Editing Silphidae

{{update|date=January 2025|reason=Silphidae is now considered a subfamily of [[Staphylinidae]] in a number of recently published works, e.g. in [https://royalsocietypublishing.org/doi/10.1098/rsos.211771], [https://doi.org/10.3897/zookeys.1200.122835] and [https://doi.org/10.3897/zookeys.1194.106440], as well as in [https://bugguide.net/node/view/167 BugGuide]. Subfamilies Nicrophorinae and Silphinae are now tribes Nicrophorini and Silphini}}
{{Short description|Family of beetles}}
{{Automatic taxobox
| name = Silphidae
| display_parents = 3
| fossil_range = {{fossilrange|Middle Jurassic|Present}}
| image = Nicrophorus.vespillo.jpg
| image_caption = ''[[Nicrophorus vespillo]]''
| taxon = Silphidae
| authority = [[Pierre André Latreille|Latreille]], 1806<ref>{{cite journal|first1=Patrice|last1=Bouchard|first2=Yves|last2=Bousquet|first3=Anthony E.|last3=Davies|first4=Miguel A.|last4=Alonso-Zarazaga|first5=John F.|last5=Lawrence|first6=Chris H. C.|last6=Lyal|first7=Alfred F.|last7=Newton|first8=Chris A. M.|last8=Reid|first9=Michael|last9=Schmitt|first10=S. Adam|last10=Ślipiński|first11=Andrew B. T.|last11=Smith|year=2011|title=Family-group names in Coleoptera (Insecta)|journal=[[ZooKeys]]|issue=88|pages=1–972|doi=10.3897/zookeys.88.807|doi-access=free|pmc=3088472|pmid=21594053|bibcode=2011ZooK...88....1B }}</ref>
| subdivision_ranks = Subfamilies
| subdivision = [[Nicrophorinae]] <small>[[William Kirby (entomologist)|Kirby]], 1837</small><br/>
[[Silphinae]] <small>[[Pierre André Latreille|Latreille]], 1806</small>
}}

'''Silphidae''' is a family of [[beetle]]s that are known commonly as '''large carrion beetles''', '''carrion beetles''' or '''burying beetles'''. There are two [[family (biology)|subfamilies]]: [[Silphinae]] and [[Nicrophorinae]]. Members of Nicrophorinae are sometimes known as '''burying beetles''' or '''sexton beetles'''. The number of species is relatively small, at around two hundred. They are more diverse in the temperate region although a few tropical endemics are known. Both subfamilies feed on decaying [[organic matter]] such as dead animals. The subfamilies differ in which uses [[parenting|parental care]] and which types of carcasses they prefer. Silphidae are considered to be of importance to [[forensic entomologist]]s because when they are found on a decaying body they are used to help estimate a [[post-mortem interval]].

==Taxonomy, evolution, and etymology==
The family Silphidae belongs to the order [[beetle|Coleoptera]]. They are commonly referred to as carrion beetles or burying beetles and are usually associated with [[carrion]], [[fungus|fungi]], and [[Feces|dung]]. In the past, members of the family [[Agyrtidae]] were included. This family has two subfamilies, [[Silphinae]] and [[Nicrophorini|Nicrophorinae]]. The antenna is made up of 15 segments and is capitate (ending in an abruptly capped club) in the Nicrophorinae and has a more gradual club shape in the Silphinae. The subfamilies also differ in behavior. Members of the subfamily Silphinae show little to no care for their young and breed on large [[carrion]]. Nicrophorinae breed on small animal [[carrion]] and will bury themselves and their food to rear their offspring in a bi-parental manner.<ref>{{cite book|author=Eggert, A.|author2=Muller, J. K. |title=Bi-parental care and social evolution in burying beetles: Lessons from the larder in Social Behavior in Insects and Arachnids|publisher= Cambridge University Press|place=Cambridge | year= 1997|pages=1–541}}</ref> There are approximately 183 species in this family, which are found worldwide although they are more common in temperate regions. ''[[Nicrophorus americanus]]'', known as the American burying beetle, is an [[endangered species]].<ref>{{cite journal|author=Backlund, Douglas C.|author2=Gary M. Marrone|author3=Christopher K. Williams|author4=Kelley Tilmon|name-list-style=amp |title= Population Estimate of the Endangered American Burying Beetle, Nicrophorus americanus Olivier (Coleoptera: Silphidae) in South Dakota.|journal=The Coleopterists Bulletin| year=2008 |volume= 62|issue =4|pages=9–15 |doi=10.1649/982.1 |s2cid=85841685}}</ref>

The oldest fossils of silphids are known from the Middle Jurassic (~ 163 million years ago) [[Daohugou Bed]] in Northern China.<ref>{{Cite journal|last1=Cai|first1=Chen-Yang|last2=Thayer|first2=Margaret K.|last3=Engel|first3=Michael S.|last4=Newton|first4=Alfred F.|last5=Ortega-Blanco|first5=Jaime|last6=Wang|first6=Bo|last7=Wang|first7=Xiang-Dong|last8=Huang|first8=Di-Ying|date=2014-09-30|title=Early origin of parental care in Mesozoic carrion beetles|journal=Proceedings of the National Academy of Sciences|language=en|volume=111|issue=39|pages=14170–14174|doi=10.1073/pnas.1412280111|issn=0027-8424|pmid=25225362|pmc=4191754|bibcode=2014PNAS..11114170C|doi-access=free}}</ref><ref>{{Cite journal|last1=Toussaint|first1=Emmanuel F. A.|last2=Condamine|first2=Fabien L.|date=April 2016|title=To what extent do new fossil discoveries change our understanding of clade evolution? A cautionary tale from burying beetles (Coleoptera: Nicrophorus )|journal=Biological Journal of the Linnean Society|language=en|volume=117|issue=4|pages=686–704|doi=10.1111/bij.12710|doi-access=free}}</ref> Many Silphidae are flightless although they have wings. This loss is thought to be a result due to the changes in habitat over time. Researchers have found that most flight-capable species in this group feed on [[vertebrate]] carcasses, whereas flightless species will feed on soil [[invertebrate]]s. They also found that egg production increased with flight loss because of a more limited food supply.<ref>{{cite journal|author=Abe, T.|author2=Ikeda, H.|author3=Kagaya, T.|author4=Kubota, K.|year=2008|title=Evolutionary Relationships Among Food Habitat, Loss of Flight, and Reproductive Traits: Life-History Evolution in the Silphinae(Coleoptera:Silphidae)|pages=2065–2079| journal=Evolution| volume=62|issue=8|doi=10.1111/j.1558-5646.2008.00432.x|pmid=18507741|doi-access=free}}</ref>
[[File:Ridged Carrion Beetle (Oiceoptoma inaequale).jpg|alt=Ridged Carrion Beetle (Oiceoptoma inaequale)|thumb|Ridged Carrion Beetle (''Oiceoptoma inaequale'')]]
The word "silphid" or "sylph", first seen in the sixteenth century in [[Paracelsus]]' works, refers to any race of spirits inhabiting the air and is described as mortal, but lacking soul. The word is also related to the Latin word ''silva'' meaning "forests" or "of the woods".<ref>Online Etymology Dictionary. https://www.etymonline.com/word/sylvan</ref>

==Diversity and distribution==
Silphidae are [[omnipresence|ubiquitous]] and are most abundant in the temperate zone. The diversity is also greater in the temperate zone and they are quite rare in the tropics although there are species endemic to the region. It is thought that ants, flies and other carrion feeders outcompete them in these regions.<ref>{{cite book|author=Ratcliffe B.C.|year=1996| title=The carrion beetles (Coleoptera: Silphidae) of Nebraska. Bulletin 13.|place=Lincoln, USA|publisher=University of Nebraska State Museum}}</ref> They vary in size from 7 to 45&nbsp;mm.<ref name=europe>{{cite journal | journal= Biotechnology, Agronomy, Society and Environment |year= 2011 |volume=15| issue=3| pages=435–447| title=Large carrion beetles (Coleoptera, Silphidae) in Western Europe: a review|author1=Dekeirsschieter, Jessica |author2=François Verheggen |author3=Georges Lognay |author4=Eric Haubruge |url=http://www.pressesagro.be/base/text/v15n3/435.pdf}}</ref>

There are about 46 different species of Silphidae in North America which include ''Heterosilpha ramosa'', ''Necrodes surinamensis'', ''[[Necrophila americana]]'', ''[[Nicrophorus americanus]]'', ''[[Nicrophorus carolinus]]'', ''[[Nicrophorus investigator]]'', ''[[Nicrophorus marginatus]]'', ''[[Nicrophorus orbicollis]]'', ''[[Nicrophorus tomentosus]]'', ''Oiceoptoma inaequale'', ''[[Oiceoptoma noveboracense]]'', ''Oiceoptoma rugulosum'', ''Thanatophilus lapponicus''.<ref name="book">{{cite book|author=Byrd, Jason H.|author2=Castner, James L. |title=Forensic Entomology: The Utility of Arthropods in Legal Investigations|place=Boca Raton|publisher=CRC Press LLC|year=2001|pages=10, 37, 189–199}}</ref><ref name=canada>{{cite book |title=The insects and arachnids of Canada. Part 13. The Carrion Beetles of Canada and Alaska. Coleoptera: Silphidae and Agyrtidae |author1=Anderson, RS |author2=SB Peck |name-list-style=amp |year=1985 |publisher=Agriculture Canada |url=http://www.esc-sec.ca/aafcmonographs/insects_and_arachnids_part_13.pdf |url-status=dead |archive-url=https://web.archive.org/web/20130615015936/http://esc-sec.ca/aafcmonographs/insects_and_arachnids_part_13.pdf |archive-date=2013-06-15 }}</ref> A species found in Great Britain is ''Oiceoptoma thoracicum''.

One species of ''Nicrophorus'', ''[[Nicrophorus nepalensis]]'', can be found primarily in the mountains of eastern Asia as well as along the Malay Archipelago. ''Nicrophorus nepalensis'' are found in the Indian subcontinent as well in the countries of India and Pakistan.

==Development==
Silphidae undergo [[holometabolism|holometabolous]] development. The development in the subfamily Silphinae proceeds at a slower rate than in Nicrophorinae. The Silphinae [[Biological life cycle|life cycle]] takes approximately 26 to 58 days to go from an egg to adult.{{Citation needed|date=May 2025}} The breakdown of this process is essential to [[forensic entomologist]]s. Eggs take two to seven days to hatch. The [[larva]]e will develop through three [[instar]]s on the [[carrion]] lasting for 10 to 30 days. After that time period is up the third instar larvae will venture away from the [[detritus]] to [[pupa]]te. Pupation takes 14 to 21 days; during this stage the wings become fully developed and sexual maturity is reached, sometimes called the [[imago]] or adult stage where the cycle is then repeated. The life cycle of the Nicrophorinae is generally quicker. [[Oviposition]] is done near the [[Carrion|carcass]] and eggs take 12 to 48 hours to hatch into [[larva]]e. The amount of food and [[parenting|parental care]] exhibited help determine the length of the larval stage. Pupation in this subfamily lasts six to eight days and is completed in the soil. The adult Nicrophorine will emerge from the soil and venture to find food and a mate.<ref name="book"/>

==Reproduction==
[[File:Necrophila americana (Linnaeus) pair.jpg|thumb|left|Male (left) and female ''[[Necrophila americana]]'']]
Nicrophorinae are well known for the habit of locating a [[Carrion|carcass]] and burying it by unearthing the soil underneath it. The burying behavior has seemingly evolved to prevent competition from other insects such as fly [[maggot]]s. It has been observed that the cooperation of the two parent beetles leads to breeding success. More likely than not a breeding pair will work together, but in cases where there is large [[carrion]] males try to boost their reproduction by emitting [[pheromone]]s. In this way, he will father more offspring, but the reproductive success of the primary female steadily declines. Sometimes, where there is a large carcass the likelihood of intense competition from flies leads to [[cooperative breeding|communal breeding]]. There appears to be a truce between females who would normally compete for the males, and in these cases cooperative behavior extends to females caring for each other's offspring. At the height of breeding season pairs of beetles may compete for the [[carrion]]. The losing pair will be ejected from the [[carrion]] and if any eggs have been laid they are killed so the new female can lay her own.<ref name="essential entomology">McGavin, George C. ''Essential Entomology: An Order-by-Order Introduction''. Oxford: Oxford University Press, 2001. pp. 62–66.</ref>

==Behavior and ecology==

=== Food===
[[File:Nicrophorus vespilloides in dead rodent.jpg|thumb|upright|''[[Nicrophorus vespilloides]]'' colonizing a dead rodent.]]
Silphid adults feed in a saprophagous manner: they colonize the [[carrion]] during all four stages of [[decomposition]], which are fresh, bloated, decay, and dry. The main areas of decomposition for adults are during both the bloated and decaying stages. Silphid larvae mainly inhabit during the decaying and dry stages of the [[carrion]]. The primary food source for the subfamily Silphinae is the [[maggot]] mass present on the [[detritus]]. Nicrophorinae will colonize the body earlier in decomposition in order to avoid competition with maggots. If there is a sufficiently large maggot mass they will not colonize the [[Carrion|carcass]]. The parental care exhibited by this subfamily is that the adult beetles regurgitate food into the mouths of the young larvae until they are mature. Silphinae colonize later in the decaying process and the adults eat the maggot mass, sometimes leaving little maggot evidence left to estimate a [[post-mortem interval]]. In the case of the sexton or burying beetles, Nicrophorinae, the adults will bury small animal carcasses and lay their eggs on it. In some species, a slight depression is made on the [[detritus]] for maturing larvae that the adult beetles feed and protect. In both subfamilies the larvae are observed to eat the decaying organic material while the adults mainly consume the maggots. Flies are the major [[competition|competitor]] of silphids for [[detritus]]. If a carcass is infested with maggots, many of the Nicrophorinae will abandon the carcass while members of Silphinae will feed on the maggots.<ref name="book"/>

===Defense===

Beetles have many different weapons available to protect them against [[predator]] attacks. The members of Silphidae have many different modifications that allow them to thrive in different [[ecological niche]]s including colour warnings (from [[aposematism]] to [[Batesian mimicry]]), chemical defenses and [[parenting|parental care]]. Silphines are usually dark in color consisting of gold, black and brown. This dark coloring allows them to blend into their environment. Many nicrophorines have bright orange coloring on their [[elytra]], which may serve as a warning to other predators.<ref name="Rat">Ratcliffe, B. The Carrion Beetles (Coleoptera:Silphidae) of Nebraska. ''Bulletin of the Nebraska State Museum''. Volume 13.</ref> Some species secrete a chemical from a rectal gland that consists of [[aliphatic acid]]s and [[terpene alcohol]]s. The secretion has a strong, foul odor and may be [[topical]]ly irritating to [[cockroach]]es and [[flies]]. The species ''[[Necrodes surinamensis]]'' ejects this secretion as a spray and can rotate the end of its abdomen to spray in all directions.<ref>{{cite journal|last1=Roach|first1=B.|last2=Eisner|first2=T.|last3=Meinwald|first3=J|title=The Defense Mechanisms of arthropods. 83. alpha-and beta-Necrodol, novel terpens from a carrion beetle (Necrodes surinamensis, Silphidae, Coleoptera)|journal=Journal of Organic Chemistry|date=1990|volume=55|issue=13|pages=4047–4051|doi=10.1021/jo00300a020}}</ref>

===Locomotion and navigation===

Walking is the primary form of locomotion for Silphidae. They are able to travel great distances to find [[Carrion|carcasses]] to breed and feed on. Beetles also have two sets of wings, the [[elytra]] and the hind wings. The hind wings are membranous and are modified for flying or swimming. There are some Silphidae who are able to fly, but others have lost this ability throughout [[evolution]]. When an animal dies, [[hydrogen sulfide]] and some [[cyclic compound]]s are released. Silphidae use their sense of smell to locate carcasses from a long distance by [[chemoreceptor]]s on their antennae, which are adapted to detect these chemicals.<ref>Evans, A. Hogue, J. ''Introduction to California Beetles''. University of California Press 2004. p. 154–156.</ref> At a short distance, the end organs of the palpi <!--[[palp]] and [[palpi]] redirect to [[pedipalp]], which pertain to Chelicerata, not insects, so don't link--> detect the odors.<ref name="Rat"/> Silphid beetles are usually more active at night, [[nocturnality|nocturnal]], which may help reduce competition.

===Competition===

[[Competition]] from other organisms for the [[carrion]] puts the silphids at both an advantage and a disadvantage. The advantage is that fly competitors lay eggs that result in [[maggot]]s and supply food for silphids. The disadvantage for the Nicrophorinae is that if the carcass is already “blown”, referring to [[Shakespeare]]an time as being infected with fly maggots, they will not colonize. Nicrophorinae have adapted to these situations and will bury the [[Carrion|carcass]] to remove it from other competitors.<ref>{{cite journal |vauthors=Eggert AK, Reinking M, Muller JK | year = 1998 | title = Parental Care Improves Offspring Survival and Growth in Burying Beetles | journal = Animal Behaviour | volume = 55 | issue = 1| pages = 97–107 | doi=10.1006/anbe.1997.0588| pmid = 9480676 | s2cid = 41821139 }}</ref> With this technique, a steady food source is available for the larvae and [[procreation]] chances increase.

Silphidae compete for [[offspring|brood]]ing areas. If an invader male overpowers the original male, it will mate with the original female and create a new [[offspring|brood]].<ref>{{cite journal | author = Trumbo ST | year = 2007 | title = Defending Young Biparentally: Female Risk-Taking with and Without a Male in the Burying Beetle, ''Nicrophorus pustulatus''| journal = Behavioral Ecology and Sociobiology | volume = 61 | issue = 11| pages = 1717–1723 | doi=10.1007/s00265-007-0403-5| s2cid = 26073189 }}</ref> If an invader female overpowers the original female, it will also create a new [[offspring|brood]] with the primary male.

==Relationships==

=== With humans===

Silphids are usually not considered a [[nuisance#Environmental nuisance|nuisance]] to humans. They help the environment by laying their eggs on [[Carrion|carcasses]] and the larvae break down the [[detritus]], which prevents accumulation of deceased organisms.

Carcasses are kept out of sight and foul odors are prevented when Nicrophorinae bury it under the ground. This will also reduce the surface area for flies to lay their eggs and decrease fly population.

Some Silphidae species inhabit human-occupied areas and become pests to farmers by using crops as an additional source of nutrients. In Europe, ''[[Aclypea opaca]]'' feeds on beets, while ''[[Necrophila americana]]'' feeds on pumpkins, spinach, and sugar beets.

===With other organisms===

Members from the family Silphidae are known to have mutualistic relationships with other organisms. Nicrophorinae have a mutual relationship with phoretic [[mite]]s. Mites from the genus ''[[Poecilochirus]]'' produce deutonymphs that crawl on Nicrophorinae and are transported to [[carrion]]. Once they arrive at the [[carrion]], deutonymphs leave the adult Nicrophorinae and proceed to feed on nearby fly eggs and immature [[larva]]e. Mites help Nicrophorinae reduce the number of competitors on [[carrion]]. With less competition, both species are able to reproduce successfully underground.<ref>{{cite journal | author = Grossman J.D. | author2 = Smith RJ | year = 2008 | title = Phoretic Mite Discrimination Among Male Burying Beetle (Nicrophorus Investigator) Hosts | journal = Annals of the Entomological Society of America | volume = 101 | issue = 1| pages = 266–271 | doi=10.1603/0013-8746(2008)101[266:pmdamb]2.0.co;2| doi-access = free }}</ref>

Silphidae are known for being hosts to juvenile [[nematode]]s. ''Nicrophorus vespilloides'' are closely associated with the [[nematode]] parasite. The parasites can be easily transmitted to other hosts during [[copulation (zoology)|copulation]].

==Forensic research==

Silphidae are one of several families of [[forensic science|forensic]] importance in the order [[Coleoptera]]. They are a very important tool in determining a [[post-mortem interval]] by collecting Silphid progeny from the [[Carrion|carcass]], and determining the developmental rate. Based on the number of instars and the larval development stage, a time of death can be estimated. This is very useful in [[Forensic entomology|medicocriminal entomology]], the emphasis on utilizing [[arthropod]]s as [[evidence]] to aid in solving crimes.<ref name="book"/> Many of the methods in determining stages of development are subjective. However, recent studies have found a more precise way of determining the stage of development of Silphid larvae by measuring the maximum cranial width and other heavily [[Sclerosis (medicine)|sclerotized]] areas of the larvae instead of measuring just the length, which is subject to change with each larva, particularly in ''O. inaequale'' and ''N. surinamensis'', which are more robust and have greater variations of length. The most accurate instar identification is possible by using distinct morphological features that are instar specific and cannot be affected by the size of the specimen. Although this is possible only for few species with described larvae of all instars, such as ''[[Thanatophilus rugosus]]''.<ref name="Nov">{{cite journal | author = Novák M. | author2 = Jakubec P. | author3 = Qubaiová J. Šuláková H. | author4 = Růžička J. | year = 2017 | title = Revisited larval morphology of Thanatophilus rugosus (Coleoptera: Silphidae) | journal = International Journal of Legal Medicine | volume = 2017| issue = 3| pages = 939–954| doi=10.1007/s00414-017-1764-6| pmid = 29270839 | s2cid = 206976798 }}</ref>

Silphidae are being studied to find more exact estimations of [[post-mortem interval]]s and possible manners of death.<ref name="Wat">{{cite journal | author = Watson E.J. | author2 = Carlton C.E. | doi = 10.1656/1528-7092(2005)004[0335:sofscb]2.0.co;2 | title = Succession of Forensically Significant Carrion Beetle Larvae on Large Carcasses (Coleoptera: Silphidae) | journal = Southeastern Naturalist | volume = 4 | year = 2005 | issue = 2| pages = 335–346 | s2cid = 86084430 }}</ref> Also, in the future, entomologists will explore the social behavior of the beetles to a greater degree. Members of family Silphidae are typically the first of the [[beetle|coleoptera]]ns to come in contact with [[carrion]]. Silphidae [[larva]]e are opportunistic [[predator]]s that will feed on [[fly|diptera]]n eggs, larvae, and on the carcass itself.<ref name="Wat"/> This presents a problem in the determination of post-mortem interval because Silphidae are known to eradicate other species from carrion. By eliminating the first colonizing species Silphidae can give an incorrect post-mortem interval.

Unlike most of the insects used as forensic markers, it is possible to assess if Silphidae adults have colonized a corpse and left it later. For this purpose, some [[Parasitidae]] mites (for example, ''Poecilochirus'' species) are used due to their phoront-host specificity. If a corpse is invaded by ''Poecilochirus'' specimens and no Silphidae were sampled by forensic entomologists, it is reasonable to suspect that some Silphidae carrying ''Poecilochirus'' phoretic instars arrived previously to the corpse and abandoned it some time later, leaving ''Poecilochirus'' mites in the process.<ref>{{cite journal |vauthors=González Medina A, González Herrera L, Perotti MA, Jiménez Ríos G | title=Occurrence of ''Poecilochirus austroasiaticus'' (Acari: Parasitidae) in forensic autopsies and its application on postmortem interval estimation | journal=Experimental and Applied Acarology | year=2013 | volume=59 | issue=3 | pages=297–305 | doi=10.1007/s10493-012-9606-1| pmid=22914911 | s2cid=16228053 }}</ref>

==References==
{{Reflist|2}}

==External links==
{{Commons category}}
{{Wikispecies|Silphidae}}
* [https://archive.org/details/synopsisofsilphi00horn Horn, GH (1880) Synopsis of the Silphidae of the United States with reference to the genera of other countries.]

<!-- not normal to use dropbox links
* [http://dl.getdropbox.com/u/1708278/Beetle%20News%20Vol%201_3%20reduced.pdf Beetle News] Beginner's Guide : Silphidae (Part 2) - Richard Wright (ISSN 2040-6177, October 2009).
-->

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[[Category:Silphidae| ]]
[[Category:Beetle families]]
[[Category:Staphylinoidea]]
[[Category:Taxa named by Pierre André Latreille]]
[[Category:Scavengers]]