Dung beetles provide a variety of ecosystem services in both natural and farmed landscapes. Amongst these services, reductions in the abundance of the free-living stages of pests and parasites that ...develop in faeces is considered to be of great importance. There is evidence from Australia that enhanced dung beetle populations can reduce populations of pest fly species, particularly the bush fly, however, there is little empirical evidence for reductions in the incidence and impact of nematode parasitism in grazing ruminants. There are two main pathways whereby beetles can disrupt worm life-cycles: predaceous species that feed on eggs or larvae can directly reduce populations in dung whereas coprophagous species can affect parasite development, survival and translocation by altering the location, microclimate and infrastructure of dung deposits. In addition, predaceous mites that are phoretic on dung beetles, can also prey on larval stages in the faeces. To date, reductions in both larval survival and the acquisition of gastrointestinal nematode burdens in ruminants on pasture has been reported only in association with the activity of large tunnelers that bury dung 15 cm or more below ground. The activity of dwellers, rollers and shallow tunnelers can either limit or enhance larval development and translocation, depending on the influence of other factors, notably rainfall. Currently, the scientific evidence for dung beetles playing a major role in the control of gastrointestinal nematodes in domestic ruminants is very limited and may have been overestimated in assessments of their ecosystem services.
•Dung beetle activity can impact parasitic nematode epidemiology.•Beetles burying dung ≥15 cm can reduce pasture larval populations.•Shallowly buried and fragmented dung affect larval survival inconsistently.•Little evidence that beetles affect coccidial, cestode or trematode epidemiology.
In livestock management systems, the rapid removal of cattle dung by dung beetles plays an essential role in returning areas of pasture to grazing which normally would be lost because of dung ...contamination. Thus, dung removal is an ecosystem process with established links to services with potentially valuable outcomes. We focused on dung removal under two dung beetle abundance scenarios. We then calculated the economic value of dung beetle action on dung degradation in US sub-tropical pasturelands under each scenario by measuring the costs associated with restriction of new forage growth by dung pat smothering, and the amount of forage gained because of dung beetle mediated dung decomposition. We found if dung is left unmanipulated by dung beetles, it would naturally decompose at an average rate of 3.75 g per day, and dung in pastures with a high abundance of dung beetles would decay at 10.73 g per day. We show the economic benefit of dung decomposition under each scenario is directly related to both the presence and abundance levels of dung beetles in cattle pastures, for instance, resulting in additional grass area to become available to raise 1,131 cows and 1,676 cows under low dung beetle abundances and under high dung beetle abundances, respectively. This amounts to an additional income of USD 918,688 per year in Florida sub-tropical livestock systems containing low abundances of dung beetles and an income of USD 1,360,770 per year for pastures sustaining a higher abundances of dung beetles. Despite their importance in livestock systems dung beetle populations are imperiled by the widespread use of agrochemicals. Reducing agrochemical usage and introducing biodiversity-friendly practices in livestock systems will be important for conserving dung beetles and the ecological functions that dung beetles provide in working landscapes.
Dung beetles can influence seedling emergence and survival. However, the direction and magnitude of this effect will depend on the functional traits of the dung beetle community and on the prevailing ...environmental conditions. We studied the role of dung beetles in seed dispersal of Prosopis flexuosa DC. in an arid environment. We conducted an experimental study to assess how different dung beetle species differ in their effectiveness as secondary seed dispersers. To evaluate this question, we selected four species belonging to three functional groups: lifters, tunnelers, and rollers. Dung beetles removed 0.7%-7.5% of the seeds embedded in cow dung. The net effect of beetles on seedling emergence and survival varied markedly among species: Malagoniella puncticollis (roller) had neutral effects on seedling emergence and positive in their survival. Sulcophanaeus imperator, Digitonthophagus gazella (tunneler) and Eucranium arachnoides (lifters) species had positive effect on seedling emergence. However, the effect of S. imperator on seedling survival was negative, and those of D. gazella and E. arachnoides, neutral. Our results indicate that although dung beetles remove few seeds of P. flexuosa, their main role consisted in producing changes in micro-environmental conditions for the seeds that remained in the dung pile. Photos: Luciana Quiroga (A), Diego N. Mirás (B and C), Belén Maldonado (D)
Dung beetles (Genus: Onthophagus) are members of the family Scarabaeidae and the subfamily Scarabaeinae. Despite their small size and unattractive appearance, dung beetles play an important role in ...the ecosystem, and they are widely recognised as one of the most effective bioindicators of ecosystem health. Although there has been an increase in dung beetle studies in Peninsular Malaysia, there are very few ecological studies of dung beetles conducted in Sarawak, despite being the largest state of Malaysia. Therefore, this study aims to provide recent information on the distributions of dung beetles from the genus Onthophagus in Sarawak. A total of 32 occurrences data for eight selected Onthophagus species representing 11 localities were successfully recorded. All analyses were performed using the Maximum Entropy Modelling Version 3.4.4 (MaxEnt) and Quantum Geographic Information Systems 3.28.2 (QGIS) software. It is revealed that most dung beetles’ distributions are strongly influenced by temperature and precipitation which suggests its capabilities as a bioindicator to identify high biodiversity areas. In conclusion, this study could be beneficial to identify the potential hotspot areas for biodiversity conservation and effective management practices in Sarawak.
New Insect Host Defense Peptides Transcriptomes Ramirez, German Alberto Tellez; Osorio-Mendez, Juan Felipe; Arias, Diana Carolina Henao ...
Journal of insect science (Tucson, Ariz.),
07/2021, Letnik:
21, Številka:
4
Journal Article
Recenzirano
The Coleoptera Scarabaeidae family is one of the most diverse groups of insects on the planet, which live in complex microbiological environments. Their immune systems have evolved diverse families ...of Host Defense Peptides (HDP) with strong antimicrobial and immunomodulatory activities. However, there are several peptide sequences that await discovery in this group of organisms. This would pave the way to identify molecules with promising therapeutic potential. This work retrieved two sources of information: 1) De-novo transcriptomic data from two species of neotropical Scarabaeidae (Dichotomius satanas and Ontophagus curvicornis); 2) Sequence data deposited in available databases. A Blast-based search was conducted against the transcriptomes with a subset of sequences representative of the HDP This work reports 155 novel HDP sequences identified in nine transcriptomes from seven species of Coleoptera: D. satanas (n = 76; 49.03%), O. curvicornis (n = 23; 14.83%), (Trypoxylus dichotomus) (n = 18; 11.61%), (Onthophagus nigriventris) (n = 10; 6.45%), (Heterochefus sp) (n = 6; 3.87%), (Oxysternon conspicillatum) (n = 18; 11.61%), and (Popillia japonica) (n = 4; 2.58%). These sequences were identified based on similarity to known HDP insect families. New members of defensins (n = 58; 37.42%), cecropins (n = 18; 11.61%), attancins (n = 41; 26.45%), and coleoptericins (n = 38; 24.52%) were described based on their physicochemical and structural characteristics, as well as their sequence relationship to other insect HDPs. Therefore, the Scarabaeidae family is a complex and rich group of insects with a great diversity of antimicrobial peptides with potential antimicrobial activity. Key words: antimicrobial cationic peptide, insect protein, computational biology, cecropin, defensin
New Insect Host Defense Peptides Ramirez, German Alberto Tellez; Osorio-Mendez, Juan Felipe; Arias, Diana Carolina Henao ...
Journal of insect science (Tucson, Ariz.),
07/2021, Letnik:
21, Številka:
4
Journal Article
Recenzirano
The Coleoptera Scarabaeidae family is one of the most diverse groups of insects on the planet, which live in complex microbiological environments. Their immune systems have evolved diverse families ...of Host Defense Peptides (HDP) with strong antimicrobial and immunomodulatory activities. However, there are several peptide sequences that await discovery in this group of organisms. This would pave the way to identify molecules with promising therapeutic potential. This work retrieved two sources of information: 1) De-novo transcriptomic data from two species of neotropical Scarabaeidae (Dichotomius satanas and Ontophagus curvicornis); 2) Sequence data deposited in available databases. A Blast-based search was conducted against the transcriptomes with a subset of sequences representative of the HDP This work reports 155 novel HDP sequences identified in nine transcriptomes from seven species of Coleoptera: D. satanas (n = 76; 49.03%), O. curvicornis (n = 23; 14.83%), (Trypoxylus dichotomus) (n = 18; 11.61%), (Onthophagus nigriventris) (n = 10; 6.45%), (Heterochefus sp) (n = 6; 3.87%), (Oxysternon conspicillatum) (n = 18; 11.61%), and (Popillia japonica) (n = 4; 2.58%). These sequences were identified based on similarity to known HDP insect families. New members of defensins (n = 58; 37.42%), cecropins (n = 18; 11.61%), attancins (n = 41; 26.45%), and coleoptericins (n = 38; 24.52%) were described based on their physicochemical and structural characteristics, as well as their sequence relationship to other insect HDPs. Therefore, the Scarabaeidae family is a complex and rich group of insects with a great diversity of antimicrobial peptides with potential antimicrobial activity.
Dung beetles are holometabolous insects that feed on herbivorous mammal dung and provide services to the ecosystem including nutrient cycling and soil fertilization. It has been suggested that ...organisms developing on incomplete diets such as dungs require the association with microorganisms for the synthesis and utilization of nutrients. We describe the diversity and composition of the gut-microbiota during the life cycle of the dung beetle Copris incertus using 16S rRNA gene sequencing. We found that C. incertus gut contained a broad diversity of bacterial groups (1,699 OTUs and 302 genera). The taxonomic composition varied during the beetle life cycle, with the predominance of some bacterial genera in a specific developmental stage (Mothers: Enterobacter and Serratia; Eggs: Nocardioides and Hydrogenophaga; Larval and pupal stages: Dysgonomonas and Parabacteroides; offspring: Ochrobactrum). The beta diversity evidenced similarities among developmental stages, clustering (i) the adult stages (mother, male and female offsprings), (ii) intermediate developmental (larvae and pupa), and (iii) initial stage (egg). Microbiota differences could be attributed to dietary specialization or/and morpho-physiological factors involved in the transition from a developmental stage to the next. The predicted functional profile (PICRUSt2 analysis) for the development bacterial core of the level 3 categories, indicated grouping by developmental stage. Only 36 categories were significant in the SIMPER analysis, including the metabolic categories of amino acids and antibiotic synthesis, which were enriched in the larval and pupal stages; both categories are involved in the metamorphosis process. At the gene level, we found significant differences only in the KOs encoding functions related to nitrogen fixation, uric acid metabolism, and plant cell wall degradation for all developmental stages. Nitrogen fixation and plant cell wall degradation were enriched in the intermediate stages and uric acid metabolism was enriched in mothers. The data reported here suggested the influence of the maternal microbiota in the composition and diversity of the gut microbiota of the offspring.
•Biological control is an underutilised tool for controlling parasitic nematodes.•In-feed treatment with nematophagous fungi can reduce larval numbers post-excretion.•The fungus Duddingtonia flagrans ...is the first commercial biological control agent.•Dung beetles and earthworms can help to reduce infective stages on pasture.•Integrated parasite management facilitates sustainable parasite control.
Gastrointestinal nematodes (GIN) are a cause of significant losses in animal production worldwide. In recent years, there have been important advances in the biological control of GIN of ruminants and horses. While these measures are still relatively under-utilised in practice, interest will undoubtedly grow due to the emergence of drug resistant parasite populations, the rise in demand for organically farmed products (which does not allow prophylactic use of drugs, including anthelmintics) and legislation, which regulates and restricts the use of anthelmintics. This review provides an overview of the most promising biocontrol agents of GIN of grazing animals including nematophagous fungi, dung beetles, earthworms, predacious nematodes and nematophagous mites. Recent advancements in these fields are evaluated, and the potential reasons for the delayed development and slow uptake of biocontrol agents are discussed. It is now widely believed that no method of GIN control is sustainable alone, and a combination of strategies (i.e. integrated pest management) is required for long term, effective parasite control. This review shows that, although their efficacies are lower than those of conventional anthelmintics, biological control agents are an important adjunct to traditional GIN control.
The dung beetle Phelotrupes auratus is a holometabolous insect belonging to the order Coleoptera, and it is widely distributed in Japan. The P. auratus habitat depends on herbivores. P. auratus eats ...the dung of the herbivores and carries it underground for its young. In this process, herbivore droppings disappear from the ground, not only keeping the ground hygienic but also maintaining good soil conditions for plant growth. In this way, a rich ecosystem is maintained. In recent years, the population of P. auratus has decreased, and the main cause has been the decrease in grazing land. It seems that Japanese dung beetles are mainly dependent on herbivores for nutrient sources. However, the physiological relationship between herbivores and P. auratus has not been well investigated. Here, we investigated the nutritional metabolism system of P. auratus by performing whole gene expression analysis of individuals collected from two areas where the ecosystem is occupied by different herbivores. We obtained 54,635 transcripts from P. auratus from Nara Park and Cape Toi and identified 2,592 differentially expressed genes in the fat bodies of the Nara Park and Cape Toi groups. We annotated P. auratus transcripts using Homo sapiens and Drosophila melanogaster genes as references; 50.5% of P. auratus transcripts were assigned to H. sapiens genes, and 54.0% of P. auratus transcripts were assigned to D. melanogaster genes. To perform gene set enrichment analysis, we chose H. sapiens genes for P. auratus transcript annotation. Principal component analysis and gene set enrichment analysis revealed that the nutritional metabolism of P. auratus from Cape Toi might differ from that of P. auratus from Nara Park. We analyzed the nutritional metabolism system of P. auratus from Cape Toi and Nara Park and found that the characteristics of the nutritional metabolism process might depend on the plants consumed by the herbivores. Our findings will contribute to elucidating the relationships among habitat plants, herbivores, and dung decomposers and may aid in the maintenance of sustainable land health cycles.
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