A comparison of dung beetle (Coleoptera: Scarabaeidae) attraction to native and exotic mammal dung

Although the preference of dung beetles (Coleoptera: Scarabaeidae) for specific types and conditions of dung has been given substantial attention, little has been done to investigate the potential effects of exotic mammal introduction for game farms or rewilding projects. We used pitfall traps baited with various native and exotic herbivore, carnivore, and omnivore dung to evaluate dung beetle preference in the Great Plains of North America. Additionally, we analyzed of the nutrient quality of each dung type. In total, 9,089 dung beetles from 15 species were captured in 2 yr of sampling. We found significant differences (P < 0.05) in mean dung beetle capture among omnivore, herbivore, and carnivore dung, as well as differences in individual species preference for dung type. Omnivore dung was the most attractive with chimpanzee and human dung having the highest mean capture (291.1 ± 27.6 and 287.5 ± 28.5 respectively). Carrion also was highly attractive with a mean of 231.9 ± 20.6 beetles per trap (N = 8). Our results suggest definitive local preference of carrion in Phanaeus vindex Macleay and Onthophagus hecate (Panzer), while the congener, O. pennsylvanicus (Harold), was rarely captured in carrion and highly preferred omnivore dung. Preference for a specific bait type does not appear to be correlated with dung quality, mammalian diet, or origin of mammal. Results suggest niche segregation by dung type among dung beetle species.     

Trophic associations of a dung beetle assemblage (Scarabaeidae: Scarabaeinae) in a woodland savanna of Botswana

Species richness and abundance of dung beetles were assessed across a range of bait types that acted as surrogates for the food resources available in Chobe National Park, Botswana. These bait types were comprised of the dung of pig (omnivore), cattle (ruminant herbivore dropping fine-fiberd pads), sheep (pellet-dropping ruminant herbivore), and elephant (monogastric, nonruminant herbivore producing coarse-fibered droppings), and chicken livers (carrion). Species richness was similar between traps baited with pig, cattle, and elephant dung but was relatively lower in those baited with sheep dung and carrion. In traps baited with pig dung, abundance was relatively greater than in all other bait types. A cluster analysis of species abundance distributions for the 30 most abundant species identified four different patterns of bait type association at a 60% level of similarity. All but 1 of the 15 species in cluster A were attracted primarily to the dung of omnivores and pad-dropping ruminant herbivores (pig and cattle). All seven species of cluster B were attracted primarily to coarse-fibered, nonruminant herbivore dung (elephant). All four species of cluster C were primarily carrion and pig dung associated, whereas all four species of cluster D were carrion specialists. In conclusion, the most abundant species were attracted to all bait types, but most species were largely specialized to different dung types or carrion, with dung attracting the majority of the fauna in terms of both species richness and abundance.     

Does an aridity and trophic resource gradient drive patterns of dung beetle food selection across the Botswana Kalahari?

1. Aridity gradients are paralleled by both reductions in resources and decreased species richness of animals. Across the aridity gradient of the Botswana Kalahari, a reduction in mammal species richness leads to reduced density and diversity of dung types, accompanied by reduced dung beetle species richness. We investigated whether this gradient also drives changes in dung beetle food type association and specialisation owing to a loss of some dung types to the arid southwest. 2. Dung beetles were sampled from three study sites in each of the six study areas using 2 × 10 grids of pitfall traps baited with dung (pig, elephant, cattle, and sheep) or carrion (chicken livers). 3. Canonical correspondence analysis (CCA) showed that distributions of dung beetle species between bait types deviated significantly from random associations. 4. Central Kalahari assemblages were more specialist than those at the mesic and arid extremes of the gradient. 5. Patterns of selection and specialisation to bait types differed between mesic northeast and arid southwest study areas. There were specialist faunas on carrion and more generalist faunas on ruminant herbivore dung (cattle and sheep) in each region. However, specialist species associated with elephant dung in the northeast were replaced by a more generalist fauna in the southwest with an opposite trend on pig dung. 6. Reduced species richness and high species turnover from the mesic northeast to the arid southwest is paralleled by a shift in patterns of food association that may reflect changes in the diversity of food types, particularly the absence of elephant dung from the southwest.     

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.     

Attractiveness of baits to dung beetles in Brazilian savanna and exotic pasturelands

The Brazilian savanna is the second largest ecosystem in Brazil. It is also one of the most endangered, with only 20% of its habitat remaining unchanged. Agriculture and livestock have been indicated as the main agents of destruction of the Brazilian savanna. Brazilian livestock, for example, is the main reason for cultivation of exotic grasses such as Urochloa spp. (from Africa). Dung beetles are widely used in ecological assessment, mainly because they are recognized as bioindicators of environmental changes. Therefore, efficient sampling is required for any research involving the biodiversity of this group. In order to mitigate the lack of information on efficiency of the attractiveness of baits in the endangered Brazilian savanna and in exotic pasturelands, we sampled dung beetles in four native patches of the Brazilian savanna and in four areas of pastures with Urochloa spp. Dung beetles were captured with pitfall traps baited with carcass, cattle dung, human feces and pig dung, with a total sampling effort of 384 traps. We sampled 7544 individuals belonging to 43 species and 18 genera of dung beetles. Thirty‐eight species were collected in the Brazilian savanna and 24 species in exotic pastureland. In both ecosystems traps baited with human feces sampled greater abundance and species richness of dung beetles when compared with the other three baits used. Our results showed that human feces is a reliable, easy and inexpensive bait to sample greater abundance and species richness of generalist dung beetles in both native and exotic habitats, with clear structural differences.     

Oviposition preferences and antennal size in carrion flies

Carrion-feeding flies use odours emanating from the decomposing corpse as cues for oviposition and are described as generalists because the larvae feed on the corpses of diverse species. Whereas several features of the corpse may influence the oviposition choices of these flies, it is not known whether there is a preference for a particular species of corpse. We provided carrion flies with ovipositional (and feeding) choices in a field experiment, in which various odour sources were presented simultaneously. We found novel evidence of broadly consistent choices of carrion by flies from four families. Traps baited with decaying fish flesh captured the greatest number of individuals, whereas traps baited with decaying pig liver typically attracted the least. We also asked whether individuals captured in the various baits vary in antennal size, perhaps reflecting different capacities for odour detection. There was a trend for individuals of Lucilia sericata Meigen (Diptera: Calliphoridae) and the platystomatid collected from the traps baited with pig liver to have significantly larger antennae, whereas individuals of Muscina stabulans (Fallen) (Diptera: Muscidae) captured in traps baited with marine fish flesh had relatively longer antennae for their body size. Our data reveal a more nuanced pattern of oviposition behaviour in these generalist carrion flies, which may reflect differences in their preference of carrion with different nutrients, and in their capacity to detect particular odours.     

Millipede consumption and interaction between food preferences and sex in dung beetle Chalconotus convexus (Coleoptera: Scarabaeinae)

Dung beetles feed mainly on scarce and ephemeral mammalian faeces making them vulnerable to declines of mammal populations. Therefore, studying how diverse groups like the Scarabaeinae subfamily utilize alternative food sources, such as decomposing invertebrates, enhances our understanding of their distribution and resilience in defaunated areas. One poorly studied aspect of the feeding habits of dung beetles is the potential differences between the sexes and their predatory behaviour. We evaluated how the sex (male and female) of individuals of Chalconotus convexus affected individual resource attraction to different bait types. Since C. convexus is known to feed on faeces, carrion and dead millipedes, we also test whether it can predate live individuals of millipedes. We used a combination of two field samplings and one laboratory experiment, using pitfall traps baited with faeces, carrion, millipedes and millipede's defensive compounds. While the preference for millipede was not associated with sex, we found a significant relationship between faeces and carrion, where females of C. convexus are significantly less attracted to faeces when compared to males and also males are significantly less attracted to carrion when compared to females. Furthermore, we also show that while actively consuming dead millipedes, C. convexus is unable to predate on live individuals. Our study illustrates that the versatility of food sources may help to explain the high abundance and wide distribution of C. convexus in Africa.     

Using dung beetles to evaluate the conversion effects from native to introduced pasture in the Brazilian Pantanal

The Pantanal is the largest Neotropical seasonal freshwater wetland on Earth. Extensive livestock production has been the dominant economic land use activity of the Pantanal, where approximately 80 % of the land is occupied by native and introduced pastures. However, the impact of native pasture conversion into introduced pasture on the biodiversity of this biome is little understood. Here we evaluate the effect of native pasture to introduced pasture conversion on dung beetle communities. We sampled dung beetles in July 2011 (dry season) and January 2012 (rainy season), at four native pasture sites and four introduced pasture sites in Aquidauana, Mato Grosso do Sul, Brazil. The sampling was carried out using pitfall traps baited with three different bait types: carrion, cattle dung, and human feces. We sampled 7086 individuals, belonging to 32 species of 16 genera and six tribes of dung beetles. The abundance was similar among the pasture types. However, a higher species richness was found on the native pasture. Species composition also differed between the two pasture types in each sampling season. Additionally, the dominant functional guilds were different in the two landscapes. The result shows that the conversion of native grasslands into introduced pasture results in a decrease of species number and changes in species composition. These findings highlight the importance on native pasture to the conservation of dung beetle biodiversity in this ecosystem.     

Diversity and seasonal fluctuations in dung beetle (Coleoptera) community in Kurukshetra,India

Five pitfall traps baited with 150–200 g of fresh cattle dung were installed for 24 h at weekly intervals. A total of 991 dung beetles from 11 genera, 31 species and three subfamilies was obtained. The community was dominated by Oniticellus spinipes individuals by 32.3%. Ten species appeared only once during the collection period and species composition and dominance changed throughout the period. The overall pattern we detected in the organization of the dung beetle community is that the species richness, abundance and diversity rise in September and the 2^nd week of October. The dung beetle community was found to be affected by season.     

The volatile organic compounds of introduced and native dung and carrion and their role in dung beetle foraging behaviour

1. The decomposition of biological material produces a plethora of volatile organic compounds (VOCs), which are implicated in the foraging behaviour of coprophagous and necrophagous insects. Dung beetles (Coleoptera: Scarabaeidae: Scarabaeinae) have an acute olfactory system used to locate food resources. Accordingly, identification of food resource VOCs potentially used in food location is integral to understanding dung beetle foraging ecology. 2. In this study, volatile emissions from dung and carrion of native and introduced animals in New Zealand were analysed using solid‐phase microextraction (SPME) and gas chromatography‐mass spectrometry (GC‐MS). Volatile profiles were compared via principal component analyses (PCAs) and cluster solutions based on attractiveness using canonical discriminant analysis (CDA). 3. A total of 115 compounds were detected from 21 food types. Statistical analyses showed that dung and carrion volatile profiles clustered according to attractiveness to the dung beetle Saphobius edwardsi, and that different dung types formed distinct clusters and grouped separately from carrion. 4. This study suggests that volatile profiles emitted by food resources used by dung beetles are complex, producing distinct odours, which potentially mediate foraging decisions.     

内蒙古典型草原家畜粪中的粪金龟子群落特征

2008年6月-2009年9月,在内蒙古典型草原放牧区,分析了马、牛和羊鲜粪中粪金龟子的物种多样性、群落结构、功能群和取食偏好.共捕获粪金龟子7805头,隶属于3科4属32种,优势种为符号蜉金龟(Aphodius comma)、游荡蜉金龟(Aphodius erraticus)和泥蜉金龟(aphodius sordec...     

Influence of carrion smell and rebaiting time on the efficiency of pitfall traps to dung beetle sampling

Dung beetles (Coleoptera: Scarabaeidae: Scarabaeinae) are very useful insects, as they improve the chemo-physical properties of soil, clean pastures from dung pads, and help control symbovine flies associated with bovine cattle. Their importance makes it fundamental to sample and survey them adequately. The objectives of the present study were to determine the influence of decaying insects trapped in pitfalls on the attractiveness of Moura pig Sus scrofa L. (Suidae) and collared peccary Tayassu tajacu (L.) (Tayassuidae) dung used as baits to lure dung beetles, and to establish how long these baits remain attractive to dung beetles when used in these traps. Some dung beetle species seemed to be able to discriminate against foul smell from decaying insects within the first 24 h, hence decreasing trap efficiency. This was more evident in peccary dung-baited traps, which proved to be the least attractive bait. Attractiveness lasted only 24 h for peccary dung, after which it became unattractive, whereas the pig dung bait was highly attractive for 48 h, after which its attractiveness diminished but was not completely lost.     

Altitudinal effects on habitat selection of dung beetles (Scarabaeoidea: Aphodiidae) in the northern Iberian peninsula

The effects or vegetation cover on the abundance and species richness of dung beetles (Aphodiidae) were examined in three altitudinal zones: lowland (520–600 m), mid-altitude (950–963 m) and highland (1230–1275 m). Pitfall traps baited with fresh cattle dung were placed in three vegetation types at each altitudinal zone: forest, heathland and pasture. Species richness was lower in forests than in the other vegetation types. The total abundance of beetles also varied with vegetation type, but the effect was dependent on altitude. Number of individuals was higher in pasture at highlands and in heathland and forest at mid-altitude and lowlands. An altitudinal dependence of distribution of individuals between vegetation types was also found for the more abundant species in the study area. These results could be explained if the local distribution of individuals between vegetation types was determined by microcli-matic factors, mainly temperature. Differences in altitude between sites are associated with temperature changes, determining the habitat selection of species at each altitude.     

Influence of land use on the taxonomic and functional diversity of dung beetles (Coleoptera: Scarabaeinae) in the southern Atlantic forest of Argentina

The degradation and replacement of native ecosystems affects both their taxonomic and functional biodiversity. However, native species may find a gradient of habitat suitability in different land uses within a region. The aim of this study was to evaluate the effect of land use on the taxonomic and functional diversity of dung beetle assemblages in the southern Atlantic forest of Argentina. Dung beetles were sampled in both the native forest (control) and different land uses (Pine and Yerba mate plantations and cattle pastures) during the 2014 summer, using pitfall traps baited with human feces and rotten meat. Samplings were taken from 20 different sites, with five replicates of each land use and the native forest (100 pitfall traps in total). A total of 1699 beetles of 27 species were captured. Canthon quinquemaculatus, Canthon conformis and Dichotomius sericeus were the most abundant species. Cattle pastures were the land use most negatively affected in their taxonomic and functional diversity, particularly large paracoprid dung beetles. Pine plantations maintained their taxonomic and functional diversity in relation to the native forest and Yerba mate plantations showed, in general, an intermediate situation. Microclimatic conditions (average temperature and humidity and maximum temperature) were correlated with functional diversity (the proportion of large paracoprid dung beetles decreased with increasing temperature) and are probably good predictors to explain the observed patterns of functional diversity of dung beetles. The development of sustainable production systems that preserve the native biodiversity requires the conservation of key components from the ecological niche of native species, especially microclimatic conditions.     

Attractiveness of Different Food Resources to Dung Beetles (Coleoptera: Scarabaeidae) of a Dry Tropical Area

Excrement scarcity is one of the main historical factors leading dung beetles to adapt to other food resources. In the Caatinga, a seasonally tropical dry forest, harsh environmental conditions seem to restrict the availability of food resources. In this scenario, the aim of our study was to experimentally investigate the attractiveness of different potential food resources to these insects in the Caatinga. Field samplings were performed, and we tested five resources in pitfall baited traps: excrement, carrion, fruits of two species of columnar cacti, and seeds of one species of Euphorbiaceae (Jatropha mollissima (Pohl)). In a controlled setting, we tested dietary preferences of Deltochilum verruciferum Felsche by offering one or two resources simultaneously. In the field experiments, 297 dung beetles (9 species) were recovered from the traps, and D. verruciferum was the most abundant species. Carrion and excrement were the most attractive resources. Controlled dietary preference tests with D. verruciferum evidenced that these beetles used all tested food resources, excrement and carrion most pronouncedly. Our findings support copro-necrophagy as the main feeding habit of D. verruciferum, but also suggest that alternative resources might be utilized if preferred resources are scarce.     

Diversity of dung and carrion beetles in a disturbed Mexican tropical montane cloud forest and on shade coffee plantations

This paper analyzes the diversity of dung and carrion beetles (Scarabaeinae and Silphidae) in four human-induced habitats of a disturbed tropical montane cloud forest: polyspecific shade coffee plantations, monospecific shade coffee plantations, tropical montane cloud forest fragments, and clear cuts. The four habitats had similar richness, species composition, and assemblage structure of dung and carrion beetles. Differences were found in abundance and biomass levels for the four dominant species in the landscape. Dung beetles were more abundant than carrion beetles, but the biomass was higher for the latter. Carrion beetles were seasonal, while dung beetles were clearly not. When forest fragments and shade coffee plantations were compared to other similar habitats in the region, the same general pattern was observed. However, forests with high disturbance and monospecific shade coffee plantations had lower species richness than forests with low and medium disturbance and polyspecific shade coffee plantations. Thus shade coffee plantations maintain connectivity between patches of cloud forest in a landscape that is strongly affected by human activities. Protecting landscape diversity appears to ensure high species richness.     

Patterns in the occurrence of saprophytic fungi carried by arthropods caught in traps baited with rotted wood and dung

Fungi from approximately 1700 individual arthropods that had been captured in traps set in aspen-dominated woodland in western Canada and baited with coyote dung, moose dung, white-rotted wood, brown-rotted wood and fiberglass were isolated in pure culture and identified. These data were analysed with principal components analysis (PCA) to determine whether different types of substrate attracted specific arthropods and whether these animals carried unique assemblages of fungi with known proclivities for the new habitat. Mycobiotic agar was used to restrict the numbers of fungi isolated and resulted in the recovery of 1687 isolates representing 65 species across 12 orders. Isolates of cosmopolitan fungal taxa such as species of Cladosporium, Penicillium, and Beauveria were the most numerous. Taxa with predilections for specific substrates, such as Myxotrichum and Cryptendoxyla that are known inhabitants of cellulose-rich materials (i.e. rotted wood), and various representatives of the keratinophilic Onygenales were recovered from arthropods attracted respectively to baits rich in cellulose and keratin. When traps were analysed according to the identity and numbers of arthropods captured, there was considerable overlap among clusters representing specific bait types, with traps baited with coyote dung being the most divergent partly because they captured significantly more arthropods than those baited with moose dung or rotted wood. When bait type was examined according to the identity and numbers of fungi on trapped arthropods the degree of overlap was also high although a few trends could be discerned. In particular traps baited with brown-rotted wood and coyote dung diverged slightly indicating that arthropods visiting these bait types were carrying somewhat different suites of fungi.     

Dung burial strategies in some South African coprine and onitine dung beetles (Scarabaeidae: Scarabaeinae)

ABSTRACT.

• 1 The dung colonization and dung burial behaviour of twelve crepuscular/nocturnal tunnelling (paracoprid) species of beetles were examined in order to identify mechanisms which might facilitate resource (dung) partitioning. The species were selected from a diverse assemblage of dung beetles, the members of which coexist in the sandy-soil regions of Natal, South Africa.
• 2 The pattern of dung colonization in relation to dung age was examined in the field using baited pitfall traps. Some species, e.g. Onitis deceptor Peringuey, Catharsius tricornutus De Geer and Copris elphenor Klug, showed a marked preference for fresh dung (1–2 days old) whereas other species, e.g. O. viridulus Boheman and Copris fallaciosus Gillet, preferred older dung (3–7 days old).
• 3 Two distinct patterns of dung burial were recognized. In the Coprini, dung burial was complete within 24–48h of pad colonization, and the level of dung burial was similar in the laboratory and in the field. In the Onitini, dung burial occurred progressively over a 12-day period, although the timing of initiation of dung burial varied between species: in O. deceptor nearly all individuals had begun burial within 2 days of pad colonization, whereas only 20% of O. viridulus had commenced dung burial by that time. However, nearly all O. viridulus had buried substantial quantities of dung by day 12.
• 4 The mass of dung buried per pair by the larger coprine beetles (100–300 g) and onitine beetles (400–1000 g) suggests that there is potential for inter- and intraspecific competition, even in pads colonized by relatively few beetles. The colonization and use of dung of different ages are discussed as means of resource partitioning in relation to the relative abilities of species to compete for dung.

     

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.     

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.