Necrophage

Necrophages are organisms that obtain nutrients by consuming decomposing dead animal biomass, such as the muscle and soft tissue of carcasses and corpses (also known as carrion).[1][2][3] The term derives from Greek nekros, meaning 'dead', and phagein, meaning 'to eat'.[1] Many hundreds of necrophagous species have been identified including invertebrates in the insect,[2] malacostracan[4] and gastropod[5] classes and vertebrates such as vultures, hyenas, quolls and wolves.[4]
Necrophagous insects are important in forensic science[2] as the presence of some species (e.g. Calliphora vomitoria) in a body, coupled with information on their development stage (e.g. egg, larva, pupa), can yield information on time of death.[6][7] Information on the insect species present can also be used as evidence that a body has been moved,[6][8] and analysis of insect tissue can be used as evidence that drugs or other substances were in the body.[6][9]
Necrophages are useful for other purposes too. In healthcare, green bottle fly larvae are sometimes used to remove necrotic (dead) tissue from non-healing wounds,[10][11] and in waste management, black soldier fly larvae are used to convert decomposing organic waste into animal feed.[12][13] Biotechnological applications for necrophage-derived genes, molecules and microbes are also being explored.[4][14]
Classification
[edit]Necrophages can be classified according to their nutritional reliance on carrion and also their level of adaptation to carrion feeding. Animals are described as 'obligate necrophages' if they use carrion as their sole or main food source and depend on carrion for survival or reproduction.[4] The term 'specialists' is also sometimes used in recognition that these animals have traits favoring necrophagy and making other feeding behaviors difficult.[15] For example, large wingspans facilitate the energy-efficient gliding vultures need to cover long distances in search of carrion,[16] but reduce the agility needed to kill prey.[17] Animals that eat carrion opportunistically and retain the traits needed to find and consume other food sources are described as 'facultative necrophages' and 'generalists'.[4][17] Both obligate and facultative necrophages are sometimes sub-classified as 'wet' and 'dry' feeders.[18] These terms differentiate animals feeding on moist, putrefying tissue from animals feeding on desiccated and keratinized tissues.[18]
Invertebrates
[edit]Flies
[edit]
The European bone skipper, Thyreophora cynophila, is an obligately necrophagous fly. It relies on carrion bone marrow in the first stage of its life cycle.[19] Many other types of fly are facultatively necrophagous. Examples commonly found on land include blow flies, flesh flies, muscid flies, ensign flies and thread-horns. Other necrophagous flies, for example black flies and lake flies, are semi-aquatic.[2][20] Types of carrion fed upon include wildlife,[21][22][23] livestock and poultry carcasses, slaughterhouse and fishing discards, and human bodies.[4] Necrophagous flies detect these dead bodies and body parts via minute traces of decomposition odor in the air.[24][25]
The diversity and abundance of necrophagous fly species vary geographically and seasonally.[6][19][25] For example, Chrysomya species are present in subtropical regions of the USA but are rare in most of Canada.[6] This geographic variation is attributable to factors such as soil type and meteorological conditions, and the effects these have on carrion decomposition.[6] Whether urbanization affects fly species richness is open to dispute.[25][26] Seasonally, many necrophagous fly species are observed in higher abundance in summer,[25] but Thyreophora cynophila is more active in winter.[19]
Flies play a critical role in forensic science as they are often the first insects to discover and colonize human remains.[6][20] Blow flies can arrive within minutes and begin laying eggs in the nose, mouth and other openings. Because adult flies very rarely deposit eggs in live hosts, the age of the developing fly larvae can be used to estimate time of death.[6] Fly larvae can also provide information regarding cause of death because necrophagous flies deposit their eggs in any open wounds.[6]
Bees
[edit]Vulture bees are a small group of obligately necrophagous bees in the Trigona genus.[3][27] Trigona worker bees play a similar role to worker bees in the Apis genus; however, along with collecting pollen, nectar, and plant resins, Trigona workers also collect carrion.[3][28] Although pollen is associated with higher energy value, carrion is preferred by Trigona bees because it is biochemically easier to extract energy from.[27] This dead animal tissue is used as a source of amino acids too.[29]
Cerumen pots are utilized by some Trigona species, such as T. necrophaga, as vesicles to store foodstuff.[30] The foodstuff of T. necrophaga consists of both honey and carrion from vertebrate carcasses.[3] Ultimately, the stored food is utilized by developing larvae and the worker bee itself as a source of nutrition and energy. Due to the rapid decomposition of carrion, especially in warm temperatures, the bees must efficiently metabolize the carrion to avoid rotten carrion in their cerumen pots.[3]
Trigona hypogea communicate the presence of a valuable carcass through olfactory signals.[3] The bees create an odour trail between their nest and the prospective animal carcass; thus, the bees recruit the other nest members to respond and exploit the corpse's resources rapidly. Additionally, interspecific competition is observed in Trigona hypogea bees. The bees are observed to defend their colonized food item, including but not limited to a monkey, lizard, fish, or snake carcass, from competing necrophages, such as flies.
Beetles
[edit]
Numerous beetles in the Nicrophorus genus are obligately necrophagous, for example Nicrophorus americanus and N. vespilloides.[4] Many other beetles are facultative necrophages including checkered beetles,[21] dermestid beetles,[6] diving beetles,[20][31] scarab beetles,[32] silphine beetles[6] and water scavenger beetles.[31] Types of carrion fed upon include wildlife, livestock and poultry carcasses, livestock viscera and human bodies.[4] Necrophagous beetles locate this carrion using antennal chemoreceptors[33][34] sensitive to sulfur-containing compounds.[35]
N. vespilloides and other burying beetles preferentially feed on small carcasses (e.g. rodents and small birds)[35] as these are easier to transport, clean and conceal from competitors.[34][36] Diving beetles, scarab beetles and water scavenger beetles have all been observed feeding on amphibian carrion (e.g. granular toads and tree frogs).[31][32] The scarab beetle Scybalocanthon nigriceps uses its front legs and clypeus to shape frog carrion into pellets for eventual consumption.[32] Other scarab beetles, for example, Coprophanaeus ensifer, build their burrows near carcasses for easier transportation of carrion pieces to offspring.[37]
Beetles that feed on human remains are important in forensic science. Terrestrial beetles such as checkered beetles and dermestid beetles colonize bodies in a predictable sequence and have well-characterized life cycles, so they can sometimes be used to estimate time of death.[6][38] Aquatic beetles are less useful for estimating time of death[6] but can cause physical damage to submerged bodies that must be distinguished from inflicted injuries when determining cause of death.[20] For example, the facultatively necrophagous diving beetle Meridiorhantus validus creates postmortem channels and chambers in human bodies that must be differentiated from antemortem piercing injuries.[20]
Marine snails
[edit]Nassa mud snails such as Nassarius festivus and Nassarius clarus scavenge on dead and decaying animal matter in the intertidal zone of eulittoral soft shores.[5][39] At Shark Bay in Australia, Nassarius clarus feeds on the carrion of fishes and bivalves.[39] In the presence of carrion, the animal's proboscis performs a search reaction followed by a quick onset of feeding. When faced with a competitor, such as a hermit crab, at the site of the carrion, the Nassarius clarus attack the competition to defend their meal. Nassarius clarus are attracted to fish and bivalve carrion to a distance of 26 miles and have a heightened interest in areas where the sand has been disturbed; thus, indicating the potential presence of organic detritus or damaged fauna.
Vertebrates
[edit]
Vultures
[edit]Many vulture species are obligately necrophagous including the bearded vulture, black vulture, cinereous vulture, Eurasian griffon, Himalayan vulture, king vulture and turkey vulture.[4] Types of carrion fed upon include dead wildlife, livestock, poultry and companion animals, human remains (sky burial), hunting discards, slaughterhouse offal and roadkill.[4] Typically, muscle tissue is consumed,[40] but bearded vultures feed on bones and bone marrow.[41] In addition to eating carrion, Egyptian vultures feed on small live animals such as turtles, eggs and rotting fruit.[42][43][44]
Some human activities have had an adverse impact on vultures in Sicily,[42] the Azerbaijan Republic[45] and other countries.[46] For example, changes in farming practices such as the indoor raising of cattle and incineration or burial of cattle carcasses have reduced food availability for Eurasian griffon vultures.[42][45] Shootings of birds, removal of nestlings from nests,[45] and drug pollution[46] have also contributed to declines in vulture populations.
Role in forensic entomology
[edit]Necrophagous flies and beetles play an important role in forensic entomology due to their postmortem colonization of human remains.[6][20] For example, in homicide cases, forensic medical examiners can sometimes determine the minimum post-mortem interval based on the fly and beetle species present in the body and their development stage.[6][47] This is because these insects rarely deposit eggs in live hosts, they colonize bodies in a predictable sequence following death, and information is available on how long it takes different species to reach different stages of development.[6] Because insect arrival and departure time and larval development time are affected by seasonal changes,[48] temperature,[49] moisture levels,[50] air exposure,[51] geographical region,[52] and other factors, these must all be carefully considered when estimating minimum post-mortem interval.[53]
See also
[edit]References
[edit]- ^ a b Getz, WM (2011). "Biomass transformation webs provide a unified approach to consumer-resource modelling". Ecology Letters. 14 (2): 113–124. Bibcode:2011EcolL..14..113G. doi:10.1111/j.1461-0248.2010.01566.x. PMC 3032891. PMID 21199247.
- ^ a b c d Keh, B (1985). "Scope and applications of forensic entomology". Annual Review of Entomology. 30 (1): 137–154. doi:10.1146/annurev.en.30.010185.001033. PMID 3882048.
- ^ a b c d e f Gilliam, M; Buchmann, SL; Lorenz, BJ; Roubik, DW (1985). "Microbiology of the larval provisions of the stingless bee, Trigona hypogea, an obligate necrophage". Biotropica. 17 (1): 28. Bibcode:1985Biotr..17...28G. doi:10.2307/2388374. JSTOR 2388374.
- ^ a b c d e f g h i j Cushnie, TP; Luang-In, V; Sexton, DW (2025). "Necrophages and necrophiles: a review of their antibacterial defenses and biotechnological potential". Critical Reviews in Biotechnology. 45 (3): 625–642. doi:10.1080/07388551.2024.2389175. PMID 39198023.
- ^ a b Cheung, SG; Lam, S (1999). "Effect of food availability on egg production and packaging in the intertidal scavenging gastropod Nassarius festivus". Marine Biology. 135 (2): 281–287. Bibcode:1999MarBi.135..281C. doi:10.1007/s002270050625. S2CID 85201716.
- ^ a b c d e f g h i j k l m n o p Allen JC, Anderson GS, Benecke M, et al. (2001). Byrd JH, Castner JL (eds.). Forensic Entomology: The Utility of Arthropods in Legal Investigations. London: CRC Press. pp. 43–80, 143–176, 263–286, 331–340. ISBN 978-0849381201.
- ^ Harvey, ML; Gasz, NE; Voss, SC (2016). "Entomology-based methods for estimation of postmortem interval". Research and Reports in Forensic Medical Science. 6: 1–9. doi:10.2147/RRFMS.S68867. hdl:10536/DRO/DU:30084865.
- ^ Charabidze, D; Gosselin, M; Hedouin, V. (2017). "Use of necrophagous insects as evidence of cadaver relocation: myth or reality?". PeerJ. 5: e3506. doi:10.7717/peerj.3506. PMC 5543926. PMID 28785513.
- ^ Chophi, R; Sharma, S; Sharma, S; Singh, R (2019). "Forensic entomotoxicology: current concepts, trends and challenges". Journal of Forensic and Legal Medicine. 67: 28–36. doi:10.1016/j.jflm.2019.07.010. PMID 31398663.
- ^ Gethin, G; Cowman, S; Kolbach, DN (2015). "Debridement for venous leg ulcers". Cochrane Database of Systematic Reviews. 2015 (9): CD008599. doi:10.1002/14651858.CD008599.pub2. PMC 6486053. PMID 26368002.
- ^ Shamloul, G; Khachemoune, A (2023). "Reappraisal and updated review of maggot debridement therapy in chronic lower extremity ulcers". International Journal of Dermatology. 62 (7): 962–968. doi:10.1111/ijd.16619. PMID 36880424.
- ^ Tomberlin, JK; van Huis, A (2020). "Black soldier fly from pest to 'crown jewel' of the insects as feed industry: an historical perspective". Journal of Insects as Food and Feed. 6 (1): 1–4. doi:10.3920/JIFF2020.0003. ISSN 2352-4588. S2CID 214068576.
- ^ Barragán-Fonseca, KB; Gómez, D; Lalander, CH; Dzepe, D; Chia, SY (2025). "Review - Insect farming for food and feed in the Global South: focus on black soldier fly production". Animal. doi:10.1016/j.animal.2024.101397. PMID 39800645.
- ^ Cushnie T, Sexton D, Luang-In V (2024). "Antibacterial discovery: how scavengers avoid infection and what we can learn from them". The Conversation. Retrieved March 16, 2025.
- ^ Carrasco-Garcia, R; Barroso, P; Perez-Olivares, J; Montoro, V; Vicente, J (2018). "Consumption of big game remains by scavengers: a potential risk as regards disease transmission in central Spain". Frontiers in Veterinary Science. 5: 4. doi:10.3389/fvets.2018.00004. PMC 5840163. PMID 29552564.
- ^ DeVault, TL; Rhodes, OE; Shivik, JA (2003). "Scavenging by vertebrates: behavioral, ecological, and evolutionary perspectives on an important energy transfer pathway in terrestrial ecosystems". Oikos. 102 (2): 225–234. Bibcode:2003Oikos.102..225D. doi:10.1034/j.1600-0706.2003.12378.x.
- ^ a b Whelan, CJ; Wenny, DG; Marquis, RJ (2008). "Ecosystem services provided by birds". Annals of the New York Academy of Sciences. 1134 (1): 25–60. Bibcode:2008NYASA1134...25W. doi:10.1196/annals.1439.003. PMID 18566089.
- ^ a b Villet, MH (2011). "African carrion ecosystems and their insect communities in relation to forensic entomology" (PDF). Pest Technology. 5 (1): 1–15.
- ^ a b c Gu, X; Haelewaters, D; Krawczynski, R; Vanpoucke, S; Wagner, H; Wiegleb, G (2014). "Carcass ecology – more than just beetles". Entomologische Berichten. 74 (1–2): 68–74. ISSN 0013-8827.
- ^ a b c d e f Oses-Rivera, CA; Tosti-Croce Astesiano, EC (2020). "First report of Rhantus validus Sharp (Coleoptera: Dytiscidae) as necrophage and generator of postmortem artifacts in a human corpse found in an artificial freshwater pond from the Región de La Araucanía, Chile". Revista Chilena de Entomología. 46 (1): 81–86. doi:10.35249/rche.46.1.20.11. S2CID 212861052.
- ^ a b Okiwelu, SN; Ikpamii, T; Umeozor, OC (2010). "Arthropods associated with mammalian carcasses in Rivers State, Nigeria". African Journal of Biomedical Research. 11 (3). doi:10.4314/ajbr.v11i3.50754. hdl:1807/54150.
- ^ Al-Mesbah, H; Moffatt, C; El-Azazy, OME; Majeed, QAH (2012). "The decomposition of rabbit carcasses and associated necrophagous Diptera in Kuwait". Forensic Science International. 217 (1–3): 27–31. doi:10.1016/j.forsciint.2011.09.021. PMID 22018747.
- ^ Amat, E (2010). "Notes on necrophagous flies (Diptera: Calyptratae) associated to fish carrion in Colombian Amazon". Acta Amazonica. 40 (2): 397–400. doi:10.1590/s0044-59672010000200018.
- ^ Mondor, EB; Tremblay, MN; Tomberlin, JK; Benbow, EM; Tarone, AM; Crippen, TL (2012). "The ecology of carrion decomposition". Nature Education Knowledge. 3 (10): 21.
- ^ a b c d Carmo, RFR; Vasconcelos, SD (2016). "Assemblage of necrophagous Diptera in Atlantic insular environments and response to different levels of human presence". Neotropical Entomology. 45 (5): 471–481. Bibcode:2016NeEnt..45..471C. doi:10.1007/s13744-016-0394-x. PMID 27040531. S2CID 8820120.
- ^ Hwang, C.; Turner, BD (2005). "Spatial and temporal variability of necrophagous Diptera from urban to rural areas". Medical and Veterinary Entomology. 19 (4): 379–391. doi:10.1111/j.1365-2915.2005.00583.x. PMID 16336303. S2CID 10442916.
- ^ a b Mateus, S; Noll, FB (2004). "Predatory behavior in a necrophagous bee Trigona hypogea (Hymenoptera; Apidae, Meliponini)". Naturwissenschaften. 91 (2): 94–96. Bibcode:2004NW.....91...94M. doi:10.1007/s00114-003-0497-1. PMID 14991148. S2CID 26518321.
- ^ Camargo, JMF; Roubik, DW (1991). "Systematics and bionomics of the apoid obligate necrophages: the Trigona hypogea group (Hymenoptera: Apidae; Meliponinae)". Biological Journal of the Linnean Society. 44 (1): 13–39. doi:10.1111/j.1095-8312.1991.tb00604.x.
- ^ Roubik, DW (2023). "Stingless bee (Apidae: Apinae: Meliponini) ecology". Annual Review of Entomology. 68: 231–256. doi:10.1146/annurev-ento-120120-103938. PMID 3619840.
- ^ Serrão, JE; da Cruz-Landim, C; Silva-de-Moraes, RLM (1997). "Morphological and biochemical analysis of the stored and larval food of an obligate necrophagous bee, Trigona hypogea". Insectes Sociaux. 44 (4): 337–345. doi:10.1007/s000400050055. S2CID 33884946.
- ^ a b c Silva-Soares, T (2019). "Necrophagy on Rhinella granulosa (Amphibia, Anura, Bufonidae) by the aquatic beetle families Hydrophilidae and Dytiscidae (Insecta, Coleoptera) in Caatinga environment, Northeastern Brazil". Herpetology Notes. 12: 869–872.
- ^ a b c Messas, YF; Souza, HS; Schiffler, G; Sobczak, JF (2012). "First record of necrophagy by Scybalocanthon nigriceps Harold (Coleoptera, Scarabaeidae, Scarabaeinae)". Revista Brasileira de Entomologia. 56 (2): 257–258. doi:10.1590/s0085-56262012005000026.
- ^ Dekeirsschieter, J; Verheggen, F; Lognay, G; Haubruge, E. (2011). "Large carrion beetles (Coleoptera, Silphidae) in western Europe: a review". Biotechnology, Agronomy, Society and Environment. 15 (3): 435–447.
- ^ a b Scott, MP (1998). "The ecology and behavior of burying beetles". Annual Review of Entomology. 43 (1): 595–618. doi:10.1146/annurev.ento.43.1.595.
- ^ a b Kalinová, B; Podskalská, H; Růzicka, J; Hoskovec, M (2009). "Irresistible bouquet of death-how are burying beetles (Coleoptera: Silphidae: Nicrophorus) attracted by carcasses". Naturwissenschaften. 96 (8): 889–99. doi:10.1007/s00114-009-0545-6. PMID 19404598.
- ^ Duarte, A; Welch, M; Swannack, C; Wagner, J; Kilner, RM (2018). "Strategies for managing rival bacterial communities: Lessons from burying beetles". Journal of Animal Ecology. 87 (2): 414–427. doi:10.1111/1365-2656.12725. PMC 5836980. PMID 28682460.
- ^ Otronen, M (1988). "Intra-and intersexual interactions at breeding burrows in the horned beetle, Coprophanaeus ensifer". Animal Behaviour. 36 (3): 741–748. doi:10.1016/S0003-3472(88)80157-X.
- ^ Kulshrestha, P; Satpathy, DK (2001). "Use of beetles in forensic entomology". Forensic Science International. 120 (1–2): 15–17. doi:10.1016/S0379-0738(01)00410-8. PMID 11457603.
- ^ a b Morton, B (2001). "The biology of Hipponix australis (Gastropoda: Hipponicidae) on Nassarius pauperatus (Nassariidae) in Princess Royal Harbour, Western Australia". Journal of Molluscan Studies. 67 (3): 247–255. doi:10.1093/mollus/67.3.247.
- ^ Demo, C; Cansi, ER; Kosmann, C; Pujol-Luz, JR (2013). "Vultures and others scavenger vertebrates associated with man-sized pig carcasses: a perspective in forensic taphonomy". Zoologia (Curitiba). 30 (5): 574–576. doi:10.1590/s1984-46702013000500010.
- ^ "Bearded Vultures — Europe's rarest vulture". Vulture Conservation Foundation. Retrieved March 28, 2025.
- ^ a b c Di Vittorio, M; López-López, P; Cortone, G; Luiselli, L (2017). "The diet of the Egyptian vulture (Neophron percnopterus) in Sicily: temporal variation and conservation implications". Vie et Milieu. 67 (1): 7–14.
- ^ Prakash, V; Nanjappa, C (1988). "An instance of active predation by scavenger vulture (Neophron p. ginginianus) on checkered keelback watersnake (Xenochrophis piscator) in Keoladeo National Park, Bharatpur, Rajasthan". The Journal of the Bombay Natural History Society. 85 (2): 419.
- ^ "Egyptian vultures — Europe's only globally endangered vulture". Vulture Conservation Foundation. Retrieved March 28, 2025.
- ^ a b c Karimov, T (2015). "Main limiting factors affecting biological parameters of necrophage birds". The Journal of V.N.Karazin Kharkiv National University. Series «Biology». 24 (1153): 68–72.
- ^ a b Oaks, JL; Gilbert, M; Virani, MZ; Watson, RT; Meteyer, CU; Rideout, BA; Shivaprasad, HL; Ahmed, S; Chaudhry, MJI; Arshad, M; Mahmood, S; Ali, A & Khan, AA (2004). "Diclofenac residues as the cause of vulture population decline in Pakistan". Nature. 427 (6975): 630–633. Bibcode:2004Natur.427..630O. doi:10.1038/nature02317. PMID 14745453. S2CID 16146840.
- ^ Oliveira, TC; Vasconcelos, SD (2010). "Insects (Diptera) associated with cadavers at the Institute of Legal Medicine in Pernambuco, Brazil: Implications for forensic entomology". Forensic Science International. 198 (1–3): 97–102. doi:10.1016/j.forsciint.2010.01.011. PMID 20181449.
- ^ Archer, MS (2003). "Annual variation in arrival and departure times of carrion insects at carcasses: implications for succession studies in forensic entomology". Australian Journal of Zoology. 51 (6): 569. doi:10.1071/zo03053.
- ^ Charabidze, D; Hedouin, V (2019). "Temperature: the weak point of forensic entomology". International Journal of Legal Medicine. 133 (2): 633–639. doi:10.1007/s00414-018-1898-1. PMID 30043225. S2CID 51714494.
- ^ Campobasso CP, Di Vella G, Introna F (2001). "Factors affecting decomposition and Diptera colonization". Forensic Science International. 120 (1–2): 18–27. doi:10.1016/S0379-0738(01)00411-X. PMID 11457604.
- ^ Goff ML (2000). A Fly for the Prosecution. Cambridge, Massachusetts: Harvard University Press.
- ^ Kulshrestha, P; Satpathy, DK (2001). "Use of beetles in forensic entomology". Forensic Science International. 120 (1–2): 15–17. doi:10.1016/S0379-0738(01)00410-8. PMID 11457603.
- ^ Amendt J, Campobasso CP, Gaudry E, Reiter C, LeBlanc HN, Hall MJ (2007). "Best practice in forensic entomology--standards and guidelines". International Journal of Legal Medicine. 121 (2): 90–104. doi:10.1007/s00414-006-0086-x. PMID 16633812.
External links
[edit]The dictionary definition of necrophage at Wiktionary