used as bioindicators to determine the impact of human activities on entomofauna and habitat conditions. The aim of this study was to investigate the ground beetles that inhabit chemically protected (CP) and non-chemically protected (NCP) potato crops and to assess the impact of pesticide use on these beneficial insects. This study was conducted in Poland, on potato fields where ground beetles were caught during four-year crop rotation cycles in 2004, 2008, 2012, and 2016. Two fields with potato crops were chosen: one without chemical protection and the other with chemical protection. Soil traps were used to catch insects, resulting in 7095 individuals of Carabidae, belonging to 41 species, caught throughout the study. The abundance and species richness of ground beetles fluctuated depending on the year of the study and the type of crop protection. Results showed that pesticide use in potato crops decreased ground beetle abundance while species richness remained unaffected. Furthermore, the use of chemical plant protection (CP) induced changes in some life traits of the carabids, leading to a decrease in the abundance of hemizoophages and autumn-breeding carabids. The abundance of the other ecological groups of Carabidae was also year-dependent. Full article

The Dolomites (European Alps) are a UNESCO World Heritage Site known to harbor distinctive communities of carabid beetles adapted to high-altitude environments, whose composition is shaped mainly by landform and habitat type. We aimed to assess the conservation priority of carabid beetle communities in the Brenta mountain group (Italy). We used the Index of Natural Value (INV), based on the relative frequencies and abundances of highly specialized Alpine species, as a proxy of the sensitivity to disturbance, and, thus, to the vulnerability of the carabid beetle communities to extinction. We used information on Natura 2000 habitat cover to produce a map for identifying areas of the Brenta Dolomites inhabited by the carabid beetle communities most relevant for conservation. We also report on the main differences in terms of species composition between the investigated communities. We found a positive correlation between vulnerability and altitude. Specifically, the most vulnerable communities were recorded in high-altitude habitat types (limestone cliffs and pavements, calcareous and calcschist screes, and alpine calcareous grasslands). Alkaline fens resulted in having the least vulnerable community, while those in all other habitats (bush and forests) were found to have intermediate levels of vulnerability. Full article

This paper shows the results of a study on the ecological structure and spatial distribution of communities of the protected steppe ground beetle Carabus hungaricus Fabricius, 1792 (Coleoptera: Carabidae), in Bulgaria. It also points some phenological data and details about the species activity. In the period May 2021–December 2023, we explored 42 sample plots in xerophytic landscapes in central–western Bulgaria, representing the southernmost limits of the steppe fauna in Eurasia. With 252 pitfall traps, 69,903 effective trap-days were realised, and 15,333 carabid individuals from 184 species were identified. Carabus hungaricus was established in seven sites (frequency of occurrence, F = 16.7%), with a total of 198 specimens (1.3% of all carabids and almost 4% of the total dynamic density). In these seven sites, we found 57 species, mostly open habitat dwellers. The tribe Harpalini had 33% of the species. The most species-rich genera were Harpalus (13 species), Amara (8) and Carabus (6). Calathus distinguendus was superdominant with more than 71% of all carabid specimens. Euconstant species, collected in all seven sites (F = 100%), were Carabus coriaceus and Calathus distinguendus. The two classes of life forms had almost equal proportions, 28 (49.1%) Zoophagous and 29 (50.9%) Mixophytophagous species, which is extraordinary for Bulgaria, but typical for the Eurasian steppe zone. Macropterous beetles comprised 56% of the species and brachypterous were 25%, which is comparable only with typical montane habitats. Concerning humidity preferences, mesoxerophilous carabids predominated (25 species, 44%). In relation to its ground beetle fauna, the studied complex of habitats is quite remarkable for Bulgaria and appears to be stable and characteristic for the steppe biome. Full article

The study explored the impact of floral strip width on the spider and carabid beetle communities in maize fields over two years. Three widths of floral strips (2 m, 4 m, and 6 m) were compared with maize-only control strips to evaluate species diversity and distribution. The results showed significant differences in both spider and carabid populations between floral and control strips, with 4 m and 6 m widths consistently harboring higher biodiversity. The results also showed distinct community clustering within floral strips in 2021, which became more cohesive by 2022. Further analysis validated significant community dissimilarities between different strip widths and controls, highlighting the ecological advantages of wider floral strips for enhancing natural enemy biodiversity. Spider activity density was notably higher in floral strips than in adjacent farmland, peaking at the edges of 4 m-wide strips and decreasing in 6 m-wide strips, with the lowest density in 2 m-wide strips. Carabid beetle activity density varied considerably with strip width and proximity to the edge, typically peaking at the edges of wider strips. Spiders were more responsive to strip width than carabid beetles. Based on these findings, we suggest using 4 m- or 6 m-wide floral strips to enhance biodiversity and natural pest control in agricultural landscapes; the floral strips narrower than 4 m (such as 2 m) could not support optimal biodiversity, as spiders and carabid beetles do not disperse far into the maize field, with spiders having dispersal distances of less than 3 m and carabid beetles less than 10 m. Vegetation characteristics significantly influenced spider and carabid communities, impacting species richness, diversity indices, and community structures across two study years. These insights highlight the necessity of thoughtfully designing floral strips to enhance biodiversity and natural pest control in agricultural landscapes. Full article

The environment of mountain ecosystems can change greatly in short distances as elevation increases. The effects of elevation change on the distribution and body size of carabid beetles were investigated at elevations of 750–2600 m in the Changbaishan Nature Reserve (Northeast China). The richness and abundance of carabid species decreased significantly as elevation increased. However, the change trends are different in forests and tundra. In the broad-leaved Korean pine forest and coniferous forest at low elevations, carabid beetle species have high richness and abundance. The community composition of carabid beetles was significantly different at different elevations and among different vegetation types. Some species only occurred at specific elevations. There were fewer indicator species in high-elevation areas, but Carabus macleayi Dejean, Nebria pektusanica Horratovich and Pterostichus jaechi Kirschenhofer were mainly found in high-elevation areas. The average body size of species in the carabid beetle community was negatively correlated with elevation. The sizes of the larger Carabus canaliculatus Adams and Carabus venustus Morawitz were negatively correlated with elevation. Their body sizes decreased obviously in the tundra at elevations above 2000 m. Changes in vegetation types at high elevations affect the distribution and body sizes of beetles along the elevation gradient. Some large carabid species may be smaller at high elevations where a unique insect fauna has developed. The body size and distribution range of the carabid may be the factors that affect body size reduction at high elevation. Although some high-elevation species also occur in low-elevation areas, the protection of species diversity in high-elevation areas should be emphasized in the context of global climate change. The results illustrate the mechanisms of carabid beetles’ response to elevation change and the need for carabid beetles’ diversity conservation under global climate change. Full article

Urbanization profoundly alters environmental conditions for organisms, particularly through the urban heat island (UHI) effect, which elevates temperatures in city centers. This study examines the influence of urban environmental variables on rove and ground beetle communities. We sampled 36 grasslands in Rennes (northwestern France), yielding 3317 and 505 staphylinid and carabid adult individuals, respectively, belonging to 121 and 60 species, respectively. Staphylinid and carabid communities are not primarily affected by temperature-related variables. Staphylinids, often overlooked in urban ecology, showed species composition variation to be influenced by habitat and temperature, whereas their functional diversity was positively correlated with herbaceous vegetation height only. In contrast, carabid communities exhibited no significant relationship with the tested environmental variables. This study underscores the taxon-dependent nature of ectotherm’s responses to thermal environments. Although a further investigation into species-specific traits, and particularly dispersal capacities in staphylinids, is needed to advance our understanding of urbanization’s impact, our results indicate that functional diversity in staphylinid assemblages can be favored by locally reducing the mowing frequency or increasing the cutting height within urban green spaces. Full article

Carabidae, or carabids, commonly known as “ground beetles”, are found in numerous natural and cultivated habitats and are recognized for their beneficial role in controlling phytophagous pests in various temperate agroecosystems. However, the crop type and agricultural practices used in management areas significantly affect the structure of the carabid communities. The aim of this study was to investigate the abundance and diversity of ground beetles in hazelnut agroecosystems characterized by different agricultural methods in Calabria, Southern Italy. The carabids were collected from 2017 to 2018 in three hazelnut groves referred to in this study as AZ1, AZ2 and AZ3. Carabids were sampled using pitfall traps inspected every two weeks over a period of 24 months. A total of 4665 specimens belonging to 48 taxa were collected within the sampled sites. Many taxa were found to be widely distributed across the three selected hazelnut groves. Among these, Calathus spp., Harpalus dimidiatus (P. Rossi, 1790), Nebria spp., Platyderus neapolitanus jannonei (Binaghi in Magistretti, 1955), Poecilus cupreus (Linnaeus, 1758), Pterostichus melas italicus (Dejean, 1828), and Syntomus obscuroguttatus (Duftschmid, 1812) were the most abundant ones associated with all sampled areas. Concerning trophic preference, among the collected taxa, the most abundant ones were zoophagous and zoospermophagous. Additionally, taxa uncommon in agroecosystems but with ecological relevance, such as Carabus lefebvrei lefebvrei Dejean, 1826, Carabus preslii neumeyeri Schaum, 1856, and Carabus rossii Dejean, 1826, were also collected. Full article

The identification of patterns and mechanisms of wildfire effects on biodiversity is of significant conservation importance. The research was conducted in a zone of mixed and broad-leaved forests. Carabid beetles were studied in eight sample plots that varied in relation to the 2010 and 2021 fires through 2022 and 2023. A total of 8667 specimens of 108 species of carabid beetles were counted. In 2022, plots were clearly differentiated by the pyrogenic disturbance in terms of the carabid species structure. As the pyrogenic disturbance increases, the total abundance of brachypterous as well as herbivore species decreases sharply. The carabids that were the most prevalent in an undisturbed forest (Carabus arcensis, Carabus glabratus, Pterostichus oblongopunctatus, and Amara brunnea) demonstrated sensitivity to the 2010 fire. The pyrophilous species Pterostichus quadrifoveolatus and Sericoda quadripunctata were attracted to a moderately burned area. Poecilus lepidus is confined to areas burned in 2010 and not affected by the 2021 fire. A moderately burned area was characterized by increased abundance and number of species. In 2023, the degree of similarity of carabid populations between sample plots did not generally increase, but only the 2010 fire was identified as a significant factor in population differentiation. The abundance of carabids decreased in a moderately burned area and an unburned area near the fire edge. The abundance and number of species increased markedly in heavily burned areas due to open habitat species, while the abundance of Carabus arcensis and Amara brunnea decreased in unburned areas. Forest megafires threaten the biodiversity of carabid beetles in pine and secondary forests. Full article

Pitfall traps provide a cost-effective method of studying the diversity and abundance of ground-dwelling arthropods, such as beetles and spiders. Their efficiency depends on factors such as size, shape, and substances used to kill or preserve the specimens. Entomologists often employ covers on pitfall traps to prevent dilution of fixation liquids or keep the traps open. In this study, we investigated whether the presence or absence of covers, as well as their colour (black versus translucent), over pitfall traps has an impact on the species diversity and abundance of carabid beetles and harvestmen. These arthropods serve as common examples of ground-dwelling invertebrates, both in forest and meadow environments. Our findings revealed that traps with black-coloured coverings captured significantly higher numbers of beetles than translucent traps, but the uncovered traps were not significantly different from the two. The species richness tended to be highest in uncovered traps. The uncovered traps were the most efficient in capturing adult harvestmen, followed by translucent and black covers in terms of adult harvestmen abundance and diversity. In conclusion, the use of covers on pitfall traps significantly affects the estimates of arthropod abundance and should be taken into account in future research. Full article

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. Full article

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. Full article

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. Full article

Epigeic generalist predators play a crucial role in terrestrial ecosystems, connecting aboveground and belowground food webs. Using stable isotope compositions (δ¹³C and δ¹⁵N values), we assessed the trophic niches of the two main groups of generalist predators (ground beetles (Coleoptera, Carabidae) and spiders (Arachnida: Aranei)), as well as their potential prey (phytophagous and saprophagous insects), plants, and soils in the forest, steppe, and transitional ecosystems located in the forest–steppe of southwestern Siberia. We hypothesized that (1) the trophic niche of carabids is wider than that of spiders, because some ground beetles are omnivorous, and (2) the contribution of invertebrates from the detrital food web (saprophages) to the diet of generalist predators is higher in the “detrital” forest ecosystem than in the steppe, which should be reflected in increased δ¹³C and δ¹⁵N values of the predators in the forest. In total, 16 species of carabid and 17 species of spider were analyzed. The δ¹⁵N values of ground beetles suggested a wide range of trophic niches corresponding to two or three trophic levels. Omnivorous carabids of the genera Amara and Harpalus had the minimum δ¹⁵N values. The carbon isotope compositions of the ground beetles suggests that most predatory species were predominantly involved in grazing food chains. Spiders had on average increased δ¹⁵N values compared to ground beetles, and a relatively narrow range of δ¹⁵N values. The isotopic niche occupied by spiders hardly overlapped with the isotopic niche of carabids, which may indicate a significant difference in the range of consumed resources. Thus, our data suggest a significant difference in the trophic niches of the key generalist predators, ground beetles and spiders, which was observed both in the forest and the steppe habitats. Spiders appear to be more closely associated with detrital food webs than ground beetles. Contrary to our expectations, we did not find higher δ¹³C and δ¹⁵N values in ground-dwelling generalist predators in the forest compared to the steppe ecosystem. Full article