Delaying insect access alters community composition on small carrion: a quantitative approach

We present a study of interactions in the highly competitive insect communities inhabiting the carrion of small mammals. Via manipulation in a fully quantitative design, we delayed community development by excluding insect colonization in mouse and rat carcasses for 3 days, to study the role of early competitively dominant colonizers [burying beetles (Nicrophorus spp.; Coleoptera: Silphidae) and blowfly larvae (Diptera: Calliphoridae)] in the course of heterotrophic succession on small cadavers. Earlier studies demonstrated that in the case of large mammalian carrion, exclusion of insects’ access to the carcass in the early stages of decomposition altered the successional trajectory and species assemblages. However, the effect of such manipulation in easy monopolizable small vertebrate carrion remained unknown. Our results demonstrate that delaying insect access to carrion significantly lowered blowfly larvae abundances, while it simultaneously had no effect on colonization and carrion burial by burying beetles. Higher abundances of blowfly larvae seem to deter necrophagous beetles, whereas they are not harmful to the larvae of flesh flies, at least in larger rat carcasses. Predatory beetle species preferred the lower abundances of blowfly larvae, presumably due to better accessibility of their prey. Our results therefore suggest that in the course of the entire season, larvae of blowflies are the dominant competitors in small carcasses, and significantly affect the assembly of other insect groups, whereas burying beetles may exhibit a more temporal pattern of dominance.     

Territorial ants delay carrion decomposition by depressing Diptera larvae in a Tibetan alpine meadow

1. Invertebrates contribute largely to the decomposition of animal carcasses in natural ecosystems. However, we currently lack experimental evidence for the impact of predatory ants on carrion decomposition. Provided that many ant species display their role in the necrophilous community as predators but not as decomposers, we hypothesized that the ants would negatively affect the carrion decomposition rates by predating on other insect decomposers. 2. In a Tibetan alpine meadow, we conducted a one-factor designed field experiment involving three treatments, that is, 20, 60, and 500 cm of yak (Bos grunniens) carrion plots away from anthills (Camponotus herculeanus), which mirrored the high, intermediate, and low ant abundance, respectively. 3. Our results show that the necrophilous community assemblage differed significantly along the distance gradients from anthills, with the dominance of the necrophilous community shifting from ants in the 20 cm treatment to maggots in the 500 cm treatment. The ants significantly decreased the number of maggots through predation, resulting in a significant decrease of the carrion decomposition rates. However, ants did not change the number of other scavengers albeit they attacked them. 4. These results suggest that the predatory ant C. herculeanus can modify the carrion decomposition rates through generating a strong consumptive effect on decomposers, which is important to understand the necrophilous community assemblage and the decomposition of animal-based materials.     

Species Traits Predict Assemblage Dynamics at Ephemeral Resource Patches Created by Carrion

Carrion is an ephemeral and spatially patchy resource that supports a diverse subset of species linked to nutrient cycling and the decomposition process. A number of studies have separately documented changes in the diversity of plants, arthropods and vertebrates at individual carcasses, but there are few studies that have examined how functional traits of different groups of organisms underpin their responses to carrion patches. We used a carrion addition experiment to compare changes in composition and functional traits of insect and plant assemblages at carcasses compared with control sites. We found that significant changes in insect assemblage evenness and heterogeneity was associated with species’ dispersal traits, and that plant assemblage responses to subsequent soil nitrogen changes was most apparent among graminoids and exotic species. Beetles at carcasses were twice as large as their counterparts at control sites during the first week of carrion decomposition, and also had higher wing loadings. Plants with high specific leaf area responded faster to the carcass addition, and twice as many species recolonised the centre of carcasses in exotic-dominated grassland compared with carcasses in native-dominated grassland. These results provide an example of how traits of opportunist species enable them to exploit patchy and dynamic resources. This increases our understanding of how carcasses can drive biodiversity dynamics, and has implications for the way carrion might be managed in ecosystems, such as appropriate consideration of spatial and temporal continuity in carrion resources to promote heterogeneity in nutrient cycling and species diversity within landscapes.     

Decomposition rate of carrion is dependent on composition not abundance of the assemblages of insect scavengers

Environmental factors and biodiversity affect ecosystem processes. As environmental change modifies also biodiversity it is unclear whether direct effects of environmental factors on ecosystem processes are more important than indirect effects mediated by changes in biodiversity. High-quality resources like carrion occur as heterogeneous pulses of energy and nutrients. Consequently, the distribution of scavenging insects is related to resource availability. Therefore, carrion decomposition represents a suitable process from which to unravel direct effects of environmental change from indirect biodiversity-related effects on ecosystem processes. During three field seasons in 2010 we exposed traps baited with small-mammal carrion at 21 sites along a temperature gradient to explore the insect carrion fauna and decomposition rate in the Bohemian Forest, Germany. The abundance component of beetle and fly assemblages decreased with decreasing temperature. Independently, the composition component of both taxa changed with temperature and season. The change in the composition component of beetles depicted a loss of larger species at higher temperatures. Decomposition rate did not change directly along the temperature gradient but was directly influenced by season. The composition component of beetles, and to a small extent of flies, but not their abundance component, directly affected carrion decomposition. Consequently, lower decomposition rates at lower temperatures can be explained by the absence of larger beetle species. Thus, we predict that future environmental change will modify carrion fauna composition and thereby indirectly decomposition rate. Moreover, reorganizations of the insect carrion composition will directly translate into modified decomposition rates, with potential consequences for nutrient availability and carbon storage.     

Flowering phenology, floral traits and pollinator composition in a herbaceous Mediterranean plant community

The relationships between flowering plants and their insect visitors were studied in a Mediterranean grassland in north-east Spain. Floral traits (size, shape, symmetry, and colour), floral rewards (pollen and nectar), flowering period, and floral visitors were recorded for the 17 most abundant plants in the community. Flowering was year-round, but most species flowered in spring. The three species that flowered after spring had small flowers, but the distribution of floral features (including rewards offered) did not show a strong seasonality. Ants contributed 58.5% to the flower visits recorded. Other frequent visitors were beetles (12%), flies (9.5%), honey bees (6.4%), wild bees (6.4%), and wasps (5.2%). Honey bees were most abundant in April, wild bees from April to July, beetles from May to July, and ants from May to September. The lack of tight plant-insect associations was the rule, with most plant species visited by a rather diverse array of insects representing two or more orders. The plant species having narrower spectra of visitors either had flower rewards exposed or attracted mostly illegitimate visitors. By means of correspondence analysis four categories of plants were defined according to their main groups of visitors: (1) honey bees and large wild bees; (2) large wild bees; (3) ants and beetles; and (4) beetles and small-sized bees. The Mantel test was used to calculate correlations among four matrices representing similarities in visitors attracted, floral morphological traits, pollen-nectar rewards, and blooming time, respectively. In spite of seasonality shown by the different insect groups, results indicate that the observed patterns of visitor distribution among plants were most affected by pollen-nectar rewards. Received: 28 May 1996 / Accepted: 19 October 1996     

Study of community assembly patterns and interspecific interactions involved in insect succession on rat carcasses

Although many forensic entomological studies have described patterns of carrion insect succession and theoretical studies have explained interspecific interactions that drive succession, empirical studies on the quantitative and ecological aspects of carrion insect succession, such as the degree of historical contingency in community assembly and interspecific interactions during succession, are limited. In this study, I investigated variability in the successional pathways of carrion insect communities in rat carcasses and their decomposition processes, and examined the interspecific interactions involved in succession, such as the effects of carcass utilization by early‐arriving species on late‐arriving species. Members of the families Calliphoridae and Formicidae and the species Eusilpha japonica (Motschulsky) and Nicrophorus concolor Kraatz were chiefly observed. In almost all carcasses, formicid species arrived first, and calliphorid species and E. japonica arrived simultaneously or immediately after. Nicrophorus concolor arrived last, with its time of colonization occurring earlier in carcasses with greater E. japonica abundance. Meanwhile, the early‐arriving species decreased when N. concolor arrived. Nicrophorus concolor tended to reproduce on carcasses with lower cumulative abundance of early‐arriving species and tended to feed on carcasses with greater cumulative abundance of early‐arriving species. These results show that the successional pathways of the chief carrion insect species are highly consistent among carcasses. In contrast, early‐arriving species seem to influence the utilization patterns of carcasses by late‐arriving species, and therefore produce variability in the decomposition process. These results also show that succession could be driven by facilitation and interspecific competition between early‐arriving and late‐arriving species.     

The role of carrion-frequenting arthropods in the decay process

Abstract. 1. The various groups of arthropods associated with rodent carrion during decay in temperate woodland and grassland habitats are described in each of four seasons.
2. A distinction is drawn between those occurring by chance and those positively associated with the carrion.
3. The role of these last in actually assisting the decay of the carcasses with which they are found is discussed. Despite the abundance and diversity of carrion-frequenting species, few are involved to any significant extent in the release of carrion materials during decomposition.     

Contrasting diversity dynamics of phoretic mites and beetles associated with vertebrate carrion

Carrion is an ephemeral and nutrient-rich resource that attracts a diverse array of arthropods as it decomposes. Carrion-associated mites often disperse between animal carcasses using phoresy, the transport of one species by another. Yet few studies have contrasted the dynamics of mite assemblages with other insect taxa present at carrion. We examined and compared the changes in abundance, species richness and composition of mite and beetle assemblages sampled at kangaroo carcasses in a grassy eucalypt woodland at four different times over a 6-month period. We found that the majority of mites were phoretic, with the mesostigmatid genera Uroseius (Uropodidae), Macrocheles (Macrochelidae) and Parasitus (Parasitidae) the most abundant taxa (excluding astigmatid mites). Abundance and richness patterns of mites and beetles were very different, with mites reaching peak abundance and richness at weeks 6 and 12, and beetles at weeks 1 and 6. Both mites and beetles showed clear successional patterns via changes in species presence and relative abundance. Our study shows that mesostigmatid mite assemblages have a delay in peak abundance and richness relative to beetle assemblages. This suggests that differences in dispersal and reproductive traits of arthropods may contribute to the contrasting diversity dynamics of carrion arthropod communities, and further highlights the role of carrion as a driver of diversity and heterogeneity in ecosystems.     

Nesting strategies and disease risk in necrophagous beetles

While the effects of carcass decomposition on microorganisms have been demonstrated in recent years, little is known of how this impacts necrophagous insects. A common assumption is that insects that exploit carcasses are exposed to a high density of potentially harmful microorganisms, but no field data have so far validated this. Necrophagous beetles such as the Scarabaeinae have complex nesting behaviors with elaborate parental care. So here, we begin to explore whether this conjunction of life history and nesting behavior represents an adaptive response to the threat posed by microbes in these environments, mainly by entomopathogens. We evaluated the density and distribution of fungi and bacteria from soil near the carcasses, and their ability to infect and kill insects that are in contact with this soil during the decomposition process. Our data showed an increase in the density and activity of opportunistic or facultative pathogens during the apex of decomposition, when there is a predominance of necrophagous insects. Meanwhile, the survivorship of bait insects decreased when in contact with soil from this period of decomposition, indicating a potential risk of infection. However, the density and activity of these microorganisms decreased with distance from the carcass, mainly with depth, which would benefit tunneller beetles in particular. We have thus provided the first field data to show that necrophagous insects are indeed exposed to high densities of potentially harmful microorganisms. Furthermore, we propose that some parental care strategies may have arisen not only as a response to competition, but also as adaptations that reduce the risks of disease. Although we have focused on carrion feeders, we suggest that the same occurs with coprophagous beetles, as both carrion and dung are nutrient‐rich resources.     

Effects of carrion decomposition on litter arthropod assemblages

1. Many organisms contribute to the decomposition of carrion. For arthropods, many studies focus on the necrophagous community, those directly consuming carrion.
2. Necrophagous arthropods use carrion as a shelter or food source. Therefore, carrion generally increases the abundance and biodiversity of necrophagous species. However, it is unclear if carrion has similar effects on detrital communities.
3. This study examines changes in community structure and composition of necrophilous and detrital communities over the course of decomposition.
4. Five pig head carrion were placed at least 7 m apart under cages in temperate mixed forest. Leaf litter was sampled 0 m, 1.5 m, and 3 m from each carrion weekly during summer, and monthly during autumn, until the first frost. Arthropods were extracted from leaf litter by using Berlese funnels.
5. At the carrion site, necrophagous insects increased in abundance, species richness, and Shannon diversity during decomposition, and all decreased after dry decay.
6. Detritus arthropods displayed a sharp increase in abundance during advanced decay, decreasing during dry decay, and a general increase over time for species richness and diversity.
7. In conclusion, carrion can influence the surrounding, non-necrophagous arthropod community, highlighting the need to investigate carrion effects beyond typical necrophagous species to have a more holistic understanding of carrion ecology.

     

Fate of mouse carcasses in a Northern Woodland

1. Small, vertebrate carrion is a significant input into terrestrial ecosystems. The relative importance of different recyclers of carrion is poorly understood because of seasonal and habitat variation and methodological differences among studies. Many studies, in particular, do not account adequately for the activity of burying beetles (Nicrophorus spp.). 2. The present work, utilising a previously unstudied woodland, addresses this concern by: placing only two carcasses in the field at one time, using microsites only once, and providing a means to easily recover successful burying beetles. 3. Burying beetles buried 77.5% of experimental mouse carcasses over their breeding season, and typically did so within three activity periods after placement (30 of 31 burials). 4. The results and a brief review suggest that burying beetles are the dominant summer competitor for small, vertebrate carrion in mid‐ and northern latitude woodlands. Information on the age of carcasses utilised by burying beetles also provides an ecological context for laboratory studies of behaviour, life history, and microbial interactions.     

Insect biodiversity meets ecosystem function: differential effects of habitat and insects on carrion decomposition

1. Ecological processes are maintained in different environments by different species performing similar functional roles. Yet, little is known about the role of the environment in shaping insect biodiversity associated with a process that is ephemeral and patchy. 2. In this study, the mass loss of carrion in response to contrasting habitat types (grassland or tree) was quantified experimentally, as well as the presence, diversity and composition of insect assemblages. Differences in insect assemblages between these two habitats were also examined. 3. It was found that the presence of insects led to a doubling in mass loss, but that grassland or tree habitat type had no effect on this process. By contrast, habitat type had a significant effect on the composition of generalist ant and beetle assemblages, but not on specialist fly assemblages. Given the colonisation of insects, carrion mass loss was negatively associated with increasing evenness of fly assemblages and increasing ant abundance. Variation in fly assemblage composition was also found to correlate with variation in carrion mass loss. 4. This study highlights the major role of habitat type in shaping the composition of generalist insects at carrion, but the minor role in affecting specialist and highly vagile insects. This complements the authors' findings that insect colonisation of carrion was critical to accelerated mass loss, and that fly assemblages were responsible for variation in this process, regardless of habitat. The present study sheds new light on the contribution of insect biodiversity to decomposition in variable environments, with consequences for carrion food webs and nutrient cycling.     

Juvenile hormone regulates extreme mandible growth in male stag beetles

The morphological diversity of insects is one of the most striking phenomena in biology. Evolutionary modifications to the relative sizes of body parts, including the evolution of traits with exaggerated proportions, are responsible for a vast range of body forms. Remarkable examples of an insect trait with exaggerated proportions are the mandibular weapons of stag beetles. Male stag beetles possess extremely enlarged mandibles which they use in combat with rival males over females. As with other sexually selected traits, stag beetle mandibles vary widely in size among males, and this variable growth results from differential larval nutrition. However, the mechanisms responsible for coupling nutrition with growth of stag beetle mandibles (or indeed any insect structure) remain largely unknown. Here, we demonstrate that during the development of male stag beetles (Cyclommatus metallifer), juvenile hormone (JH) titers are correlated with the extreme growth of an exaggerated weapon of sexual selection. We then investigate the putative role of JH in the development of the nutritionally-dependent, phenotypically plastic mandibles, by increasing hemolymph titers of JH with application of the JH analog fenoxycarb during larval and prepupal developmental periods. Increased JH signaling during the early prepupal period increased the proportional size of body parts, and this was especially pronounced in male mandibles, enhancing the exaggerated size of this trait. The direction of this response is consistent with the measured JH titers during this same period. Combined, our results support a role for JH in the nutrition-dependent regulation of extreme mandible growth in this species. In addition, they illuminate mechanisms underlying the evolution of trait proportion, the most salient feature of the evolutionary diversification of the insects.     

Ivermectin residues in cattle dung impair insect-mediated dung removal but not organic matter decomposition

1. Veterinary parasiticide residues in livestock dung have been repeatedly shown to negatively affect the abundance and diversity of dung-associated insects. While these losses are concerning from a conservation perspective, they can also translate to impairment of ecosystem functions in agricultural landscapes (e.g. nutrient cycling, primary productivity and greenhouse gas mitigation). 2. Most research focusing on decomposition-related ecosystem functioning has focused on dung beetles (Coleoptera: Scarabaeoidea) while other insects, particularly flies, have received comparatively less attention. 3. Using mesocosms, this study manipulated the insect groups colonising cow dung (beetles only, flies only, beetles and flies together, and an insect-free control). Half of the insects were exposed to 1 mg kg⁻¹ ivermectin in dung, while the other half were exposed to ivermectin-free dung. Dung decomposition (mass of organic matter lost) and dung removal (change in the dry mass of the dung pat attributed to both dung decomposition and burial) were measured. 4. Comparison of beetles and flies in ivermectin-free dung showed that beetles removed nearly twice as much dung as did flies. Comparison of dung removal across all treatments showed that ivermectin residues significantly reduced dung removal provided by beetles by 47% and dung removal provided by beetles and flies together by 32%. 5. Organic matter decomposition was not significantly affected by insect colonists or by the presence of ivermectin, indicating that organic matter decomposition can occur independently of insect activity and chemical perturbations.     

Do Eucalyptus plantations host an insect community similar to remnant Eucalyptus forest?

Abstract We examined the potential of forest plantations to support communities of forest‐using insects when planted into an area with greatly reduced native forest cover. We surveyed the insect fauna of Eucalyptus globulus (Myrtaceae) plantations and native Eucalyptus marginata dominated remnant woodland in south‐western Australia, comparing edge to interior habitats, and plantations surrounded by a pastoral matrix to plantations adjacent to native remnants. We also surveyed insects in open pasture. Analyses focused on three major insect orders: Coleoptera, Lepidoptera and Hymenoptera. Plantations were found to support many forest‐using insect species, but the fauna had an overall composition that was distinct from the remnant forest. The pasture fauna had more in common with plantations than forest remnants. Insect communities of plantations were different from native forest both because fewer insect species were present, and because they had a few more abundant insect species. Some of the dominant species in plantations were known forestry pests. One pest species (Gonipterus scutellatus) was also very abundant in remnant forest, although it was only recently first recorded in Western Australia. It may be that plantation forestry provided an ecological bridge that facilitated invasion of the native forest by this nonendemic pest species. Plantation communities had more leaf‐feeding moths and beetles than remnant forests. Plantations also had fewer ants, bees, evanioid wasps and predatory canopy beetles than remnants, but predatory beetles were more common in the understory of plantations than remnants. Use of broad spectrum insecticides in plantations might limit the ability of these natural enemies to regulate herbivore populations. There were only weak indications of differences in composition of the fauna at habitat edges and no consistent differences between the fauna of plantations adjacent to remnant vegetation and those surrounded by agriculture, suggesting that there is little scope for managing biodiversity outcomes by choosing different edge to interior ratios or by locating plantations near or far from remnants.     

Ground Beetle (Coleoptera: Carabidae) Assemblages of Restored Semi‐natural Habitats and Intensively Cultivated Fields in Northern China

Diversity of ground beetle (Coleoptera: Carabidae) assemblages and sub‐assemblages was compared between reafforested woodland, grassland, and intensively cultivated fields at Chongli County in Northern China. An array of eight pitfall traps per plot was used to sample the beetles on four replicate plots for each habitat. Replanted conifer woodland and semi‐natural grassland harbored very similar beetle assemblages. These had significantly lower rarefied species numbers than the distinctly different assemblages recorded in cultivated fields, with differences in alpha diversity being less pronounced for large and predatory species. Carabid activity‐density levels were higher in both woodland and grassland than in fields, with this trend being most pronounced for predatory and large species. To conserve high levels of gamma diversity, it is important to maintain a mosaic of agricultural areas and semi‐natural habitats. The latter also form a potential source for predatory species important in pest control. It appears that woodland‐specific species are rare in the study area, or they have not been able to reach and colonize the newly established woodland sites. It can also be concluded that morphological and ecological traits allow important insights into underlying ecological principles of overall diversity patterns.     

Paleoecological and Taphonomic Implications of Insect-Damaged Pleistocene Vertebrate Remains from Rancho La Brea,Southern California

The La Brea Tar Pits, the world’s richest and most important Late Pleistocene fossil locality, offers unsurpassed insights into southern California’s past environments. Recent studies at Rancho La Brea document that insects serve as sensitive and valuable paleoecological and taphonomic indicators. Of the thousands of fossil bird and mammal bones recovered from the Tar Pits, insect trace damage is thus far almost exclusively confined to the foot bones of large herbivores, especially bison, camel, and horse species. Our laboratory experiments with dermestid and tenebrionid beetles establish that the larvae of both consume bone, producing different characteristic feeding traces and providing the first documentation that tenebrionids consume bone. The presence of carcass-exploiting insects in the Rancho La Brea biota provides insight into the taphonomy of the asphaltic bone masses and the environmental conditions under which they accumulated. The succession of dermestids, tenebrionids, and indeterminate traces on many of the foot elements, combined with the climate restrictions and life cycles of these insects, indicate that carcasses could remain unsubmerged for at least 17–20 weeks, thus providing the most reliable estimate to date. Attribution of these traces also suggests that the asphaltic fossils only accumulated during warmer intervals of the Late Pleistocene. Forensic studies need to reevaluate the role of tenebrionids in carcass decomposition and other additional insects that modify bone.     

Transition from wind pollination to insect pollination in sedges: experimental evidence and functional traits

Transitions from wind pollination to insect pollination were pivotal to the radiation of land plants, yet only a handful are known and the trait shifts required are poorly understood. We tested the hypothesis that a transition to insect pollination took place in the ancestrally wind-pollinated sedges (Cyperaceae) and that floral traits modified during this transition have functional significance. We paired putatively insect-pollinated Cyperus obtusiflorus and Cyperus sphaerocephalus with related, co-flowering, co-occurring wind-pollinated species, and compared pairs in terms of pollination mode and functional roles of floral traits. Experimentally excluding insects reduced seed set by 56-89% in putatively insect-pollinated species but not in intermingled wind-pollinated species. The pollen of putatively insect-pollinated species was less motile in a wind tunnel than that of wind-pollinated species. Bees, beetles and flies preferred inflorescences, and color-matched white or yellow models, of putatively insect-pollinated species over inflorescences, or color-matched brown models, of wind-pollinated species. Floral scents of putatively insect-pollinated species were chemically consistent with those of other insect-pollinated plants, and attracted pollinators; wind-pollinated species were unscented. These results show that a transition from wind pollination to insect pollination occurred in sedges and shed new light on the function of traits involved in this important transition.     

Carrion mimicry in a South African orchid: flowers attract a narrow subset of the fly assemblage on animal carcasses

BACKGROUND AND AIMS: Although pollination of plants that attract flies by resembling their carrion brood and food sites has been reported in several angiosperm families, there has been very little work done on the level of specificity in carrion mimicry systems and the importance of plant cues in mediating such specialization. Specificity may be expected, as carrion-frequenting flies often exploit different niches, which has been interpreted as avoidance of interspecific competition. Interactions between the orchid Satyrium pumilum and a local assemblage of carrion flies were investigated, and the functional significance of floral traits, especially scent, tested. Pollination success and the incidence of pollinator-mediated self-pollination were measured and these were compared with values for orchids with sexual- and food-deceptive pollination systems. METHODS AND KEY RESULTS: Observations of insect visitation to animal carcasses and to flowers showed that the local assemblage of carrion flies was dominated by blow flies (Calliphoridae), house flies (Muscidae) and flesh flies (Sarcophagidae), but flowers of the orchid were pollinated exclusively by flesh flies, with a strong bias towards females that sometimes deposited live larvae on flowers. A trend towards similar partitioning of fly taxa was found in an experiment that tested the effect of large versus small carrion quantities on fly attraction. GC-MS analysis showed that floral scent is dominated by oligosulfides, 2-heptanone, p-cresol and indole, compounds that also dominate carrion scent. Flesh flies did not distinguish between floral and carrion scent in a choice experiment using olfactory cues only, which also showed that scent alone is responsible for fly attraction. Pollination success was relatively high (31·5 % of flowers), but tracking of stained pollinia also revealed that a relatively high percentage (46 %) of pollen deposited on stigmas originates from the same plant. CONCLUSIONS: Satyrium pumilum selectively attracts flesh flies, probably because its relatively weak scent resembles that of the small carrion on which these flies predominate. In this way, the plants exploit a specific subset of the insect assemblage associated with carrion. Pollination rates and levels of self-pollination were high compared with those in other deceptive orchids and it is therefore unlikely that this mimicry system evolved to promote outcrossing.     

Summary of the morphological and ecological traits of Central European dung beetles

Ecological, morphological and life‐history traits have been increasingly used in community ecology during the last decade. Dung beetles represent a model group of insects frequently used in studies of landscape ecology and grassland management. Their body sizes and nesting behavioral traits are regularly used to help understand ecological processes at the community level. However, information on their seasonal activity, wing morphometry and dung specialization is sparse in published reports, or is simply not available yet. We thus compiled a comprehensive list of the morphological and ecological traits of Central European dung beetles (Geotrupidae, Scarabaeidae and Aphodiidae). We gathered information from published works and, for the first time, took morphometric measurements of wings. We provide a database of 12 traits for all 100 dung beetle species occurring in Central Europe. Most species are not restricted to one specific dung type, and the most frequently used dung types are sheep/goat, cattle and horse dung, which are almost equally exploited by 90, 89 and 87 species, respectively. More than one‐third of all species are active in winter, and the number of active species is the highest in June. The wing morphometry shows a high variation and is largely determined by the family identity; the ratio of elytron length to wing area is the largest in Aphodiidae but the smallest in Geotrupidae. Our database is the first standardized set of information for Central European dung beetles and can be used in future trait‐based studies focusing on the ecology and conservation of these beetles.