Dung beetles increase plant growth: a meta-analysis.

The ecosystem services provided by dung beetles are well known and valued. Dung beetles bury dung for feeding and breeding, and it is generally thought that the process of burying dung increases nutrient uptake by plant roots, which promotes plant growth. Many studies have tested the effects of dung beetles on plant growth, but there has been no quantitative synthesis of these studies. Here we use a multi-level meta-analysis to estimate the average effect of dung beetles on plant growth and investigate factors that moderate this effect. We identified 28 publications that investigated dung beetle effects on plant growth. Of these, 24 contained the minimum quantitative data necessary to include in a meta-analysis. Overall, we found that dung beetles increased plant growth by 17%; the 95% CI for possible values for the true increase in plant growth that were most compatible with our data, given our statistical model, ranged from 1% to 35%. We found evidence that the dung beetle-plant growth relationship is influenced by the plant measurement type and the number of beetles accessing the dung. However, beetles did not increase plant growth in all quantitative trials, as individual effect sizes ranged from -72% to 806%, suggesting important context-dependence in the provision of ecosystem services.

Macroecology of Dung Beetles in Italy.

The Italian fauna includes about 170 species/subspecies of dung beetles, being one of the richest in Europe. We used data on dung beetle distribution in the Italian regions to investigate some macroecological patterns. Specifically, we tested if species richness decreased southward (peninsula effect) or northward (latitudinal gradient). We also considered the effects of area (i.e., the species-area relationship), topographic complexity, and climate in explaining dung beetle richness. Finally, we used multivariate techniques to identify biotic relationships between regions. We found no support for the peninsula effect, whereas scarabaeines followed a latitudinal gradient, thus supporting a possible role of southern areas as Pleistocene refuges for this group of mainly thermophilic beetles. By contrast, aphodiines were more associated with cold and humid climates and do not show a distinct latitudinal pattern. In general, species richness was influenced by area, with the Sardinian fauna being however strongly impoverished because of its isolation. Faunal patterns for mainland regions reflect the influence of current ecological settings and historical factors (Pleistocene glaciations) in determining species distributions.

Species-specific larval acoustic behaviour of three stag beetles (Coleoptera: Lucanidae), with emphasis on their stridulatory organs and acoustic signals.

Acoustic behaviour plays a significant role in insect communications, but is rarely reported in their immature stages. Larvae of Lucanidae bear paired stridulatory organs on their thoracic legs, which could produce sounds as communicational signals. However, the species-specific differences on stridulatory organs and acoustic signals are far from fully investigated. In this study, the larval acoustic behaviours of three lucanid species, Lucanus dybowski, Prosopocoilus confucius and P. girafa were recorded and compared for the first time. The sound producing mechanism was described in detail based on video recordings, morphological observations, and acoustic analyses. The larvae of all three species are able to produce sounds by scraping the plectrum on the metatrochanter against the pars stridens on the mesocoxa during disturbance. The sounds exhibit species-specific differences in terms of acoustic parameters: the larvae of L. dybowski produce short-duration (140-200 ms), single-pulse and low-frequency (∼210 Hz) sounds; P. confucius produce long-duration (500-800 ms), triple-pulse and low-frequency (∼280 Hz) sounds; P. girafa produce long-duration (500-560 ms), double-pulse and low-frequency (∼260 Hz) sounds. The amounts and arrangements of the teeth on stridulatory organs also exhibit differences on specific level. The acoustic signals and stridulatory organs were compared using principal component analysis.

Entyposisfrici (Coleoptera, Scarabaeidae, Melolonthinae), a new species from Somaliland.

Entyposisfrici Bezdek & Sehnal, sp. nov., from Somaliland is described and relevant diagnostic characters are illustrated. The new species is compared with the morphologically closely similar Entyposis Kolbe, 1894 species. An updated checklist and an identification key to northeastern African Entyposis species are provided.

A trait-based framework for dung beetle functional ecology.

Traits are key for understanding the environmental responses and ecological roles of organisms. Trait approaches to functional ecology are well established for plants, whereas consistent frameworks for animal groups are less developed. Here we suggest a framework for the study of the functional ecology of animals from a trait-based response-effect approach, using dung beetles as model system. Dung beetles are a key group of decomposers that are important for many ecosystem processes. The lack of a trait-based framework tailored to this group has limited the use of traits in dung beetle functional ecology. We review which dung beetle traits respond to the environment and affect ecosystem processes, covering the wide range of spatial, temporal and biological scales at which they are involved. Dung beetles show trait-based responses to variation in temperature, water, soil properties, trophic resources, light, vegetation structure, competition, predation and parasitism. Dung beetles' influence on ecosystem processes includes trait-mediated effects on nutrient cycling, bioturbation, plant growth, seed dispersal, other dung-based organisms and parasite transmission, as well as some cases of pollination and predation. We identify 66 dung beetle traits that are either response or effect traits, or both, pertaining to six main categories: morphology, feeding, reproduction, physiology, activity and movement. Several traits pertain to more than one category, in particular dung relocation behaviour during nesting or feeding. We also identify 136 trait-response and 77 trait-effect relationships in dung beetles. No response to environmental stressors nor effect over ecological processes were related with traits of a single category. This highlights the interrelationship between the traits shaping body-plans, the multi-functionality of traits, and their role linking responses to the environment and effects on the ecosystem. Despite current developments in dung beetle functional ecology, many knowledge gaps remain, and there are biases towards certain traits, functions, taxonomic groups and regions. Our framework provides the foundations for the thorough development of trait-based dung beetle ecology. It also serves as an example framework for other taxa.

Links Between Feeding Preferences and Electroantennogram Response Profiles in Dung Beetles: The Importance of Dung Odor Bouquets.

The detection of dung odors is a crucial step in the food-searching behavior of dung beetles (Coleoptera: Scarabaeoidea). Yet, whether certain compounds characteristic of a given dung type contribute to a 'choosy generalism' behavior proposed for this taxonomic group is unknown. To address this, we analyzed the chemical composition of three types of dung (cow, horse, and rabbit) and conducted behavioral and electroantennogram (EAG) bioassays on 15 species of dung beetles using 19 volatile organic compounds representing the three dung samples. Chemical analyses revealed substantial qualitative and quantitative differences among dung types. When offered these food options in an olfactometer, 14 species exhibited a feeding preference. Surprisingly, all 19 compounds used in the EAG assays elicited antennal responses, with species displaying different olfactory profiles. The relationship between behavioral preferences and electrophysiological profiles highlighted that species with different food preferences had differences in antennal responses. Moreover, a specific set of EAG-active compounds (nonanal, sabinene, acetophenone, ρ-cresol, 2-heptanone, 1H-indole, and 6-methyl-5-hepten-2-one) were the strongest drivers in the distinct sensory profiles of the trophic preference groups. Our results point to the importance of the whole bouquet of dung-emanating compounds in driving food-searching behavior, but specific volatiles could aid in determining highly marked trophic preferences in certain species.

A contribution to the genus Didrepanephorus Wood-Mason, 1878 (Coleoptera, Scarabaeidae, Rutelinae).

The diagnostic characters of the genera Didrepanephorus Wood-Mason, 1878 and Fruhstorferia Kolbe, 1894 are clarified. The following nomenclatorial acts are proposed: Didrepanephorusbirmanicus (Arrow, 1907), comb. nov., Didrepanephorusfukinukii (Muramoto & Araya, 2000), comb. nov., Fruhstorferiabaron (Prokofiev, 2013), comb. nov., and Fruhstorferiaanthracina Ohaus, 1903, comb. rev. Didrepanephorustangzhaoyangi Zhao & Liu, sp. nov. is described from Yunnan Province, China. A lectotype is designated for Fruhstorferiabirmanica Arrow, 1907. Didrepanephorusmizunumai Nagai & Hirasawa, 1991 is reported from Myanmar for the first time.

Seasonality and bait type driving the diversity of dung beetle (Scarabaeidae: Scarabaeinae) communities in urban remnants of the Atlantic Forest

ABSTRACT Describing dung beetle communities in tropical forest remnants located in disturbed/urbanized and conserved areas can provide information about the functioning of these ecosystems and support conservation plans. This study aimed to verify the effect of seasons and bait type on dung beetle communities in remnants of the Atlantic Forest in order to describe their composition and diversity parameters. The study was carried out during both the rainy and dry seasons in periurban and urban remnants. Eighteen pitfall traps baited with feces, carrion, and injured millipedes were established in each site. A total of 3501 individuals and 23 species were recorded. Urban remnant presented higher abundance of individuals in the dry season. On the other hand, in periurban remnant the higher abundance was verified in the rainy season. The diversity was higher in the rainy season in both sites. In urban remnant, Coprophanaeus ensifer was found to be generalist regarding its choice of bait (feces and carrion). The use of injured millipedes as bait allowed the record of the predatory species Deltochilum alpercata. Among the types of bait used, the injured millipedes proved to be very effective, capturing a greater diversity of dung beetles during the rainy season in both remnants, and allowed the collection of specialized, necrophages, and generalists species. Therefore, we propose the use of mixed-bait sampling designs in inventories and surveys to increase the chances of sampling species with different traits or dietary preferences, which are often rare in collections.

Dung Beetle Assemblages Attracted to Cow and Horse Dung: The Importance of Mouthpart Traits, Body Size, and Nesting Behavior in the Community Assembly Process.

Dung beetles use excrement for feeding and reproductive purposes. Although they use a range of dung types, there have been several reports of dung beetles showing a preference for certain feces. However, exactly what determines dung preference in dung beetles remains controversial. In the present study, we investigated differences in dung beetle communities attracted to horse or cow dung from a functional diversity standpoint. Specifically, by examining 18 functional traits, we sought to understand if the dung beetle assembly process is mediated by particular traits in different dung types. Species specific dung preferences were recorded for eight species, two of which prefer horse dung and six of which prefer cow dung. Significant differences were found between the functional traits of the mouthparts of the dung beetles attracted to horse dung and those that were attracted to cow dung. Specifically, zygum development and the percentage of the molar area and the conjunctive area differed between horse and cow dung colonizing beetles. We propose that the quantitative differences in the mouthpart traits of the species attracted to horse and cow dung respectively could be related to the differential capacity of the beetles to filtrate and concentrate small particles from the dung. Hence, the dung preference of dung beetles could be related to their ability to exploit a specific dung type, which varies according to their mouthpart traits. Moreover, we found that larger and nester beetles preferred cow dung, whereas smaller and non-nester beetles preferred horse dung. This finding could be related to the tradeoff between fitness and parental investments, and to the suitability of the trophic resource according to the season and species phenology.

Diversity Patterns of Dung Beetles along a Mediterranean Elevational Gradient.

Most studies of biodiversity-elevational patterns do not take species abundance into consideration. Hill numbers are a unified family of indices that use species abundance and allow a complete characterization of species assemblages through diversity profiles. Studies on dung beetle responses to elevation were essentially based on species richness and produced inconsistent results because of the non-distinction between different habitats and the use of gradients dispersed over wide areas. We analyzed dung beetle diversity in a Mediterranean mountain (central Italy) for different habitats (woodlands vs. grasslands) and taxonomic groups (scarabaeids and aphodiids). Scarabaeids were the most abundant. Since scarabaeids are able to construct subterranean nests, this indicates that the warm and dry summer climatic conditions of high elevations favor species capable of protecting their larvae from desiccation. Dung beetles were more abundant and diversified in grasslands than in woodlands, which is consistent with their preference for open habitats. In the woodlands, diversity increased with increasing elevation because of increasing tree thinning, whereas, in the grasslands, diversity decreased with elevation because of increasingly harsher environmental conditions. These results indicate a trade-off in the beetle response to elevation between the positive effects of increasing the availability of more suitable habitats and the decrease of optimal environmental conditions.

Dung beetles as samplers of mammals in Malaysian Borneo-a test of high throughput metabarcoding of iDNA.

Invertebrate-derived DNA (iDNA) sampling in biodiversity surveys is becoming increasingly widespread, with most terrestrial studies relying on DNA derived from the gut contents of blood-feeding invertebrates, such as leeches and mosquitoes. Dung beetles (superfamily Scarabaeoidea) primarily feed on the faecal matter of terrestrial vertebrates and offer several potential benefits over blood-feeding invertebrates as samplers of vertebrate DNA. Importantly, these beetles can be easily captured in large numbers using simple, inexpensive baited traps, are globally distributed, and occur in a wide range of habitats. To build on the few existing studies demonstrating the potential of dung beetles as sources of mammalian DNA, we subjected the large-bodied, Bornean dung beetle (Catharsius renaudpauliani) to a controlled feeding experiment. We analysed DNA from gut contents at different times after feeding using qPCR techniques. Here, we first describe the window of DNA persistence within a dung beetle digestive tract. We found that the ability to successfully amplify cattle DNA decayed over relatively short time periods, with DNA copy number decreasing by two orders of magnitude in just 6 h. In addition, we sampled communities of dung beetles from a lowland tropical rainforest in Sabah, Malaysia, in order to test whether it is possible to identify vertebrate sequences from dung beetle iDNA. We sequenced both the gut contents from large dung beetle species, as well as whole communities of smaller beetles. We successfully identified six mammalian species from our samples, including the bearded pig (Sus barbatus) and the sambar deer (Rusa unicolor)-both vulnerable species on the IUCN red list. Our results represent the first use of dung beetle iDNA to sample Southeast Asian vertebrate fauna, and highlight the potential for dung beetle iDNA to be used in future biodiversity monitoring surveys.

Seasonal variation in the diel activity of a dung beetle assemblage.

The seasonal and diel variations of dung beetle species were studied in an Iberian mid-mountain locality to examine the interaction between these two temporal rhythms. We assume that a seasonal variation in the diel activity would support the notion that both rhythms may assist in achieving a quick and flexible response when the climatic conditions change. Data coming from 4,104 pitfall traps placed during 15 sampling periods and totalling 30 daily sampling cycles were analysed using circular statistics and General Linear Models. A wide variety of seasonal patterns are observed, highlighting those species with a clear unimodal or spring-autumn bimodal seasonal pattern. However, a midday diel pattern is the norm in most of the species, except in the case of those exhibiting a high body weight that prefer dusk or night periods. We hypothesize that most of the dung beetle species fly at noon to promote the passive heating of their muscle activity and minimize the metabolic energy expenditure. Results only partially support the seasonal variation in diel activity. Diel preferences are mainly manifested at the time of the year in which the abundance is greater. Approximately two-thirds of the considered species exhibit a similar diel activity along their seasonal active period. As consequence, a significant portion of the dung beetle species currently inhabiting Mediterranean mid-mountains are not able to use the daily variation in climatic conditions to limit the inconveniences of climate change.

Navigation and orientation in Coleoptera: a review of strategies and mechanisms.

Spatial orientation is important for animals to forage, mate, migrate, and escape certain threats, and can require simple to complex cognitive abilities and behaviours. As these behaviours are more difficult to experimentally test in vertebrates, considerable research has focussed on investigating spatial orientation in insects. However, the majority of insect spatial orientation research tends to focus on a few taxa of interest, especially social insects. Beetles present an interesting insect group to study in this respect, due to their diverse taxonomy and biology, and prevalence as agricultural pests. In this article, I review research on beetle spatial orientation. Then, I use this synthesis to discuss mechanisms beetles employ in the context of different behaviours that require orientation or navigation. I conclude by discussing two future avenues for behavioural research on this topic, which could lead to more robust conclusions on how species in this diverse order are able to traverse through a wide variety of environments.

Description of the male of emPterorthochaetes/em emyunnanensis/em Ballerio, 2014 (Coleoptera: Scarabaeoidea: Hybosoridae: Ceratocanthinae).

The ceratocanthine genus Pterorthochaetes Gestro, 1898 (Coleoptera: Scarabaeoidea: Hybosoridae) includes about 26 valid species and occurs from the eastern Himalaya (Nepal and India) and southern China to northern Australia (Queensland) and Vanuatu Islands (Paulian 1978, 1987; Ballerio 1999, 2006, 2013, 2014).

emSphaeraphodius/em emgaohani/em, a new genus and species of Aphodiini (Coleoptera: Scarabaeidae: Aphodiinae) from Guangxi, China.

Sphaeraphodius gaohani Kakizoe, Jiang Wang, a new genus and new species of the tribe Aphodiini, is described based on two female specimens from Guangxi, China. This new genus differs considerably from any previously known genera of Aphodiini by dorsally swollen body covered by considerably long setae, and lack of transverse setiferous carinae on outer surfaces of meso- and metatibiae. This new taxon is found sympatrically with the termite Macrotermes sp. in the field. Therefore, this species is perhaps termitophilous, but we cannot conclude it at this time due to the insufficient information available in the field.

A new species and a new country record in the genus emProtaetia/em Burmeister, 1842 (Coleoptera: Scarabaeidae: Cetoniinae) from Vietnam.

Protaetia (Macroliocola) dianae Mückstein, a new species of fruit chafer (Coleoptera: Scarabaeidae: Cetoniinae) from northern Vietnam is described. Habitus and diagnostic features of the new species are illustrated. A new country record of Protaetia (Liocola) miharai (Alexis Delpont, 1998) for Vietnam is presented.

Two new species of the genus Bolboceras/ Kirby, 1819 (Coleoptera: Bolboceratidae: Bolboceratinae) from India with an updated identification key of the Bolboceras nigricans/ Westwood, 1848 species group.

Bolboceras bopdevense Kalawate Hillert, new species and Bolboceras trimbakense Kalawate Hillert, new species, both classified in the Bolboceras nigricans Westwood, 1848 species group are described from India. Illustrations and comparison with known members of the B. nigricans species group are given. The new described species are included in an updated identification key of the species group. Finally, known localities of this species group are mapped. For the Oriental and east Palearctic regions, all known localities of the genus Bolboceras Kirby, 1819 are listed, and associated coordinates are given.

Bolbelasmus (Bolbelasmus) zagrosensis (Coleoptera: Scarabaeoidea: Bolboceratidae), a new species from Iran, along with an updated key to the western Palaearctic species of the subgenus.

Bolbelasmus (Bolbelasmus) zagrosensis Sommer, Hillert, Hruzová Král, new species, from Iran is described, illustrated and compared with its congeners known from the western Palaearctic region. An updated key to the western Palaearctic species of the nominotypical subgenus is provided. New country record of B. (B.) nireus (Reitter, 1895) from Greece (island of Rhodes) is reported. Distribution of B. (B.) makrisi Miessen, 2011, B. (B.) nireus and the new species is summarized and mapped.

Proper cleaning of keratin beetles reveals a cryptic species: Phoberus fumarius (Haaf, 1953) from southern Africa is reinstated as valid (Coleoptera: Trogidae).

Among the southern African Trogidae, Trox fumarius Haaf, 1953 is presently considered a junior subjective synonym of Phoberus cyrtus (Haaf, 1953). The availability of more specimens than were seen by previous workers, coupled with thorough removal of cuticular dirt and accumulated debris, allowed in-depth morphological study of these nominal taxa and reassessment of their synonymy. Consistent differences in external morphology and in aedeagal structure are observed. Trox fumarius is removed from synonymy with Phoberus cyrtus, reinstated as a separate species, and transferred to the genus Phoberus MacLeay, 1819. Both species are diagnosed and redescribed. Photographs of their holotypes and of cleaned specimens illustrate them. The distributions of these two putatively sister species are discussed along with their probable habitat associations. The species are allopatric and have non-overlapping associations with biomes and habitats. Phoberus cyrtus is reported from Botswana for the first time. The importance of properly cleaning terricolous beetles covered with dirt and debris that obscure taxonomic features is emphasised and guidelines to achieve this are presented.

Identification and description of the antennal sensilla of Liogenys suturalis (Coleoptera: Scarabaeidae)

ABSTRACT Species of the scarab beetle genus Liogenys are potential pests to several crops in Brazil. This study aimed to describe the antennal sensilla of Liogenys suturalis (Blanchard, 1851). Adults were collected in a pasture area in Bálsamo, São Paulo state, Brazil, using a light trap. The antennae were dissected and images of the antennal sensilla were obtained using a scanning electron microscope. Sensilla ampulacea (pores), s. auricilica, s. basiconica, s. placodea, and s. trichodea are present in the lamellae. The antenna of females have 4399 sensilla, of which 3671 (83.5%) are s. placodea, 422 (9.5%) s. coeloconica, and 306 (6.9%) s. auricilica. The antennae of males have 4039 sensilla, of which 3117 (77.1%) are s. placodea, 353 (8.7%) s. coeloconica, and 569 (14.1%) s. auricilica. The antennal sensilla of the genus Liogenys have been described for the first time.