Objective:To investigate insects visiting sun exposed and shaded decomposing rabbit carcasses and to establish the relationship between insects and carcasses which may be of forensic importance in Harare.Methods:Two r...Objective:To investigate insects visiting sun exposed and shaded decomposing rabbit carcasses and to establish the relationship between insects and carcasses which may be of forensic importance in Harare.Methods:Two rabbits weighing 2.3 kg and 2.5 kg were killed by sharp blows on the head.One was exposed to the sun while the other was placed under shade.The carcasses were allowed to decompose and insects were collected twice a day for the first week and thereafter once a day up to the end of the 7 weeks.Maggots were also collected from the decomposing carcasses and reared.Results:Five dipteran families(Galliphoridae,Muscidae,Sarcophagidae,Phoridae and Drosophilidae)were identified from the sun-exposed carcass.Species collected included Lucilia cuprina(L.cuprina),Chrysomya albiceps(C.albiceps),Musca domestica,Sarcophaga sp.and Drosophila sp.Four families(Calliphoridae,Muscidae,Phoridae,Anthomyiidae)were identified from the shaded carcass.Representatives of these families included L cuprina,C.albiceps,Musca domestica,and Hydrotaea sp.Three Coleopteran families(Histeridae,Cleridae and Dermestidae)were identified from hodt carcasses.The observed species were Saprinus sp,Necrobia rufipes and Dermestes sp.Fomicidae(Hymenoptera)was represented by only one species(Pheidoie sp.)Flies which emerged from the rearing units were L cuprina,Lucilia sp.,C.albiceps,Sarcophaga sp.and Sepsis sp.).Conclusions:Of the dipteran species collected during the study,L cuprina and C.albiceps could be important for further forensic studies since they were collected from the carcasses and also observed from the rearing units.展开更多
Large carrion is inhabited by highly variable and interactive communities of insects.Positive interactions in carrion insect communities have been recently the focus in carrion ecology.In contrast,competition between ...Large carrion is inhabited by highly variable and interactive communities of insects.Positive interactions in carrion insect communities have been recently the focus in carrion ecology.In contrast,competition between carrion insects is rather undervalued.Here we provide evidence that blow flies(Calliphoridae)and Necrodes beetles(Silphidae),dominant decomposers of large carcasses in terrestrial habitats,compete over carrion.By reanalyzing the results from 90 pig carcasses,we demonstrated that the contribution of the flies and the beetles to the decay was negatively related.The greater part of the large carrion pool was monopolized by blow flies,whereas Necrodes beetles abundantly colonized carcasses,on which blow flies were less effective as decomposers.In behavioral assays,we found that adult beetles killed 4 times more frequently feeding than postfeeding third instar larvae of the flies,with the large decrease in the killing frequency after the larvae reached the age of early third instar.Therefore,adult Necrodes beetles preferentially killed the larvae that were before or in their peak feeding.The study provides evidence that the interaction between blow flies and Necrodes beetles is a combination of indirect exploitative effects of the flies and direct interference effects of the beetles(the mixed competition).展开更多
The gut microbiota significantly influences host physiology and provides essential ecosystem services.While diet can affect the composition of the gut microbiota,the gut microbiota can also help the host adapt to spec...The gut microbiota significantly influences host physiology and provides essential ecosystem services.While diet can affect the composition of the gut microbiota,the gut microbiota can also help the host adapt to specific dietary habits.The carrion crow(Corvus corone),an urban facultative scavenger bird,hosts an abundance of pathogens due to its scavenging behavior.Despite this,carrion crows infrequently exhibit illness,a phenomenon related to their unique physiological adaptability.At present,however,the role of the gut microbiota remains incompletely understood.In this study,we performed a comparative analysis using 16S rRNA amplicon sequencing technology to assess colonic content in carrion crows and 16 other bird species with different diets in Beijing,China.Our findings revealed that the dominant gut microbiota in carrion crows was primarily composed of Proteobacteria(75.51%)and Firmicutes(22.37%).Significant differences were observed in the relative abundance of Enterococcus faecalis among groups,highlighting its potential as a biomarker of facultative scavenging behavior in carrion crows.Subsequently,E.faecalis isolated from carrion crows was transplanted into model mice to explore the protective effects of this bacterial community against Salmonella enterica infection.Results showed that E.faecalis down-regulated the expression of pro-inflammatory cytokines tumor necrosis factor alpha(TNF-α),interferon gamma(IFN-γ),and interleukin 6(IL-6),prevented S.enterica colonization,and regulated the composition of gut microbiota in mice,thereby modulating the host’s immune regulatory capacity.Therefore,E.faecalis exerts immunoregulatory and anti-pathogenic functions in carrion crows engaged in scavenging behavior,offering a representative case of how the gut microbiota contributes to the protection of hosts with specialized diets.展开更多
Aggregations of juveniles are dominant forms of social life in some insect groups.Larval societies are shaped by competitive and cooperative interactions of the larvae,in parallel with parental effects.Colonies of nec...Aggregations of juveniles are dominant forms of social life in some insect groups.Larval societies are shaped by competitive and cooperative interactions of the larvae,in parallel with parental effects.Colonies of necrophagous larvae are excellent systems to study these relationships.Necrodes littoralis(Staphylinidae:Silphinae),a carrion beetle that colonizes cadavers of large vertebrates,forms massive juvenile aggregations.By spreading over carrion anal and oral exudates,the beetles form the feeding matrix,in which the heat is produced and by which adults presumably affect the fitness of the larvae.We predict that exploitative competition shapes the behavior of N.littoralis larvae in their aggregations.However,cooperative interactions may also operate in these systems due mainly to the benefits of collective exodigestion.Moreover,indirect parental effects(i.e.,formation of the feeding matrix)probably modulate larval interactions within the aggregations.By manipulating parental effects(present/absent)and larval density(0.02−1.9 larvae/g of meat),we found a strong negative group-size effect on fitness components of N.littoralis,in colonies with parental effects over almost the entire density range,and in colonies without parental effects for densities larger than 0.5 larva/g.This was accompanied by positive group-size effects in terms of development time(it shortened with larval density)and thermogenesis(it increased with larval density).A pronounced positive group-size effect on juvenile fitness was found only in colonies without parental effects and only in the low-density range.These results support the hypothesis that larval societies of N.littoralis are shaped by exploitation competition.展开更多
Carrion’s disease is a neglected tropical disease caused by Bartonella bacilliformis,a vector-borne pathogen restricted to the Andean valleys of Peru,Ecuador and Colombia.Carrion’s disease is a biphasic illness;in t...Carrion’s disease is a neglected tropical disease caused by Bartonella bacilliformis,a vector-borne pathogen restricted to the Andean valleys of Peru,Ecuador and Colombia.Carrion’s disease is a biphasic illness;in the acute phase the case-fatality rate can be as high as 88%,related to high parasitemia,arriving to almost all erythrocytes,and secondary bacterial infections close related with the development of transient immunosuppression in the earlier illness phases.In addition,there are an undefined number of asymptomatic carriers that are reservoirs of the etiological agent of Carrion’s disease in endemic areas,they make take into account due to they are the perpetuators of this disease.The actual scenario of Carrion’s disease,in which the illness is arriving to new areas,due to the expansion of the vector’s distribution,suggests that now may be a crucial time to design a strategy focusing on its elimination.展开更多
Proton pump inhibitors strongly inhibit gastric acid production,but digestion problems do not generally arise.We can intake almost ordinary food even after total gastrectomy.Small intestine itself can digest and absor...Proton pump inhibitors strongly inhibit gastric acid production,but digestion problems do not generally arise.We can intake almost ordinary food even after total gastrectomy.Small intestine itself can digest and absorb food using various digestive enzymes without digestion in the stomach.The pH level of gastric acid in humans is much lower than that of most animals,and very close to that of carrion-eating animals called scavengers.It is assumed that ancient humans became bipedal approximately 4 million years ago.It was difficult for humans,who just started unstable bipedal locomotion,to catch quadrupedal-walking animals that can move faster,without special hunting tools.They may have eaten remaining carcasses,which is mainly the leftovers of carnivora species,as animalderived food.The benefit to produce a volume of gastric acid for humans is carrion eating,in which disinfection by gastric acid is important.Humans produce a high concentration of gastric acid to enable consumption of a diet containing some bacteria and support this lifestyle by consuming significant energy to protect themselves from gastric acid.Now,the opportunity for strong deleterious bacteria to enter the gastrointestinal tract has decreased because of the organized clean environment.If this hygienic environment is maintained for a long time,our gastric acid level must be decreased gradually.展开更多
When female blow flies Lucilia sericata and Phormia regina （Diptera： Cal- liphoridae） oviposit in aggregations on carrion, even-aged larval offspring reportedly de- velop faster, and fewer are parasitized or preyed...When female blow flies Lucilia sericata and Phormia regina （Diptera： Cal- liphoridae） oviposit in aggregations on carrion, even-aged larval offspring reportedly de- velop faster, and fewer are parasitized or preyed upon. The benefits of aggregated ovipo- sition equally affect con- and heterospecific larvae sharing a resource. The benefits imply that female blow flies engage in coordinated, pheromone-mediated oviposition behavior. Yet, repeated attempts to identify oviposition pheromones have failed invoking doubt that they exist. Simply by regurgitating and feeding on carrion, flies may produce attractive semiochemicals. If flies were to aggregate in response to feeding flies rather than oviposit- ing flies, then the semiochemical cue（s） may be associated with the salivary gland. Working with L. sericata and P.. regina and using liver as a surrogate oviposition medium, we test the hypotheses, and present data in their support, that （i） gravid or nongravid females ovipositing and/or feeding on liver enhance its attractiveness to gravid and nongravid fe- males; （ii） females respond to semiochemicals from feeding heterospecific females; （iii） females respond equally well to semiochemicals from feeding con- and heterospecific females; （iv） macerated head tissues of females applied to liver enhance its attractiveness; and （v） females in direct contact with and feeding on liver, but not when next to yet physically separated from liver, enhance attraction of flies. We conclude that oviposition site-seeking females do not respond to an oviposition pheromone. Instead, they appear to coopt semiochemicals associated with feeding flies as resource indicators, taking chances that resources are suitable for oviposition, and that ovipositing flies are present.展开更多
Decomposition research is still in its infancy,but significant advances have occurred within forensic anthropology and other disciplines in the past several decades.Decomposition research in forensic anthropology has ...Decomposition research is still in its infancy,but significant advances have occurred within forensic anthropology and other disciplines in the past several decades.Decomposition research in forensic anthropology has primarily focused on estimating the postmortem interval(PMI),detecting clandestine remains,and interpreting the context of the scene.Additionally,while much of the work has focused on forensic-related questions,an interdisciplinary focus on the ecology of decomposition has also advanced our knowledge.The purpose of this article is to highlight some of the fundamental shifts that have occurred to advance decomposition research,such as the role of primary extrinsic factors,the application of decomposition research to the detection of clandestine remains and the estimation of the PMI in forensic anthropology casework.Future research in decomposition should focus on the collection of standardized data,the incorporation of ecological and evolutionary theory,more rigorous statistical analyses,examination of extended PMIs,greater emphasis on aquatic decomposition and interdisciplinary or transdisciplinary research,and the use of human cadavers to get forensically reliable data.展开更多
Necrophagous blowflies(Diptera:Calliphoridae)such as Calliphora vicina,a cold-tolerant species,and L ucilia serie ata,a warm-adapted species,are pioneer carrion・breeder.Although these two species have different temper...Necrophagous blowflies(Diptera:Calliphoridae)such as Calliphora vicina,a cold-tolerant species,and L ucilia serie ata,a warm-adapted species,are pioneer carrion・breeder.Although these two species have different temperature preferences,larvae aggregate actively and often feed simultaneously on carrion.The hypothesis to be tested was that L.sericata benefits from the association with C.vicina at lower temperatures(i.e.,15℃)and that C.vicina derives greater benefits from this association at higher temperatures(i.e.,28℃).Therefore,both species were raised at these two constant temperatures from first instars to adults under three different conditions:monospecific low-density,monospecific high-density,and heterospecific high-density.The time until larval migration,surface area of puparia,and survival rates were determined for each condition.Differences between these fitness-related traits were found between species,temperatures,group densities,and species compositions.At 28°C,C.vicina larvae bred in heterospecific groups migrated significantly earlier and in higher numbers than that under same density conspecific con・ditions,with a lower mortality rate.At 15°C,both species benefited from high-density heterospecific associations,expressed by faster development and larger puparia.In conclusion,necrophagous larvae benefited from heterospecific aggregations at suboptima 1 temperatures by adapting their migration time to that of the faster species.Since temperature changes throughout the day and over the year,the beneficiary of such a collective association also changes.The costs involved and deviations to the temperature-size rule highlight the complexity of the carrion ecosystem.展开更多
基金Funded by the Department of Anatomy,College of Health Sciences,University of Zimbabwe(Grant No.Jato 35)
文摘Objective:To investigate insects visiting sun exposed and shaded decomposing rabbit carcasses and to establish the relationship between insects and carcasses which may be of forensic importance in Harare.Methods:Two rabbits weighing 2.3 kg and 2.5 kg were killed by sharp blows on the head.One was exposed to the sun while the other was placed under shade.The carcasses were allowed to decompose and insects were collected twice a day for the first week and thereafter once a day up to the end of the 7 weeks.Maggots were also collected from the decomposing carcasses and reared.Results:Five dipteran families(Galliphoridae,Muscidae,Sarcophagidae,Phoridae and Drosophilidae)were identified from the sun-exposed carcass.Species collected included Lucilia cuprina(L.cuprina),Chrysomya albiceps(C.albiceps),Musca domestica,Sarcophaga sp.and Drosophila sp.Four families(Calliphoridae,Muscidae,Phoridae,Anthomyiidae)were identified from the shaded carcass.Representatives of these families included L cuprina,C.albiceps,Musca domestica,and Hydrotaea sp.Three Coleopteran families(Histeridae,Cleridae and Dermestidae)were identified from hodt carcasses.The observed species were Saprinus sp,Necrobia rufipes and Dermestes sp.Fomicidae(Hymenoptera)was represented by only one species(Pheidoie sp.)Flies which emerged from the rearing units were L cuprina,Lucilia sp.,C.albiceps,Sarcophaga sp.and Sepsis sp.).Conclusions:Of the dipteran species collected during the study,L cuprina and C.albiceps could be important for further forensic studies since they were collected from the carcasses and also observed from the rearing units.
基金The study was funded by the National Science Centre of Poland(grant no.2016/21/B/NZ8/00788).
文摘Large carrion is inhabited by highly variable and interactive communities of insects.Positive interactions in carrion insect communities have been recently the focus in carrion ecology.In contrast,competition between carrion insects is rather undervalued.Here we provide evidence that blow flies(Calliphoridae)and Necrodes beetles(Silphidae),dominant decomposers of large carcasses in terrestrial habitats,compete over carrion.By reanalyzing the results from 90 pig carcasses,we demonstrated that the contribution of the flies and the beetles to the decay was negatively related.The greater part of the large carrion pool was monopolized by blow flies,whereas Necrodes beetles abundantly colonized carcasses,on which blow flies were less effective as decomposers.In behavioral assays,we found that adult beetles killed 4 times more frequently feeding than postfeeding third instar larvae of the flies,with the large decrease in the killing frequency after the larvae reached the age of early third instar.Therefore,adult Necrodes beetles preferentially killed the larvae that were before or in their peak feeding.The study provides evidence that the interaction between blow flies and Necrodes beetles is a combination of indirect exploitative effects of the flies and direct interference effects of the beetles(the mixed competition).
基金supported by the National Key Research and Development Program of China(2022YFC2601602)Major Program of National Natural Science Foundation of China(32090023)Beijing Wildlife Rescue Center,China。
文摘The gut microbiota significantly influences host physiology and provides essential ecosystem services.While diet can affect the composition of the gut microbiota,the gut microbiota can also help the host adapt to specific dietary habits.The carrion crow(Corvus corone),an urban facultative scavenger bird,hosts an abundance of pathogens due to its scavenging behavior.Despite this,carrion crows infrequently exhibit illness,a phenomenon related to their unique physiological adaptability.At present,however,the role of the gut microbiota remains incompletely understood.In this study,we performed a comparative analysis using 16S rRNA amplicon sequencing technology to assess colonic content in carrion crows and 16 other bird species with different diets in Beijing,China.Our findings revealed that the dominant gut microbiota in carrion crows was primarily composed of Proteobacteria(75.51%)and Firmicutes(22.37%).Significant differences were observed in the relative abundance of Enterococcus faecalis among groups,highlighting its potential as a biomarker of facultative scavenging behavior in carrion crows.Subsequently,E.faecalis isolated from carrion crows was transplanted into model mice to explore the protective effects of this bacterial community against Salmonella enterica infection.Results showed that E.faecalis down-regulated the expression of pro-inflammatory cytokines tumor necrosis factor alpha(TNF-α),interferon gamma(IFN-γ),and interleukin 6(IL-6),prevented S.enterica colonization,and regulated the composition of gut microbiota in mice,thereby modulating the host’s immune regulatory capacity.Therefore,E.faecalis exerts immunoregulatory and anti-pathogenic functions in carrion crows engaged in scavenging behavior,offering a representative case of how the gut microbiota contributes to the protection of hosts with specialized diets.
基金funded by the National Science Centre of Poland(grant no.2021/41/B/NZ8/00474).
文摘Aggregations of juveniles are dominant forms of social life in some insect groups.Larval societies are shaped by competitive and cooperative interactions of the larvae,in parallel with parental effects.Colonies of necrophagous larvae are excellent systems to study these relationships.Necrodes littoralis(Staphylinidae:Silphinae),a carrion beetle that colonizes cadavers of large vertebrates,forms massive juvenile aggregations.By spreading over carrion anal and oral exudates,the beetles form the feeding matrix,in which the heat is produced and by which adults presumably affect the fitness of the larvae.We predict that exploitative competition shapes the behavior of N.littoralis larvae in their aggregations.However,cooperative interactions may also operate in these systems due mainly to the benefits of collective exodigestion.Moreover,indirect parental effects(i.e.,formation of the feeding matrix)probably modulate larval interactions within the aggregations.By manipulating parental effects(present/absent)and larval density(0.02−1.9 larvae/g of meat),we found a strong negative group-size effect on fitness components of N.littoralis,in colonies with parental effects over almost the entire density range,and in colonies without parental effects for densities larger than 0.5 larva/g.This was accompanied by positive group-size effects in terms of development time(it shortened with larval density)and thermogenesis(it increased with larval density).A pronounced positive group-size effect on juvenile fitness was found only in colonies without parental effects and only in the low-density range.These results support the hypothesis that larval societies of N.littoralis are shaped by exploitation competition.
基金MJP has a postdoctoral fellowship from CONCYTEC/FONDECYT[grant number:CG05-2013-FONDECYT]and Programa Nacional de Innovación para la Competitividad y Productividad(Innóvate Perú),under the contract 117-PNICP-PIAP-2015 PerúCG has a PhD fellowship of the ISCIII[FI12/00561]JR has a fellowship from the program I3,of the ISCIII[grant number:CES11/012].
文摘Carrion’s disease is a neglected tropical disease caused by Bartonella bacilliformis,a vector-borne pathogen restricted to the Andean valleys of Peru,Ecuador and Colombia.Carrion’s disease is a biphasic illness;in the acute phase the case-fatality rate can be as high as 88%,related to high parasitemia,arriving to almost all erythrocytes,and secondary bacterial infections close related with the development of transient immunosuppression in the earlier illness phases.In addition,there are an undefined number of asymptomatic carriers that are reservoirs of the etiological agent of Carrion’s disease in endemic areas,they make take into account due to they are the perpetuators of this disease.The actual scenario of Carrion’s disease,in which the illness is arriving to new areas,due to the expansion of the vector’s distribution,suggests that now may be a crucial time to design a strategy focusing on its elimination.
文摘Proton pump inhibitors strongly inhibit gastric acid production,but digestion problems do not generally arise.We can intake almost ordinary food even after total gastrectomy.Small intestine itself can digest and absorb food using various digestive enzymes without digestion in the stomach.The pH level of gastric acid in humans is much lower than that of most animals,and very close to that of carrion-eating animals called scavengers.It is assumed that ancient humans became bipedal approximately 4 million years ago.It was difficult for humans,who just started unstable bipedal locomotion,to catch quadrupedal-walking animals that can move faster,without special hunting tools.They may have eaten remaining carcasses,which is mainly the leftovers of carnivora species,as animalderived food.The benefit to produce a volume of gastric acid for humans is carrion eating,in which disinfection by gastric acid is important.Humans produce a high concentration of gastric acid to enable consumption of a diet containing some bacteria and support this lifestyle by consuming significant energy to protect themselves from gastric acid.Now,the opportunity for strong deleterious bacteria to enter the gastrointestinal tract has decreased because of the organized clean environment.If this hygienic environment is maintained for a long time,our gastric acid level must be decreased gradually.
文摘When female blow flies Lucilia sericata and Phormia regina （Diptera： Cal- liphoridae） oviposit in aggregations on carrion, even-aged larval offspring reportedly de- velop faster, and fewer are parasitized or preyed upon. The benefits of aggregated ovipo- sition equally affect con- and heterospecific larvae sharing a resource. The benefits imply that female blow flies engage in coordinated, pheromone-mediated oviposition behavior. Yet, repeated attempts to identify oviposition pheromones have failed invoking doubt that they exist. Simply by regurgitating and feeding on carrion, flies may produce attractive semiochemicals. If flies were to aggregate in response to feeding flies rather than oviposit- ing flies, then the semiochemical cue（s） may be associated with the salivary gland. Working with L. sericata and P.. regina and using liver as a surrogate oviposition medium, we test the hypotheses, and present data in their support, that （i） gravid or nongravid females ovipositing and/or feeding on liver enhance its attractiveness to gravid and nongravid fe- males; （ii） females respond to semiochemicals from feeding heterospecific females; （iii） females respond equally well to semiochemicals from feeding con- and heterospecific females; （iv） macerated head tissues of females applied to liver enhance its attractiveness; and （v） females in direct contact with and feeding on liver, but not when next to yet physically separated from liver, enhance attraction of flies. We conclude that oviposition site-seeking females do not respond to an oviposition pheromone. Instead, they appear to coopt semiochemicals associated with feeding flies as resource indicators, taking chances that resources are suitable for oviposition, and that ovipositing flies are present.
文摘Decomposition research is still in its infancy,but significant advances have occurred within forensic anthropology and other disciplines in the past several decades.Decomposition research in forensic anthropology has primarily focused on estimating the postmortem interval(PMI),detecting clandestine remains,and interpreting the context of the scene.Additionally,while much of the work has focused on forensic-related questions,an interdisciplinary focus on the ecology of decomposition has also advanced our knowledge.The purpose of this article is to highlight some of the fundamental shifts that have occurred to advance decomposition research,such as the role of primary extrinsic factors,the application of decomposition research to the detection of clandestine remains and the estimation of the PMI in forensic anthropology casework.Future research in decomposition should focus on the collection of standardized data,the incorporation of ecological and evolutionary theory,more rigorous statistical analyses,examination of extended PMIs,greater emphasis on aquatic decomposition and interdisciplinary or transdisciplinary research,and the use of human cadavers to get forensically reliable data.
文摘Necrophagous blowflies(Diptera:Calliphoridae)such as Calliphora vicina,a cold-tolerant species,and L ucilia serie ata,a warm-adapted species,are pioneer carrion・breeder.Although these two species have different temperature preferences,larvae aggregate actively and often feed simultaneously on carrion.The hypothesis to be tested was that L.sericata benefits from the association with C.vicina at lower temperatures(i.e.,15℃)and that C.vicina derives greater benefits from this association at higher temperatures(i.e.,28℃).Therefore,both species were raised at these two constant temperatures from first instars to adults under three different conditions:monospecific low-density,monospecific high-density,and heterospecific high-density.The time until larval migration,surface area of puparia,and survival rates were determined for each condition.Differences between these fitness-related traits were found between species,temperatures,group densities,and species compositions.At 28°C,C.vicina larvae bred in heterospecific groups migrated significantly earlier and in higher numbers than that under same density conspecific con・ditions,with a lower mortality rate.At 15°C,both species benefited from high-density heterospecific associations,expressed by faster development and larger puparia.In conclusion,necrophagous larvae benefited from heterospecific aggregations at suboptima 1 temperatures by adapting their migration time to that of the faster species.Since temperature changes throughout the day and over the year,the beneficiary of such a collective association also changes.The costs involved and deviations to the temperature-size rule highlight the complexity of the carrion ecosystem.
