Response of the dung beetle community to different climatic zones: Does the land use system matter?

The conversion of Brazilian savanna into exotic pastures leads to the loss of dung beetles and a decrease in their contribution to ecological functions. We hypothesized that the dung beetle communities from exotic pastures would show greater significant differences between climatic zones, when contrasted to communities from Brazilian savanna in the same region, since dung beetle assemblages in pastures are more simplified. We assessed which variables (purpose of production, type of management, percentage the habitat per buffer, soil penetration resistance, pasture area and herd size) affect more the dung beetle community in exotic pastures. We carried out this study in 48 areas of native Brazilian savannas and exotic pastures distributed across four bioclimatic zones: BZ1, hot with three dry months; BZ2, hot with 4–5 dry months; BZ3, sub-hot with 4–5 dry months and BZ4, meso-thermal with 4–5 dry months of Minas Gerais State, Brazil. In each BZ, six areas of Brazilian savannas and six areas of exotic pasture were selected. In the Brazilian savanna areas, the species richness, abundance and biomass of dung beetles did not differ between the bioclimatic zones, unlike the exotic pastures. The composition of the dung beetle community was different between land use systems and between bioclimatic zones; the interaction between the two factors was also significant. Our results provide evidence that dung beetle communities active in exotic pastures are more susceptible to climatic environmental variations than communities from more complex and stable habitats, such as savannas. Finally, the best model suggested that all the six variables combined explained about 91% of the total variability in species composition observed between sampling sites.     

Abrupt species loss of the Amazonian dung beetle in pastures adjacent to species-rich forests

Anthropogenic disturbances, such as conversion of forests to pastures, are considered one of the major causes of Amazonian biodiversity loss. Pastures are hostile environments for forest species that are not adapted to the adverse conditions of open areas. The aim of this study was to analyze the effects of forest replacement by cattle pastures in the north-eastern part of the Amazonian rainforest using dung beetles (Scarabaeidae: Scarabaeinae) as indicators. Therefore, we determined edge effects and differences in dung beetle species richness, composition, and abundance between forest and neighbouring cattle pastures. A total of 6723 individuals of 63 species of dung beetle were collected. In comparison to forests, adjacent pastures were sharply less rich and abundant in dung beetles. The forests had 6604 individuals and 59 species, while the pastures had 119 individuals and 12 species. The replacement of forests by pastures results in an increase of dung beetle species turnover. Only 12% of dung beetle species were shared by both forest and pasture environments. We highlight that most Amazonian dung beetles are forest species sensitive to abrupt human-driven modification of habitats and are only moderately affected by edge effects.     

Diversity, distinctiveness and conservation status of the Mediterranean coastal dung beetle assemblage in the Regional Natural Park of the Camargue (France)

The Mediterranean region as a whole has the highest dung beetle species richness within Europe. Natural coastal habitats in this region are among those which have suffered severe human disturbance. We studied dung beetle diversity and distinctiveness within one of the most important coastal protected areas in the west Euro‐Mediterranean region (the regional Park of Camargue, southern France) and made comparisons of dung beetle assemblages with other nearby Mediterranean localities, as well as with other coastal protected area (Doñana National Park, Spain). Our finding showed that: (1) The species richness of coastal habitats in the Camargue is low and only grasslands showed a similar level of species richness and abundance to inland habitats of other Mediterranean localities. The unique habitats of the coastal area (beaches, dunes and marshes) are largely colonized by species widely distributed in the hinterland. (2) In spite of their low general distinctiveness, dune and marsh edges are characterized by the occurrence of two rare, vulnerable, specialized and large roller dung beetle species of the genus Scarabaeus. As with other Mediterranean localities, current findings suggest a recent decline of Scarabaeus populations and the general loss of coastal dung beetle communities in Camargue. (3) The comparison of dung beetle assemblages between the Camargue and Doñana shows that, in spite of the low local dung beetle species richness in the Camargue, the regional dung beetle diversity is similar between both protected areas. Unique historical and geographical factors can explain the convergence in regional diversity as well as the striking divergence in the composition of dung beetle assemblages between both territories.     

Dung beetle community composition affects dung turnover in subtropical US grasslands

1. An important service in many ecosystems is the turnover and degradation of dung deposited by cattle. Dung beetles are the primary group of insects responsible for dung turnover, and factors affecting their abundance and distribution thus impact dung degradation. Lands lost to grazing due to dung buildup and pasture contamination total millions of acres per year in US pastures.
2. We evaluated the structural differences in dung beetle assemblages in natural grasslands versus a managed agroecosystem in subtropical southeastern Florida (USA). We measured the direct effect of dung longevity when dung beetle fauna normally inhabiting dung pats were excluded.
3. Our results indicate dung beetle abundance, functional diversity, and species richness have a substantial impact on the rate of dung turnover in subtropical pastoral lands with ~70% of dung removed from the soil surface after three months. Functional diversity and evenness did not have a significant positive effect on dung removal in managed, versus natural grasslands demonstrating a strong relationship between dung beetle assemblage composition and delivery of a key ecological process, dung degradation.
4. We suggest the importance of trees, which provide a thermal refuge for beetles, should be dispersed within matrixes of open pasture areas and within proximity to adjacent closed‐canopy hammocks to facilitate the exchange of dung beetles between habitats and therefore maintain the provisioning of dung degradation services by dung beetle assemblages.

     

Patterns of alimentary resource use by dung beetles in introduced Brazilian pastures: Cattle versus sheep dung

Dung beetles (Coleoptera: Scarabaeidae) perform essential ecological functions in pastures, such as dung removal, nutrient recycling and parasite control. However, the patterns of alimentary use by dung beetles in introduced Brazilian pastures are poorly known. Here, we compared dung beetle species richness, abundance and species composition in cattle and sheep dung, and identified the dung beetle species preference by each dung type. In January 2019, dung beetles were sampled with pitfall traps baited with cattle and sheep dung in 12 introduced pastures (Urochloa spp.), in Aquidauana, Mato Grosso do Sul, Brazil. A total of 592 individuals belonging to 14 species of dung beetles were collected. Of the 14 species sampled, nine were recorded in both dung types, five were found exclusively in sheep dung and no species was exclusive to cattle dung. Species richness and abundance were higher in sheep dung. Species composition was different between the dung types. Dichotomius bos (Blanchard), Genieridium bidens (Balthasar), Onthophagus aeneus Blanchard and Trichillum externepunctatum Preudhomme de Borre were associated with sheep dung. Our results provide evidence that sheep dung is more attractive to dung beetles with a distinct community species between the two dung types, although the studied pastures have never been used before for sheep breeding. Thus, our data shows that the introduction of a new alimentary resource (e.g. sheep dung) can be an important strategy to help to obtain a more diverse dung beetle assemblage in introduced Brazilian pastures.     

Effects of Degradation and Replacement of Southern Brazilian Coastal Sandy Vegetation on the Dung Beetles (Coleoptera: Scarabaeidae)

In this paper we address the effects of anthropogenic disturbance and replacement of Brazilian Coastal sandy vegetation (restingas) on dung beetles communities. We sampled dung beetles in the four main vegetative physiognomies of Guriri Island, Espírito Santo State: forest restinga, restinga Clusia, disturbed restinga (from burning events), and pastures. We placed four sets of two pitfall traps (baited with horse and human dung) in four independent areas of each vegetation type, and collected 14,534 individuals of 13 dung beetle species. Neither log₁₀ of individuals nor log₁₀ of species richness were good predictors of restinga disturbance. However, a significant amount of variation in dung beetle abundance and richness could be explained by bait type. Ordination of these sites using hybrid multidimensional scaling revealed a gradient of habitat disturbance from undisturbed restinga samples to pasture. Dung beetle communities along this gradient demonstrated a complete turnover in species composition, from restinga‐specialists to invasive and generalists species respectively. This complete turnover signals the local extirpation of forest‐adapted species in disturbed and converted areas. Only a single dung beetle species in preserved restingas is protected by Brazilian law (Dichotomius schiffleri). Given the extent of the clearing of restinga habitat, the conservation status of dung beetles associated with restinga forest gives cause for concern.     

Do riparian reserves support dung beetle biodiversity and ecosystem services in oil palm-dominated tropical landscapes?

Agricultural expansion and intensification are major threats to global biodiversity, ecological functions, and ecosystem services. The rapid expansion of oil palm in forested tropical landscapes is of particular concern given their high biodiversity. Identifying management approaches that maintain native species and associated ecological processes within oil palm plantations is therefore a priority. Riparian reserves are strips of forest retained alongside rivers in cultivated areas, primarily for their positive hydrological impact. However, they can also support a range of forest‐dependent species or ecosystem services. We surveyed communities of dung beetles and measured dung removal activity in an oil palm‐dominated landscape in Sabah, Malaysian Borneo. The species richness, diversity, and functional group richness of dung beetles in riparian reserves were significantly higher than in oil palm, but lower than in adjacent logged forests. The community composition of the riparian reserves was more similar to logged forest than oil palm. Despite the pronounced differences in biodiversity, we did not find significant differences in dung removal rates among land uses. We also found no evidence that riparian reserves enhance dung removal rates within surrounding oil palm. These results contrast previous studies showing positive relationships between dung beetle species richness and dung removal in tropical forests. We found weak but significant positive relationships between riparian reserve width and dung beetle diversity, and between reserve vegetation complexity and dung beetle abundance, suggesting that these features may increase the conservation value of riparian reserves. Synthesis and applications: The similarity between riparian reserves and logged forest demonstrates that retaining riparian reserves increases biodiversity within oil palm landscapes. However, the lack of correlation between dung beetle community characteristics and dung removal highlights the need for further research into spatial variation in biodiversity–ecosystem function relationships and how the results of such studies are affected by methodological choices.     

Space-for-time substitution reveals a hump-shaped distribution of dung beetles

Unraveling how climate change impacts the diversity and distribution patterns of organisms is a major concern in ecology, especially with climate-sensitive species, such as dung beetles. Often found in warmer weather conditions, beetles are used as bio-indicators of environmental conditions. By using an altitudinal gradient as a proxy for climate change (i.e., space-for-time substitution), we assessed how changes in climatic variables, such as temperature and precipitation, impact patterns of dung beetle diversity and distribution in the Peruvian Andes. We recorded dung beetle diversity using three different types of baits, feces, carrion, and fruits, distributed in 18 pitfall traps in five different altitudinal sites (from 900 to 2500 m, 400 m apart from each other) in the rainy and dry season. We found that (i) dung beetle richness and abundance were influenced by the climate gradient, (ii) seasonality influenced beetle richness, which was high in the wet season, but did not influence abundance, (iii) dung beetle richness and abundance fit to a hump-shaped distribution pattern along the altitudinal gradient, and (iv) species richness is the beta-diversity component that best describes the composition of dung beetle species along the altitudinal gradient. Our data show that the distribution and diversity of dung beetles are different at larger scales, with different patterns resulting from the response of species to both abiotic and biotic factors.     

Dung beetle (Coleoptera: Scarabaeinae) persistence in Amazonian forest fragments and adjacent pastures: biogeographic implications for alpha and beta diversity

The aim of this study is to analyze the effects of habitat loss and forest replacement by cattle pasture on the alpha and beta diversity, abundance, biomass and species composition of dung beetles with different dispersal ability. Dung beetles were captured in 19 forest fragments and neighbouring pastures. Forest fragment area ranged from 3.7 to 4825 ha and in this study were grouped into four categories: small, medium, large and control forest. A total of 35,048 dung beetles representing 101 species were collected. Forest fragments had the highest richness with 81 species, followed by pasture with 58 species. Replacement of forest by pasture reduced species richness; however, due to the proximity and connectivity of these areas with Cerrado patches, pastures also had high species richness, but species composition was independent of adjacent fragments. Small fragments had lower abundance and species richness than our other habitat categories, even pastures. Our results highlight that proximity and connectivity with Cerrado areas influenced the patterns of alpha and beta diversity of dung beetles in fragments and pastures. We highlight that the ability to cross the pasture matrix is a strong adaptive trait for species living in human-modified landscapes. Consequently, species with these abilities are less susceptible to the effects of forest fragmentation and local extinction. Our results reinforce the importance of considering the biogeographic location and distribution pattern of species in forest fragmentation studies.     

Tree retention in cattle ranching systems partially preserves dung beetle diversity and functional groups in the semideciduous Atlantic forest: The role of microclimate and soil conditions

The disturbance of natural environments affects, among others, the diversity of dung beetle assemblages, which could have serious consequences for the ecological processes regulated by these insects. The objective of this study was to evaluate and compare species diversity and functional groups of dung beetle assemblages both in the native forest and in three livestock systems that differed in their structure and composition of vegetation: a livestock system with native trees, a livestock system with exotic trees (Pinus taeda), and traditional open pastures, in the semideciduous Atlantic forest of Argentina, in an area previously covered by continuous forest and currently with a heterogeneous landscape of native forest and different land uses. Pitfall traps baited with cow dung were used in the natural forests and the livestock systems studied. A total of 2461 beetles belonging to 38 species were captured. Treed livestock systems showed the highest species richness (⁰D) and diversity (¹D and ²D). Twelve functional groups were identified. The native forest showed the highest functional group richness, while open pastures had the lowest. In general, livestock systems showed a low proportional abundance of telecoprid, diurnal and large beetles. Microclimate (average temperature and humidity) and soil conditions (soil composition: sandy or clayey) were closely associated with the species and functional group composition. Results confirm that cattle ranching with tree retention preserves dung beetle diversity, and suggest that cattle systems without canopy cover have higher impact (negative effects) than silvopastoral systems on both species and functional groups.     

Differences in Coprophilous Beetle Communities Structure in Sierra de Minas (Uruguay): a Mosaic Landscape

Coprophilous beetles represent an abundant and rich group with critical importance in the functioning of terrestrial ecosystems. Most coprophagous beetles have a stenotopic distribution in relation to vegetation types. Because of this, they are usually very sensitive to environmental changes and are considered well suited as bioindicator organisms. The aim of this study was to analyze variations in coprophilous beetle assemblages in natural and anthropogenic habitats. Coprophilous beetle communities were sampled monthly for 1?year using pitfall traps baited with cow dung, in native xeric upland forests, 15-years-old plantations of Pinus elliottii and pastures in Sierra de Minas, Lavalleja, Uruguay. A total of 7,436 beetles were caught and identified to species or morphospecies level. The most abundant families were Aphodiidae, Scarabaeidae, and Staphylinidae. Differences in species richness, abundance, Shannon index, evenness, and dominance were detected between habitats. Abundances of most frequent families were significantly higher in both kinds of forests. Species richness and diversity of Aphodiidae and Staphylinidae were higher in forests, while Scarabaeidae showed the highest richness and diversity in pine plantations. Species composition significantly differed between habitats. Uroxys terminalis Waterhouse and Ataenius perforatus Harold typified the assemblages in native forests and pine plantations and also discriminated both communities because of their differential pattern of abundance between habitats. Typifying species in pastures were Onthophagus hirculus, Ateuchus robustus (Harold), and Ataenius platensis Blanchard. Habitat type had a strong effect on the coprophilous beetle community structure and composition.     

Regional and local influence of grazing activity on the diversity of a semi-arid dung beetle community

This study analyses the effect of resource availability (i.e. sheep dung) on dung beetle communities in an arid region of Central Spain, both at regional and at local scales. A total of 18 sites within 600 km² were sampled for the regional analysis and 16 sites within the 30 km² of an Iberian municipality were sampled for the local analysis. Spatial and environmental characteristics of sampling sites were also compiled at both scales, including measures of grazing activity (livestock density at regional scale, and two counts of rabbit and sheep dung at local scale). At a regional scale, any environmental or spatial variable can help to explain the variation in abundance. However, species richness was related to summer precipitation and composition was related to elevation. At local scale, abundance is not significantly related to any of the environmental variables, but species richness was related to the local amount of sheep dung (27% of variance). The amount of dung in a 2‐km buffer around the site accounts for 27–32% of variance in abundance and 60–65% of variance in species richness. The presence of the flock with the highest sheep density explains 53% of abundance variability and 73% of species richness variance. A cluster analysis of localities identified two main groups, one characterized by a lower abundance and species richness that can be considered a nested subsample of the species‐rich group. The mean and maximum amount of sheep dung in the sites separated by less than 2 km are the only significant explanatory variables able to discriminate both groups. These results suggest that grazing intensity (and the associated increase in the amount of trophic resources) is a key factor in determining local variation in the diversity and composition of dung beetle assemblages. However, dung beetle assemblages are not spatially independent at the analysed resolution, and the amount of dung in the surroundings seems to be more important for locally collected species than the dung effectively found in the site. Although differences in the availability and quantity of trophic resources among nearby sites could be affecting the population dynamics and dispersion of dung beetles within a locality, sites with larger populations, and greater species numbers would not be able to exercise enough influence as to bring about a complete local faunistic homogenization.     

Dung beetle communities as biological indicators of riparian forest widths in southern Brazil

Riparian forests provide important habitat for many wildlife species and are sensitive to landscape change. Among terrestrial invertebrates, dung beetles have been used to investigate the effects of environmental disturbances on forest structure and diversity. Since many studies demonstrated a negative response of dung beetle communities to increasing forest fragmentation, and that most dung beetle species had a more pronounced occurrence during warmest seasons, three hypotheses were tested: (1) Scarabaeinae richness, abundance, diversity and evenness are lower in thinner riparian zone widths than in wider widths during the warmest seasons; (2) Scarabaeinae richness and abundance are positively influenced by leaf litter coverage and height and canopy cover; and (3) Scarabaeinae composition varies with the reduction in riparian vegetation and among annual seasons. We selected four fragments with different riparian zone widths in three secondary streams in southern Brazil. In each fragment, four sampling periods were carried out seasonally between spring 2010 and winter 2011. We collected dung beetles using pitfall traps with two types of bait. We collected 1289 specimens distributed among 29 species. In spring and summer, dung beetle richness was higher in fragments with the widest riparian zone than in those with a thinner riparian zone, and it did not vary between fragments in fall and winter seasons. Dung beetle abundance did not differ among fragments with different riparian zone widths, but it was higher in spring and summer than fall and winter. Richness and abundance were positively influenced by leaf litter. While dung beetle diversity was higher in fragments with wider riparian zone widths than in those with thinner widths, the evenness was similar among fragments. Dung beetle composition differed between the fragments with the widest and thinnest riparian zones, and it also varied among the seasons. Our results suggest that decreased riparian zones affect negatively to dung beetle community structure in southern Brazil. Fragments with thinner riparian zones had lower beetle richness in warmest seasons and an altered community composition. In this sense, the dung beetles are potentially good indicators of riparian forest fragmentation since some species were indicators of a particular riparian zone width. From a conservation perspective, our results demonstrate that the new Brazilian Forest Code will greatly jeopardize not only the terrestrial and aquatic biodiversity of these ecosystems, but also countless other ecological functions.     

Using dung beetles to evaluate the effects of urbanization on Atlantic Forest biodiversity

We used dung beetles to evaluate the impact of urbanization on insect biodiversity in three Atlantic Forest fragments in Londrina, Paraná, Brazil. This study provides the first empirical evidence of the impact of urbanization on richness, abundance, composition and guild structure of dung beetle communities from the Brazilian Atlantic Forest. We evaluated the community aspects (abundance, richness, composition and food guilds) of dung beetles in fragments with different degrees of immersion in the urban matrix using pitfall traps with four alternative baits (rotten meat, rotten fish, pig dung and decaying banana). A total of 1 719 individuals were collected, belonging to 29 species from 11 genera and six Scarabaeinae tribes. The most urban‐immersed fragment showed a higher species dominance and the beetle community captured on dung presented the greatest evenness. The beetle communities were distinct with respect to the fragments and feeding habits. Except for the dung beetle assemblage in the most urbanized forest fragment, all others exhibited contrasting differences in species composition attracted to each bait type. Our results clearly show that the degree of urbanization affects Atlantic Forest dung beetle communities and that the preservation of forest fragments inside the cities, even small ones, can provide refuges for Scarabaeinae.     

The impact of overgrazing on dung beetle diversity in the Italian Maritime Alps

Dung beetles (Coleoptera: Scarabaeidae) are undoubtedly the most typical and ecologically relevant insects of grazed alpine habitats because they provide valuable ecological services such as biological pest control and soil fertilization. Despite the great ecological contribution of these insects to pasture ecosystem functioning, little is known about their direct or indirect relationships with pastoral activities. The main aim of the study was to assess whether dung beetle diversity was influenced by different intensities of cattle grazing. Dung beetle communities of two adjacent alpine valleys within the Maritime Alps Natural Park (north-western Italian Alps), representing overgrazed and ungrazed pastures, were studied by pitfall trapping. A hierarchical design (three levels: valleys, transects, and replicates) was established for additive partitioning of γ-diversity and Indicator Species Analysis. Evenness and Shannon diversity were significantly higher at the ungrazed than at the overgrazed site because abundances were much more evenly distributed at the former than at the latter site (where one species was dominant over all the others). Dung beetle abundance and species richness of the overgrazed graminaceous pasture vegetation types were in most cases significantly lower than those of the ungrazed nongraminaceous vegetation type. In the additive partitioning of γ -diversity analysis relative to the whole study area, the randomization procedure indicated that the contribution of β to γ-diversity was significantly different from that expected by chance, suggesting that one or more environmental factors has intervened to change the partition of total diversity in the system considered. The analysis of the preferences and fidelity of species (Indicator Species Analysis) showed that only one species chose overgrazed pastures; all the others positively selected the ungrazed site, or the only ungrazed pasture vegetation type (Rumicetum alpini Beger) occurring at the overgrazed site. Results conformed to evidences that overgrazing represents a serious threat to the conservation of alpine dung beetles. To conserve local dung beetle assemblages, especially in protected areas, cattle overgrazing should be avoided. This does not mean, however, that pastoral activities are incompatible with biodiversity conservation. The contemporaneous presence of wild ungulates and low intensity extensive pastoral activities may be useful to preserve both local dung beetle assemblages and alpine pasture ecosystems.     

Large-scale spatial ecology of dung beetles

Recent modelling work shows that the composition of local communities can be influenced by the configuration of the surrounding landscape, but many of these models assume that all community members display the same type of extinction‐colonization dynamics. I use Aphodius dung beetles to test the hypothesis that interspecific differences in habitat selection and dispersal capacity may translate into differences in spatial population dynamics, even among closely related species coexisting on the same resource. If this is true, then groups of species with different characteristics would show different responses to landscape configuration. I first divided the area of Finland into a grid, and used collection records to describe regional variation in the Aphodius fauna of open cattle pastures. I then sampled dung beetles on 131 cattle farms, to examine whether the subset of species found on each farm was related to the density of pastures in the surrounding grid square. Finally, I used historical records to analyze changes in dung beetle communities during the last century, when there was great loss of pasture. Overall, I found no relationship between landscape characteristics and the total proportion of the regional species pool that was found on each farm. However, the distribution of species among guilds with different habitat specificity did relate to the configuration of the landscape, and the pattern was most pronounced in a specialists species with limited dispersal. Associations between community structure and landscape configuration were superimposed on two much larger and stronger patterns: a large‐scale latitudinal gradient in regional species richness, and a decelerating gain of species to local communities with an increasing regional species pool. I conclude that ecological variation among community members is a crucial factor in the analysis of local community composition, and that local species richness should always be conditioned on regional richness.     

Dung Beetle Assemblages and Seasonality in Primary Forest and Forest Fragments on Agricultural Landscapes in Budongo, Uganda

Very little is known about the diversity of arthropods in the fast-disappearing fragments of natural forests in sub-Saharan Africa. This study investigated: (1) the influence of forest fragment characteristics on dung beetle species richness, composition, abundance, and diversity; and (2) the relationship between dung beetle assemblages and rainfall pattern. Beetles were sampled through 12 mo using dung baited pitfall traps. A total of 18,073 dung beetles belonging to three subfamilies and 45 species were captured. The subfamily Scarabaeinae was the most abundant (99%) and species rich (89%). Fast-burying tunnellers (paracoprids) were the most dominant functional group. Catharsius sesostris, Copris nepos , and Heliocopris punctiventris were the three most abundant species, and had the highest contributions to dissimilarities between forests. With few exceptions, dung beetle abundance, species richness, and diversity were generally higher in larger forest fragments (100–150 ha) than in smaller ones (10–50 ha) and the nature reserve (1042 ha). Forest fragment size had a highly significant positive relationship with beetle abundance, but only when the nature reserve is excluded in the analysis. Dung beetle abundance and species richness showed direct weak relationships with litter depth (positive) and groundcover (negative) but not tree density, tree species richness, and fragment isolation distance. Dung beetle abundance and species richness were strongly correlated with monthly changes in rainfall. Results of this study indicate that forest fragments on agricultural lands in the Budongo landscape, especially medium-sized (100–150 ha) ones, represent important conservation areas for dung beetles.     

Species diversity and community structure of rove beetles (Coleoptera: Staphylinidae) attracted to dung of sika deer in coniferous forests of southwest Japan

Insect communities of mammal dung have been known as excellent model ecosystems for scientific study. Ecological surveys of diversity and seasonal patterns of coprophilous rove beetles in relation to wild mammals have rarely been conducted, although the high potential species diversity and abundance of the rove beetles are known. In order to investigate biodiversity of these beetles, we analyzed species composition, abundance, feeding guild and seasonality of rove beetles that were attracted to sika deer Cervus nippon dung by using dung‐baited pitfall traps for a 1.5‐year study in two plantations (cypress, cedar) and one secondary natural forest (pine) in Fukuoka Prefecture, southwest Japan. Consequently, saprophagous Anotylus sp. (Oxytelinae) was dominant in all forests. Analyses of feeding guild structure showed the number of individuals were dominated by saprophagous beetles, but the number of species were dominated by predatory beetles. Seasonal effects suggested that the species richness and abundance of rove beetles are possibly regulated by scarabaeoid dung beetles. These findings feature one example of a coprophilous rove beetle community.     

Changes in the dynamics of functional groups in communities of dung beetles in Atlantic forest fragments adjacent to transgenic maize crops

We investigated the composition and structure of dung beetle communities (Coleoptera, Scarabaeidae, Scarabaeinae) inhabiting areas of forest fragments next to either conventional or Bt-transgenic maize crops. The purpose of the study was to examine possible impacts of transgenic plants on non-target organisms associated with mammals through their food chain. In February 2011, we collected a total of 1502 beetles belonging to 33 species in Campos Novos, Santa Catarina state (SC), Brazil. Beetles were captured using 200 pitfall traps distributed among 20 forest fragments, 10 fragments in each site type (adjacent to conventional vs. Bt crops). In the fragments adjacent to conventional maize, 805 dung beetles from 27 species were collected. In the fragments adjacent to Bt-transgenic maize, 697 dung beetles from 27 species were caught. Dung beetle community composition was affected by fragment size and environmental complexity, and by distance between fragments. However, it did not explain the differences related to the two crop types, i.e., the functional group of dwellers was significantly over-represented in the fragments surrounded by transgenic maize. Hence, the dweller species Eurysternus francinae and Eurysternus parallelus were more frequent and abundant in fragments located near the transgenic maize, while the tunneler species Onthophagus tristis, Uroxys terminalis, Ontherus sulcator and the roller species Canthon lividus seminitens were more frequent and abundant in fragments surrounded by conventional maize. This observed impact of transgenic crops on functional group dynamics within dung beetle communities could potentially lead to impaired capacity for feces removal, seed dispersal, edaphic aeration, and incorporation of organic matter in the soil in these areas, as such ecosystem services are not performed by the dominant functional group (i.e., dwellers).     

Effects of dung-pad conditions and density on coprophagous beetle assemblages in a Mediterranean rangeland

Dung beetles highly depend on the ephemeral microhabitat dung which is food resource and larval habitat at the same time. Environmental conditions surrounding a dung pad, such as vegetation structure, have an impact on dung beetle assemblages. We investigated the influence of dung conditions and surrounding habitat characteristics on Mediterranean dung beetle assemblages in a permanently grazed landscape in northern Sardinia. We sampled the dung beetle assemblages of donkey and horse dung in three different vegetation types and assessed species richness and abundance of dung beetles. Species richness was determined by dung and surrounding habitat conditions, whereas abundance was solely affected by dung conditions. However, species richness and abundance decreased with increasing dung density. The effect of dung density on species richness varied depending on vegetation type, with dry grassland exhibiting the highest number of dung beetles species at high dung density. Species composition in dung pads was influenced by abiotic factors with dwellers being negatively affected by increasing dung-pad temperature. Our results underline the importance of diverse vegetation, particularly with respect to the complexity of vegetation which interrelates with the microclimate. Furthermore, our findings illustrate the negative effect of high dung densities on dung beetle assemblages, suggesting that the degree of the intensity of use by grazing animals is important when considering measures for the conservation of dung beetles.