Nesting of Afrotropical Oniticellus (Coleoptera, Scarabaeidae) and its evolutionary trend from soil to dung

Abstract. 1. Oniticellus egregius Klug constructs brood ovoids of dung in the soil immediately under the edge of animal droppings. Each successive brood ovoid is enveloped within a soil shell. After completion of brood construction, loose earth is cleared from around the broods to produce a brood chamber. The immatures are then abandoned as eggs or first instar larvae.
2. O.planatus Castelnau and O.formosus Chevrolat usually construct brood balls of dung within animal droppings. Each brood is progressively enlarged by the addition of further dung after egg-laying. This enlargement is slight in O.planatus and marked in O.formosus. Parental females of both species remain in the brood chambers during development of the immatures which are abandoned principally as pupae.
3. Under very moist experimental conditions, O.planatus buries dung and constructs broods shallowly in the soil. Such nests are frequently connected to the pad by a short tunnel.
4. From a consideration of behavioural patterns it is suggested that the specialized nesting habits of these species have been derived from those of dung-burying ancestors similar to the modern genus, Euoniticellus, through reduction and loss of tunnelling in the soil.     

Changes in ground beetle diversity and community composition in age structured forests (Coleoptera, Carabidae)

We examined diversity, community composition, and wing-state of Carabidae as a function of forest age in Piedmont North Carolina. Carabidae were collected monthly from 396 pitfall traps (12×33 sites) from March 2009 through February 2010, representing 5 forest age classes approximately 0, 10, 50, 85, and 150 years old. A total of 2,568 individuals, representing 30 genera and 63 species, were collected. Carabid species diversity, as estimated by six diversity indices, was significantly different between the oldest and youngest forest age classes for four of the six indices. Most carabid species were habitat generalists, occurring in all or most of the forest age classes. Carabid species composition varied across forest age classes. Seventeen carabid species were identified as potential candidates for ecological indicators of forest age. Non-metric multidimensional scaling (NMDS) showed separation among forest age classes in terms of carabid beetle community composition. The proportion of individuals capable of flight decreased significantly with forest age.     

Asymmetric competition in cattle dung between two species of Onthophagus dung beetle and the bush fly, Musca vetustissima

Abstract.

• 1 Competition in cattle dung pads between two dung beetles, Onthophagus ferox Harold and Onthophagus binodis Thunberg, and the bush fly, Musca vetustissima Walker, was investigated in laboratory experiments, to determine why spring fly abundance in the field did not fall following the introduction of O. binodis.
• 2 At low beetle densities, the number of eggs laid by each species was reduced by the second species. A similar amount of dung was buried by each species alone or by both together.
• 3 At high beetle densities O. binodis egg production was substantially affected by each additional O.ferox, but O.ferox egg production was not affected by each additional O.binodis. Asymmetric competition occurred because O.ferox buried more dung than O.binodis, and a greater proportion in day 1 (pre-emptive dung burial).
• 4 O.ferox caused greater M. vetustissima egg-puparia mortality than O. binodis. Mortality mostly occurred in young M. vetustissima larvae less than 1 day old. Total egg-puparia fly mortality was correlated better with the dung buried on day 1 than dung buried on day 8 (pre-emptive dung burial). O.binodis did not add to fly mortality by O.ferox at high densities because of asymmetric competition between the beetles.

     

Seasonal distribution and prevalence of dung beetles (Coleoptera: Scarabaeidae) in Kurukshetra,Northern India

A total of 8306 individuals as 29 species from 3 subfamilies (Hybosorinae, Aphodiinae, Scarabaeinae) were trapped by pitfall bait trapping. The maximum number of species of Scarabaeinae (68.97%) and number of individuals of Aphodiinae (56.84%) take part in the formation of a community. The number of species, number of individuals, diversity and dominance changes throughout the season. Seasonal prevalence of 82.76% of species and 50.81% of individuals was found in June. Aphodius campestris was found to be more attracted to the pitfall bait traps. The beetle community found in May shows the maximum Shannon's Diversity Index (2.46) but Margalef's Diversity Index was highest in August (3.06). Environmental factors play an important role in the occurrence and abundance of dung beetles. In the present study non-significant but positive correlations between temperature and species richness, abundance and diversity were found. Percent relative humidity showed a positive correlation with abundance only, and negative correlations with species richness and diversity.     

Between-group differences in the Iberian dung beetle species-area relationship (Coleoptera: Scarabaeidae)

Between-group α- and β-diversity differences were derived from species-area relationships fitted to field data. The accuracy of spatial richness variation predictions based on area size was also checked. The log-log model (log S = c + z log A) was found to be the best-fit linear model, with slopes (z) ranging from 0.089 to 0.142. Between-group comparisons of z (slope) and q (intercept) parameters, using the S = q + cA^z curvilinear regression model, corroborated early results, indicating a lower β-diversity (slope) for Scarabaeinae than for Geotrupinae and Aphodiinae. The latter group, probably more sensitive to environmental heterogeneity, should contribute more to species richness in large areas. α-Diversity is greater for Aphodiinae, more relevant to local diversity (1 km²), than for Scarabaeinae and considerably greater for these two groups than for Geotrupinae. As earlier results show that the richness of a single dung pat is rather more a function of the Scarabaeinae species pool, richness on dung pat scales is probably due more to the between-dropping mobile Scarabaeinae, while Aphodiinae contribute mainly to local and regional pool richness. Nearly 88 % of the total richness variance is explained by area size. This percentage decreases to 37 % when the spatial structure of area size and species number are extracted. The corresponding figures for Scarabaeinae, Aphodiinae and Geotrupinae are 44, 22 and 31 %, respectively.     

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.

     

松嫩草地牛粪中大型节肢动物种类组成及种群动态变化

研究并分析了松嫩草地牛粪中大型节肢动物种类组成及动态变化.结果表明,在草地牛粪中共调查到大型节肢动物7目20科43种,以鞘翅目、膜翅目和双翅目为主.依其食性不同,分为粪食性型(8科19种)、腐食性型(4科4种)、植食性型(4科6种)、捕食性型(5科11种)、杂食性型(2科5种)、尸食性型(1科1种)和寄生性型(1科1种).根据鞘翅目金龟总科中营粪食性型生活的粪甲虫对牛粪利用方式的不同,分为外生粪甲虫(6种)、内生粪甲虫(5种)、远生粪甲虫(2种)和偷窃寄生粪甲虫(1种).除了双顶嗡蜣螂,牛粪中大型节肢动物数量与鲜牛粪重量具有显著正相关关系(p＜0.01).粪食性型种类数和个体数量随鲜牛粪堆置时间的延长而迅速减少,7d后消失,其个体总数量与鲜牛粪堆积时间呈显著的负相关关系(p＜0.01),而与牛粪含水量呈显著正相关关系(p＜0.01),各种大型节肢动物因其食性不同在鲜牛粪中占据不同的生态位.鲜牛粪中大型节肢动物以粪食性型占绝对优势,而干牛粪中则以捕食性型和杂食性型为主.牛粪中大型节肢动物种群季节动态变化受温度、降水量与牛粪含水量影响,鲜牛粪中大型节肢动物优势种为直蜉金龟(69.25%)和肖秋家蝇与东方角蝇幼虫(25.12%).4、5、6月份和9月份,优势种为直蜉金龟,7月和8月份,优势种为蝇幼虫.     

Duration and benefits of biparental brood care in the dung beetle Onthophagus vacca (Coleoptera: Scarabaeidae)

Abstract.

• 1 Single males, single females or pairs of dung beetles, Onthophagus vacca, were released on artificial small (100 g) or large (1000 g) dung pats in the laboratory. Emigrating beetles were trapped at 12 h intervals, and the number and size of the brood chambers were recorded after each replicate.
• 2 Emigration of males was delayed if females were present in the same dung pats, whereas emigration times of females were independent of the presence or absence of males.
• 3 A residency of 60 h proved to be a threshold value. Females emigrating before this time did not breed, whereas those emigrating later had built at least two brood chambers.
• 4 Females paired with males built more brood chambers than single females.
• 5 The reproductive success of pairs was not influenced by the size of the dung pats.

     

Food availability controls the onset of metamorphosis in the dung beetle Onthophagus taurus (Coleoptera: Scarabaeidae)

In nature, larvae of the dung beetle Onthophagus taurus (Schreber 1759) are confronted with significant variation in the availability of food without the option of locating new resources. Here we explore how variation in feeding conditions during the final larval instar affects larval growth and the timing of pupation. We found that larvae respond to food deprivation with a reduction in the length of the instar and premature pupation, leading to the early eclosion of a small adult. To achieve pupation, larvae required access to food for at least the first 5 days of the final instar (= 30% of mean third‐instar duration in control individuals), and had to exceed a weight of 0.08 g (= 58% of mean peak weight in control individuals). Larvae that were allowed to feed longer exhibited higher pupation success, but increased larval weight at the time of food deprivation did not result in increased pupation success except for larvae weighing > 0.14 g. Larvae responded to food deprivation by initiating and undergoing the same sequence of developmental events, requiring the same amount of time, as ad libitum‐fed larvae once those had reached their natural peak weight. Our results reveal a striking degree of flexibility in the dynamics and timing of larval development in O. taurus. They also suggest that premature exhaustion of a larva's food supply can serve as a cue for the initiation of metamorphosis. Premature metamorphosis in response to food deprivation has been documented in amphibians, but this is, to the best of our knowledge, the first time such a behaviour has been documented for a holometabolous insect. We discuss our findings in the context of the natural history and behavioural ecology of onthophagine beetles.     

Genetic diversity of the dung beetle,Copris tripartitus (Coleoptera: Scarabaeidae), that is endangered in Korea

The dung beetle, Copris tripartitus (Coleoptera: Scarabaeidae), is an endangered insect in Korea. In order to establish a conservation strategy, a preliminary investigation on the genetic diversity of Korean populations was performed using mitochondrial COI (658 bp), CytB (433 bp), and nuclear ITS2 (411 nucleotide positions). Sequencing of 69 individuals collected from five localities showed substantially higher variability (5.02% for COI, 4.62% for CytB, and 8.03% for ITS2). The resulting networks for mitochondrial DNA (mtDNA) haplotypes exhibited two star‐like phylogenies, which might indicate that Korean populations have recently expended from two small populations. The ITS2 network, which was presented in the form of a star‐like phylogeny, confirmed that a recent population expansion occurred. Considering the high genetic diversity and gene flow in C. tripartitus populations, one issue regarding conservation seems to be the recovery of previous habitats.     

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.     

Experimental warming alters the relative survival and emigration of two dung beetle species from an Australian dung pat community

To preserve insect‐mediated ecosystem services under ongoing climate change, it is necessary to first understand the impact that warming will have on the insects that provide or mediate these services. Furthermore, because responses of a species may be modified by interactions with competitors, it is informative to examine warming effects on organisms and service provision under competition. Dung beetles provide numerous services to agriculture by burying the manure of other animals. To understand the potential impacts of climate warming on ecosystem service provision, we exposed two dung beetle species (Sisyphus rubrus and Euoniticellus fulvus (Coleoptera: Scarabaeidae)), occurring together in the same experimental pats, to warming and measured reproduction (dung ball production and burial, brood production, and egg laying), pat departure behaviour and survival of both species. These two species are likely competitors in pastures in northern New South Wales. To simulate climate warming, we used custom‐built chambers to add offsets (+0, +2 or +4°C) to field recorded, diurnally fluctuating baseline temperatures. There was no direct effect of increased temperature on any measured trait in either species. We did find however that the relative survival of the two species depended on temperature; S. rubrus had a higher probability (resulting in greater odds) of surviving than E. fulvus in the +0 and +4°C offset chambers, but not in the +2°C offset chambers. Likewise, the relative likelihood of the different species leaving a dung pat was temperature dependent; in the +2°C offset chambers, E. fulvus were more likely to leave than S. rubrus, but not in the +0 and +4°C offsets chambers. Our results highlight that it may be important for future studies to consider warming effects on relative survival and emigration because such effects could potentially lead to changes in dung beetle species composition.     

粪甲虫对绢蒿荒漠春秋两季牛粪分解的影响

为明确绢蒿荒漠草地牛粪的分解规律,分别在5月(春季)和9月(秋季)设置不同堆置时间点(0、7、29、48、58 h),明确粪便理化性质变化规律,同时设置不同开口的网笼(无网笼、上下开口、上开口、全封口),探讨各生态功能类群粪甲虫对粪便分解的影响.结果表明:春季的粪甲虫种类数显著高于秋季,秋季的粪甲虫数量显著高于春季.春...     

Genetic divergence between the South Korean and Mongolian populations of the dung beetle,Gymnopleurus mopsus (Coleoptera: Scarabaeidae) based on mitochondrial cytochrome c oxidase subunit I (COI) gene sequences

The locally extinct dung beetle, Gymnopleurus mopsus Pallas, 1781 (Coleoptera: Scarabaeidae), has not been found in South Korea since the 1970s. This research was conducted to understand the genetic divergence between the South Korean and Mongolian populations of G. mopsus as a part of its reintroduction program in South Korea. The genetic distance and diversity were determined using the mitochondrial cytochrome c oxidase subunit I (COI) gene sequence (658 bp ) corresponding to the DNA barcode region. The mitochondrial COI gene sequences of 64 individuals of G. mopsus collected in South Korea (7 individuals) and Mongolia (57 individuals) showed a relatively high level of genetic diversity (nucleotide diversity, 0.0078 ± 0.0007; Haplotype diversity, 0.965 ± 0.017). The genetic distances between the South Korean and Mongolian populations lay within the intraspecific level and the phylogenetic reconstruction using the neighbor‐joining (NJ) method showed that all individuals belonged to a single clade. This result indicates that the current Mongolian population of G. mopsus is a good candidate source population to restore the locally extinct population of the species in South Korea.     

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.