Effects of fire on the populations of ground beetles (Coleoptera, Carabidae) in an equatorial Andean páramo

Seasonal shifts in ground beetle (Coleoptera: Carabidae) species and functional composition maintain prey consumption in Western Oregon agricultural landscapes

The article presents the results of a study of the fauna and population of ground beetles (Coleoptera: Carabidae) in the conditions of the industrial city of Cherepovets. The study was conducted in 2023–2024 in areas with different levels of anthropogenic load: in the residential zone (Makarinskaya Roshcha) and the industrial zone (production site and sanitary protection zone of PJSC Severstal). The material was collected using Barber soil traps. The aim of the work was to assess the species composition, abundance and dominance structure of ground beetles as a basis for their use in bioindication of the urban environment. A total of 15 species of ground beetles from 7 genera were registered in the city. The greatest species richness (12 species) was characteristic of the residential zone, while only 6 species were found in the industrial zone. The abundance of ground beetles in the residential zone (2,38 ind./10 trap-days) was twice as high as in the industrial zone (1,19 ind./10 trap-days). The dominant species in the residential zone werePterostichus niger(Schaller, 1783) andPterostichus nigrita(Paykull, 1790), and in the industrial zone –Pterostichus niger. The Shannon diversity index confirmed more favorable conditions in the residential zone (H′ = 1,568) compared to the industrial (H′ = 1,098) and sanitary protection zones (H′ = 0,811). The analysis of the food base showed that in the residential area, the density of ground beetles is approaching the availability of their preferred food sources, indicating the intensity of trophic relations. A comparative analysis with the fauna of ground beetles in other industrial cities of Russia (Grozny, Kazan, Kemerovo) revealed a significantly poorer species composition and simplified structure of communities in Cherepovets. The results obtained indicate the high sensitivity of ground beetles to technogenic impact and confirm their promise as bioindicators for monitoring the state of the environment in urban ecosystems.

The objective of this study was to assess the similarities and differences between selected bioindicator groups within tallgrass prairie and adjacent aspen forest. Based on pitfall trapping from 1998 to 2000, species richness and abundance of ground beetles and spiders were examined across a tallgrass prairie – aspen forest ecotone located near Winnipeg, Manitoba. The abundance of spiders and ground beetles was higher in the forested portion of the transect than in the prairie section. There were 639 specimens of ground beetles collected, representing 53 species; 19 species were found only on the prairie, 19 species were found only in the forest, and 15 species were found in both habitats, although the abundance of most species was too low to confidently assign them to either habitat type. Excluding single records in any sampling year yielded 9 prairie species, 5 forest species, and 10 species found in both aspen forest and tallgrass prairie. The five most abundant species of ground beetles were Agonum placidum (Say), Pterostichus caudicalis (Say), P. femoralis (Kirby), P. melanarius (Illiger), and Synuchus impunctatus (Say). There were 4499 specimens of spiders collected, representing 92 species; 25 species were found only in the prairie, 15 species were unique to the aspen forest, and 52 species were found in both habitats. Excluding single records in any sampling year yielded 26 prairie species, 15 forest species, and 22 species found in both habitats. The five most abundant species of spiders were Pardosa moesta Banks, P. distincta (Blackwall), Agroeca ornata Banks, Centromerus sylvaticus (Blackwall), and Alopecosa aculeata (Clerck). Our study concurs with other studies in demonstrating that there are distinct assemblages of both groups of predators in each of the two habitat types.

Background: Jhunjhunu district has semi-arid climatic condition which is favorable to flourish ground beetles. Diversity of ground beetles are beneficial to agricultural ecosystem as carabid beetles are prominent decomposers and reduce population of insect pest specially, caterpillars. The present study aimed to document diversity of ground beetles which will provide first even preliminary information needed for their conservation and use in integrated pest management program. Methods: Sampling was carried out in Jhunjhunu district from January 2021 to December 2021. Four sampling sites viz., Site-A (agriculture land), Site-B (Plains are relatively flat land which is dominated by grasses, herbs and shrubs), Site-C (rocky area) and Site-D (blanks of water bodies) were selected based on different habitats situation. Carabid beetles were collected using pitfall trap, hand picking and light trap and identified by valid taxonomic keys. Result: Diversity indices authenticated a good diversity and abundance of ground beetles in the district. A total of 956 individuals of carabid beetles, representing 28 species and 19 genera belonging to 11 subfamilies viz. Harpalinae (7 species), Trechinae (7 species), Brachininae (3 species), Scaritinae (3 species), Lebiinae (2 species), Paussinae (1 species), Anthiinae (1 species), Carabinae (1 species), Pterostichinae (1 species), Platyninae (1 species), Cicindelinae (1 species) under Carabidae family were collected and identified from various habitats of study area. On the basis of total number of individuals Dromius quadrimaculatus is the most dominant species and constituted 18.62% of total beetles followed by Chlaenius bimaculatus (8.05%), Tetragonoderus intermedius (7.64%) Lophyra differens (6.80%) and Bembidion ambiguum (5.02%). The highest diversity was observed at Site-B (H=2.72, J=0.83, M=4.43) followed by Site-A (H=2.72, J=0.83, M=4.08), Site-C (H=2.52, J=0.90, M=3.48) and Site-D (H=2.25, J=0.87, M=2.25).

We used pitfall trapping to measure the species richness and relative abundance of ground beetles (Coleoptera: Carabidae) in four forest habitats on Kent Island, a 80-ha island in the Bay of Fundy, New Brunswick, Canada. Sixteen species of ground beetles representing 11 genera were identified in the forested habitats on Kent Island; the relative paucity of ground beetle species may be a result of the island’s harsh climate, dense colonies of breeding seabirds, and isolation from the mainland. Estimates of ground beetle population densities on Kent Island ranged from 50 000 to 250 000/ha. Most ground beetle species were trapped in all habitats and appeared to be habitat generalists. In a series of experiments in which we removed all ground beetles trapped daily over a 3-week period in two experimental plots, ground beetle densities remained as high as in a control plot; other ground beetles quickly moved into the experimental plots to replace beetles that had been removed. The density of ground beetles was highest in intact forest and large forest patches; in contrast, the density of invertebrates other than ground beetles (i.e., possible prey or competitors of ground beetles) was highest in open habitats and isolated forest patches, where ground beetles were less common. Removing ground beetles from experimental plots did not result in an increase in the density of other invertebrates.

Research on changes in biodiversity due to the abandonment of forestry is important in understanding the role of reserves in conservation. The aim of this study was to investigate whether changes have occurred in species richness, abundance and composition of ground, longhorn and bark beetles due to habitat changes as a result of the cessation of forest management. We surveyed ten managed and ten abandoned forest plots in two watersheds located in the north-eastern Italian alpine region, which share a common history of use, climate regimes, stand structure and topography. Ground beetles, and longhorn and bark beetles were collected with pitfall and flight-intercept window traps, respectively, from May to mid-October 2010. The three beetle taxa responded differently to changes in habitat features and management cessation. Differences in individual species responses between the two watersheds may indicate a role of management abandonment through its impact on forest habitat structure. For instance, ground beetle species mainly responded negatively to soil moisture and positively to understorey vegetation cover. Unexpectedly, saproxylic species responded variably, and often negatively, to deadwood features in these forests, but did respond positively to the volume of standing Abies alba trees. The assemblages of carabids and bark beetles differed between the two watersheds. Our results confirmed that 50 years of forest management cessation resulted in changes in the biodiversity of beetles in alpine forests, likely due to their response to changes in habitat structure. Moreover, we expect that where the unplanned abandonment of forestry practices and habitat rewilding are undergoing, like in many marginal areas of Europe, similar habitat structure dynamics and beetle responses are likely to occur spontaneously.

Remotely sensed data are frequently employed for monitoring vegetation and for estimating herbivore diversity. Their use for predicting predator arthropod species abundance and richness has also been investigated with success for ants and beetles in forests using normalised difference vegetation index ( NDVI ) and for beetles in mountain forests using light detection and ranging data. We investigated whether vegetation indices, derived from multispectral SPOT imagery could predict abundance and species richness of ground active spiders and ground beetles in a new ecological context, the floodplain meadows of the Loire River in Western Europe. Using pitfall traps, we collected carabids and spiders in the field. Maximum vegetation height, litter‐depth and plant species richness best explained species assemblages of both groups (multivariate analyses). NDVI and enhanced vegetation index ( EVI 2) were strongly related to activity‐density and species richness for ground beetles only, EVI 2 being the best surrogate. Relationships between vegetation indices and spider assemblage patterns were either non‐significant or weak. We demonstrated that EVI 2 is a good surrogate of the abundance and richness of carabid species in a temperate floodplain, and has potential as a low cost method for mapping arthropod assemblages at large spatial scales. Our approach provides a tool which contributes to biodiversity assessment at large spatial scales. It can also contribute to the prioritisation of conservation areas and early change detection, as carabids are keystone indicators.

Planting non-native tree species, like Douglas fir in temperate European forest systems, is encouraged to mitigate effects of climate change. However, Douglas fir monocultures often revealed negative effects on forest biota, while effects of mixtures with native tree species on forest ecosystems are less well understood. We investigated effects of three tree species (Douglas fir, Norway spruce, native European beech), on ground beetles in temperate forests of Germany. Beetles were sampled in monocultures of each tree species and broadleaf-conifer mixtures with pitfall traps, and environmental variables were assessed around each trap. We used linear mixed models in a two-step procedure to disentangle effects of environment and tree species identity on ground beetle abundance, species richness, functional diversity and species assemblage structure. Contradictory to our expectations, ground beetle abundance and functional diversity was highest in pure Douglas fir stands, while tree mixtures showed intermediate values between pure coniferous and pure beech stands. The main drivers of these patterns were only partially dependent on tree species identity, which highlights the importance of structural features in forest stands. However, our study revealed distinct shifts in assemblage structure between pure beech and pure Douglas fir stands, which were only partially eased through mixture planting. Our findings suggest that effects of planting non-native trees on associated biodiversity can be actively modified by promoting beneficial forest structures. Nevertheless, integrating non-native tree species, even in mixtures with native trees, will invariably alter assemblage structures of associated biota, which can compromise conservation efforts targeted at typical species composition.

Semi‐natural grasslands are commonly managed as a grazing resource for domestic livestock but, due to their unique biodiversity, they are also of conservation interest. Numerous drivers have impacted on the status of these grasslands in recent decades, most importantly changing grazing management strategies. These changes have the potential to affect the biodiversity associated with these habitats, including on some rich invertebrate assemblages. Responses, however, are often dissimilar between different invertebrate taxa. We investigated the responses of ground beetles to different grazing regimes within a replicated, controlled, long‐term grazing experiment on upland semi‐natural grassland in Scotland. Although there was substantial overlap of species composition of ground beetle assemblages in different grazing treatments, species richness, abundance and Shannon diversity of ground beetles were significantly lower in ungrazed plots than in plots subject to high‐ or low‐intensity sheep grazing. Ground beetle abundance (but not species richness or diversity) was lower in ungrazed plots compared to those with low‐intensity mixed grazing by sheep and cattle. However, no differences were identified in abundance, species richness or diversity between the three grazed treatments. Our results suggest that ground beetles may show different responses to grazing compared to responses of some other invertebrate groups and demonstrate the difficulty of attempting to manage grazing to optimise conditions for a wide range of invertebrates.

In the years 1995 to 1997, following recultivation activities, investigations refering to the colonisation by ground beetles were lead through at four sites in the open-cast mining area Königsaue by means of pitfall traps. Altogether 74 species could be proved, 19% of these species are considered as endangered. The occurrence of the tiger beetle Cicindela arenaria viennensis is remarkable for nature conservation reasons, because this species is threaten by extinction in Germany. The most frequent species in the exhausted open-cast mining area were Calathus ambiguus and Bembidion femoratum . On a site nearly without any vegetation Amara fulva belonged to the dominant species. Species- and dominance-identities between the ground beetle communities of the four sites were low. Also the species turnover between the years of investgation was relatively high. A Benjes-hedge, which was planted in 1996, was investigated additionally. Pitfall trap catches within stands of various crops (winter wheat, summer wheat, maize, peas, sugar beet) nearby the open-cast mining area were carried out in 1995 to 1997 as well. The fields were treated conventionally on tschernosem soils and peaty soils. 67 species of ground beetles were registrated in the fields. The results with regard to species composition and dominance structure resembled those which had been obtained in former investigations lead through near Halle (Saale) and Obhausen (Querfurter Platte). On the peaty soils Dyschirius globosus was very numerous, whereas it was not found on the other fields. An extremly high activity density of ground beetles with more than 20 individuals per day and pitfall trap could be observed in a sugar beet field near Schadeleben. Additional investigations on field edges at another site were realized in 1996. As a whole in the cause of this research 101 species of ground beetles could be proved in the district Aschersleben-Staáfurt, among these many endangered species.

In Canada, ground beetles (Carabidae) are abundant and diverse in agricultural ecosystems. Adults of all species are well characterized, but only 10% are known in the immature stages. In a typical agricultural site, one could find 40 to 60 species. While the ground beetle species composition consists mainly of native species in agriculture sites in the Prairie regions, a mixture of local and accidentally introduced species is the norm elsewhere. Although the diversity of introduced European species is not as great as that of native of ground beetles, the absolute number of European species may dominate an agricultural site. The basic biology and habitat requirements of almost all species occurring in agricultural habitats are known. Each species of beetle has special requirements based on soil type, moisture, pH, and light exposure. They are excellent indicators of habitat modification and of the quality of the environment. Although, most species of ground beetles are predators or scavengers, some are seed feeders. Because of their positive contribution to agricultural ecosystems, maintaining and developing their diversity by providing refuge habitats is recommended. Cropping sequence and type of crop influence ground beetle populations. More important, pesticides of all kinds reduce to various degrees the number of species and specimens. Female fecundity is a most sensitive test of sublethal pesticide effects on groun d beetles and should be considered in future studies of non-target insects. Key words: Ground beetles, carabidae, diversity, ground beetles and agriculture, ground beetles and pesticides, ground beetle extirpation

Species assembly in ground beetle (Coleoptera: Carabidae) communities in local microhabitats was studied in a forest. The following questions were addressed: are there important filters that sort the species in the assemblages? If so, what is the specific nature of these filters? In order to address these questions rarefaction analysis was used to determine whether ground beetle species are distributed non-randomly. Next, the nature of filters was determined by analyzing (1) the community matrix and searching for the consequences of competitive exclusion and (2) species-environmental relations. Rarefaction analysis revealed that the species composition is filtered: species richness was less than expected and there were fewer than expected congeneric species coexisting at high beetle population densities. However, community matrix and body size analyses did not detect significant competition among the beetle species and the matrix was significantly nested. Species-environmental analyses indicated that the ground beetle assembly was strongly linked to ground vegetation. It is concluded that spatial distribution of ground beetles across local communities in this forest habitat is determined more by local environmental conditions than competition, and ground beetles do not interact strongly among themselves so that competitive effects do not play an important role in their distribution except at high beetle population densities.

Responses of predatory invertebrates to seeding density and plant species richness in experimental tallgrass prairie restorations

Molecular gut-content analysis allows determination of pest predation by field-collected predators. Ground beetles (Coleoptera: Carabidae) common in lowbush blueberries may consume blueberry spanworm, Itame argillacearia (Packard) (Lepidoptera: Geometridae), and blueberry flea beetle, Altica sylvia Malloch (Coleoptera: Chrysomelidae), providing pest suppression. Using newly developed pest specific primers, laboratory feeding trials showed that the median detection time (MDT) for blueberry spanworm in the largest beetle, Carabus nemoralis O.F. Muller, was 3.7 h, whereas Poecilus lucublandus (Say) and Pterostichus mutus (Say) had MDTs between 27.1 and 31.6 h for both pests. At a field-site with high pest abundances, the probability of detecting blueberry spanworm and blueberry flea beetle DNA was greater in P. lucublandus, 26 and 39 % respectively, than in P.mutus, 8 and 20 % respectively. Only 0 and 1 % of P. lucublandus and P. mutus, respectively, tested positive for blueberry spanworm DNA at a second site with low abundance. At the first site, the probability of detecting pest DNA in both ground beetle species was positively related to pest density. Higher pest DNA detection rates and captures of ground beetles corresponded to field areas where significant pest reductions occurred from late May to early June. Conservation of predatory carabid beetles could lead to valuable biological control in lowbush blueberries.

The recovery of vegetation following fire has been studied intensively in Mediterranean-type ecosystems. Little attention, however, has been given to floral traits, and almost no data have been collected on the effects of fire on pollinator activity and fruit-set. This paper reports the effects of fire on flower visitation rates and the possibly related fruit-set. We compared visitation rates of the main pollinators on four plant core-species in burned and adjacent unburned areas. Measurements were performed at an unburned phrygana (scrub lands), and at a burned area (5‐7 years post-fire). Bumble bees and solitary bees were the main taxa of visitors, while few honeybees were recorded. Solitary bees were almost absent from the burned area. Fruit-set was significantly higher in the unburned area for three out of the four plant species. The lower fruit-set in the burned area was possibly the result of low activity of solitary bees which are the main effective pollinators of the examined species. We hypothesize that the populations of the solitary bees were diminished or extirpated either directly by the fire, or indirectly by the scarcity of nectar in the early post-fire years due to dominance of young pine and Cistus spp. seedlings. The short foraging range of the solitary bees and their slow invasion rate into the burned area may explain our results.