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)
Anthelmintic residues in livestock dung can adversely affect beneficial organisms. Targeted selective treatment (TST) of a reduced proportion of livestock with anthelmintics can slow resistance ...development in gastrointestinal nematodes by providing residue-free dung which could also benefit non-target organisms. We tested effects of TST on survival and reproduction of the dung beetle Onthophagus taurus (Scarabaeidae) in a factorial glasshouse experiment (Experimental treatments: five TST levels, 0.00, 0.25, 0.50, 0.75, 1.00 x four ivermectin concentrations, 125, 250, 375, 500 ppb). Each mesocosm comprised a 60 L bin containing sand, four dung pats and six pairs of adult beetles (F0 generation). No effects of TST level and ivermectin concentration on mortality of F0 adults after one week were observed. F0 adult brood ball production was affected by TST level, particularly at high ivermectin concentrations. Brood ball production increased as more untreated pats became available, with greater increases at higher ivermectin concentrations. We tested for evidence of a reported attraction of dung beetles to ivermectin-treated dung using a novel glitter-marker to trace the origin of dung used in brood balls. Where mesocosms contained both dung types, the proportion of brood balls created from untreated dung showed no statistical difference from the null expectation based on untreated dung availability in the mesocosm. Emergence of F1 adults was affected by the increase in TST, with this effect dependent on concentration. Treatments with concentrations of 250–500 ppb had the lowest emergence rates (ca. 5–20 % in mesocosms where all dung pats were treated) but emergence rates increased with TST level, reaching 68–88 % emergence where no dung pats were treated with ivermectin. Ivermectin-induced mortality occurred predominantly at egg and first instar stages. TST can provide refuges for dung beetles offering a strategy for livestock producers to maintain livestock welfare whilst benefiting from ecosystem services provided by important insects.
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•Anthelmintics control livestock nematode pests, but harm beneficial dung beetles.•Targeted selective treatment (TST) could reduce non-target impacts.•Experimental TST led to more dung beetle brood balls and greater offspring survival.•Benefits of TST to dung beetles were greatest at high anthelmintic concentration.•TST has dual benefits: reduced agrichemical use and more dung beetles.
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 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.
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
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.
•We evaluate if Eucalyptus plantations are novel or hybrid ecosystems.•We compare biotic and abiotic components among the ecosystems evaluated.•Eucalyptus plantations are hybrid ecosystems.•Proper ...management of this system might improve its conservation value.•Modified ecosystems present different potential for biodiversity conservation.
Novel and hybrid ecosystems present different conservation values for native species. Therefore, the classification of modified ecosystems into a novel or hybrid state is an essential step to assist conservation strategies for biodiversity. During the last decades, plantations of Eucalyptus have increased in the highly threatened Atlantic Forest region, highlighting the importance of defining this ecosystem as novel or hybrid. In this study, we evaluated whether Eucalyptus plantations are novel or hybrid ecosystems by contrasting biotic components (dung beetle communities) and abiotic components (local environmental variables) within historical (Atlantic Forest remnants) and non-historical (pasture) environments in the Atlantic Forest biome, located in Bahia state, Brazil. Our results show that Eucalyptus plantations should be classified and managed as a hybrid ecosystem in this biome. Of the 21 dung beetle species found in Eucalyptus, ten were shared with historical forests (52.6% of Eucalyptus species) and 6 with pastures (31.5%). Eucalyptus plantations have environmental aspects similar to both historical forests and pastures. Despite presenting similar components to historical and non-historical ecosystems, Eucalyptus plantations are sufficiently distinct not to be classified as either one of them. Our results highlight the potential conservation value of Eucalyptus plantations in the Atlantic Forest region as complementary habitat for historical species, and we discuss how alternative management at landscape and stand (local) scales might increase this value. Although dung beetles are an excellent group to monitor biodiversity, we reinforce the necessity to perform further studies using another taxon that present different ecosystem requirements.
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