Nicrophorus orbicollis
Encyclopedia
Nicrophorus orbicollis is a nearctic
burying beetle
first described by Thomas Say
in 1825. It is a member of the genus Nicrophorus or sexton beetles, comprising the most common beetles in the family Silphidae. This species is a decomposer feeding on carcasses of small dead animals. N. orbicollis can be used for scientific research both medically and forensically (if the beetle is present in the area).
with three orange apical
segments and a black base. The posterior lobe of the metepimeron has a few brown hairs and the hind tibia
is straight. The adult form is moderately sized at about 15-22mm (0.591"-0.866")long. N. orbicollis is known to be a saprophagous feeder. The adults feed on protein from smaller decomposing carcasses as well as supply these nutrients to their larvae.
sternal units called sternites.
and spread to southern parts of Pangea before the separation into Laurasia
and Gondwanaland. It is believed that Nicrophorus species originated in the Old World
and that most species related to N. orbicollis originated in Mexico and Central and South America.
s. Adults of the species are nocturnal. N. orbicollis is multivoltine
with adults that care for their offspring during larval development. N. orbicollis is distributed from southeastern Canada to the southern tip of Florida and to East Texas; it has also been discovered as far west as Nebraska and as far north as North Dakota. N. orbicollis is the most frequently collected silphid species in the eastern United States. Adults can be collected from February to October but are most commonly found during the summer months from June to August as a result of their efficient activity in warm weather. Most N. orbicollis have been collected in mesic
forest habitats on human and carnivore feces
as well as on rotten fruit and carrion
.
to attract a mate. If another male enters the area, the two males will fight to the death and the winner will claim the carcass. Some males have been known to try to attract a mate without providing a carcass
. These males will simply emit the pheromones even when they have not located a body. If females are attracted they will mate, but then continue to search for a mate that does have a carcass. Females are more likely to lay eggs fertilized by the most recent mate, so the males that have a carcass are more likely to actually pass on their genes
. Once a male attracts a female, the pair will proceed to bury the animal carcass together, equally sharing the workload. If the carcass is too big for one pair, then it is acceptable for multiple pairs to work together to bury the carcass. Eggs are laid and buried very close to the carcass to provide a nearby source of nourishment. Unlike most beetle species, N. orbicollis parents will provide both food and protection for the larvae until pupation. It has also been observed that if one parent is killed the other parent will double up on the feeding and protection duties so the larvae do not suffer. Without parental care the larvae cannot usually survive until the point of pupa
tion.
. Commonly seen riding on the elytra of N. orbicollis, the mites of genus Poecilochirus use the beetle as a source of transportaion. The two share a commensal relationship as the mites travels from carcass to carcass on the beetle in search for food. Fly eggs are generally the source of food for these mites, therefore, N.orbicollis does not compete with the mites in any form.
with complete metamorphosis
; the life cycle consists of an egg, larva
l, pupa
l, and adult stage. Male and female beetles are attracted to carrion
for reproduction and feeding. Male N. orbicollis attract females by emitting pheromones but they will only do so when a carcass is present. After mating, the female will lay her eggs from about 12–48 hours after discovering a suitable carcass. Eggs hatch around 56 hours after oviposition
. Once larva
e complete development they pupate in the soil in 6–8 days. The size of a carcass affects the time span an egg is laid to when the larvae disperse and so also affects the time frame the parent beetles spend taking care of their young. In general, the time spent from egg burial to larval dispersal is less on smaller carcasses. N. orbicollis males will also spend less time taking care of their offspring when on small carcasses. Larvae of most silphid species are dependent upon parental feeding but can sometimes feed directly from a carcass. N. orbicollis larvae, however, are extremely dependent upon their parents for feeding and will die before they develop to the second instar
without parental care. Offspring mass is positively correlated with longer maternal care. N. orbicollis is nocturnal and must compete with dipterous larvae for oviposition locations on carcasses.
carcasses to supply their young with an adequate food requirement. N. orbicollis mates mid-June to early August and is mostly active after sunset. First, the male attracts the female by producing pheromones. Competition occurs between other burying beetles and other carrion competitors to secure a carcass for mating. It is commonly seen that N. orbicollis will compete with N. defodiens. The larger in size the beetle, the more likely it is to outcompete smaller beetles in acquiring a carcass. Once the carcass has been secured and buried, the female lays her eggs in the soil surrounding the carcass. The larvae typically hatch 5–7 days later. Both the female and male have important roles as their larvae mature. Preservation of the carcass, protecting the larvae from predators
and feeding the larvae are all roles taken on by the adults. The males then disperse from the carcass once the larvae have reached the final instar
. The females will stay until the larvae disperse into the soil to pupate, usually 17 days after carcass burial.
Depending on the size of the carcass, the parents can control the number of offspring
through a process called filial cannibalism. The parents do this to allow more space on a smaller carcass.
. These beetles take a decomposing
carcass and turn it into nutrient
s for their larvae. They do this by burying a carcass (usually just two beetles, a male and a female) and feeding it to their young by regurgitation
. These beetles secrete an antibiotic
to delay decomposition in order to keep the competition away from the carcass so they will be able to feed their young.
There is little known about the medical importance of N. orbicollis. Their ability to recycle dead, decomposing
matter plays an indirect role in the health of the areas it inhabits. Natural antibiotics secreted by this beetle could potentially be medically beneficial in the future but currently nothing is known about the method of secretion.
have arrived and feed on the fly larvae. This feeding on fly larvae can jeopardize the accuracy of a post mortem interval estimation because these beetles can consume an entire population of fly larvae if they have a sufficient amount of time to do so. N. orbicollis can help determine the length of time a carcass has been present in a certain area if the beetle occurs in the region. Within 12–48 hours of discovering a carcass, the female will lay eggs, which will hatch approximately 56 hours later in desirable temperatures of 20–25 °C (68–77 F). N. orbicollis is unique in that it is a species in which the young are completely dependent upon their parents for survival. The adults bury the carcass to keep the tissue moist and to prevent it from being taken from them, and they feed their larvae the carcass through regurgitation
. After 5–8 days, the larvae will crawl into the surrounding soil to pupate and will emerge approximately 2 weeks later as adults. These timelines and the stages of the lifecycle of this beetle found on a carcass can all contribute to determining a time of death for forensic investigators.
habits, which have been found in no other genus
of beetles. This ensures that most future research will also be based on the evaluation of various specifics of the parental element in this species’ behavior. Other notable studies have been based on examining the competition for animal carcasses between N. orbicollis and other Nicrophorus species. However, one recent study in Ohio bred N. orbicollis in captivity
and then released the beetles back into the wild. This study was used to evaluate the success rate of reintroduction in order to plan for a possible future attempt at increasing the population through assisted means.
Nearctic
The Nearctic is one of the eight terrestrial ecozones dividing the Earth's land surface.The Nearctic ecozone covers most of North America, including Greenland and the highlands of Mexico...
burying beetle
Burying beetle
Burying beetles or sexton beetles are the best-known members of the family Silphidae . Burying beetles are true to their name. Most of these beetles are black with red markings on the elytra . They bury the carcasses of small vertebrates such as birds and rodents as a food source for their larvae...
first described by Thomas Say
Thomas Say
Thomas Say was an American naturalist, entomologist, malacologist, herpetologist and carcinologist. A taxonomist, he is often considered to be the father of descriptive entomology in the United States. He described more than 1,000 new species of beetles and over 400 species of insects of other...
in 1825. It is a member of the genus Nicrophorus or sexton beetles, comprising the most common beetles in the family Silphidae. This species is a decomposer feeding on carcasses of small dead animals. N. orbicollis can be used for scientific research both medically and forensically (if the beetle is present in the area).
Morphology/Taxonomy
Adult
N.orbicollis is immediately recognized by its colorful orange markings on its elytra. The dorsal surface of the elytra is covered in long, fine setae, especially laterally, giving it a hairy appearance. The pronotum is spherical with wide lateral and basal margins. Its most distinctive feature from other Silphidae is its clubbed antennaeAntenna (biology)
Antennae in biology have historically been paired appendages used for sensing in arthropods. More recently, the term has also been applied to cilium structures present in most cell types of eukaryotes....
with three orange apical
Apical
Apical, from the Latin apex meaning to be at the apex or tip, may refer to:*Apical , an anatomical term of location for features associated with the base of an organism or structure...
segments and a black base. The posterior lobe of the metepimeron has a few brown hairs and the hind tibia
Tibia
The tibia , shinbone, or shankbone is the larger and stronger of the two bones in the leg below the knee in vertebrates , and connects the knee with the ankle bones....
is straight. The adult form is moderately sized at about 15-22mm (0.591"-0.866")long. N. orbicollis is known to be a saprophagous feeder. The adults feed on protein from smaller decomposing carcasses as well as supply these nutrients to their larvae.
Larva
Larval N.orbicollis differ from other Silphidae by widely separated labial palpi. They also contain ten abdominal segments with the sternum separated into sclerotizedSclerosis (medicine)
In medicine, sclerosis refers to the stiffening of a structure, usually caused by a replacement of the normal organ-specific tissue with connective tissue.Types include:...
sternal units called sternites.
Origin
It is thought that silphids, including N. orbicollis, arose in the early MesozoicMesozoic
The Mesozoic era is an interval of geological time from about 250 million years ago to about 65 million years ago. It is often referred to as the age of reptiles because reptiles, namely dinosaurs, were the dominant terrestrial and marine vertebrates of the time...
and spread to southern parts of Pangea before the separation into Laurasia
Laurasia
In paleogeography, Laurasia was the northernmost of two supercontinents that formed part of the Pangaea supercontinent from approximately...
and Gondwanaland. It is believed that Nicrophorus species originated in the Old World
Old World
The Old World consists of those parts of the world known to classical antiquity and the European Middle Ages. It is used in the context of, and contrast with, the "New World" ....
and that most species related to N. orbicollis originated in Mexico and Central and South America.
Phenology and Distribution
N. orbicollis adults are active in the early spring with the first adult beetles emerging in late May. Reproduction occurs from June to August and teneral adults appear from late July to early August. This species spends the winter as an adult and is found mainly in open and forested habitatHabitat
* Habitat , a place where a species lives and grows*Human habitat, a place where humans live, work or play** Space habitat, a space station intended as a permanent settlement...
s. Adults of the species are nocturnal. N. orbicollis is multivoltine
Voltinism
Voltinism is a term used in biology to indicate the number of broods or generations of an organism in a year. The term is particularly in use in sericulture, where silkworm varieties vary in their voltinism....
with adults that care for their offspring during larval development. N. orbicollis is distributed from southeastern Canada to the southern tip of Florida and to East Texas; it has also been discovered as far west as Nebraska and as far north as North Dakota. N. orbicollis is the most frequently collected silphid species in the eastern United States. Adults can be collected from February to October but are most commonly found during the summer months from June to August as a result of their efficient activity in warm weather. Most N. orbicollis have been collected in mesic
Mesic habitat
In ecology, a mesic habitat is a type of habitat with a moderate or well-balanced supply of moisture, e.g., a mesic forest, a temperate hardwood forest, or dry-mesic prairie. Compared to a dry habitat, a mesic habitat is moister....
forest habitats on human and carnivore feces
Feces
Feces, faeces, or fæces is a waste product from an animal's digestive tract expelled through the anus or cloaca during defecation.-Etymology:...
as well as on rotten fruit and carrion
Carrion
Carrion refers to the carcass of a dead animal. Carrion is an important food source for large carnivores and omnivores in most ecosystems. Examples of carrion-eaters include vultures, hawks, eagles, hyenas, Virginia Opossum, Tasmanian Devils, coyotes, Komodo dragons, and burying beetles...
.
Behavior
N.orbicollis males will search for small bodies of animals such as chipmunks, rabbits, and toads in which to attract a mate. Once a body is located the male will proceed to climb onto the carcass and emit a pheromonePheromone
A pheromone is a secreted or excreted chemical factor that triggers a social response in members of the same species. Pheromones are chemicals capable of acting outside the body of the secreting individual to impact the behavior of the receiving individual...
to attract a mate. If another male enters the area, the two males will fight to the death and the winner will claim the carcass. Some males have been known to try to attract a mate without providing a carcass
Carrion
Carrion refers to the carcass of a dead animal. Carrion is an important food source for large carnivores and omnivores in most ecosystems. Examples of carrion-eaters include vultures, hawks, eagles, hyenas, Virginia Opossum, Tasmanian Devils, coyotes, Komodo dragons, and burying beetles...
. These males will simply emit the pheromones even when they have not located a body. If females are attracted they will mate, but then continue to search for a mate that does have a carcass. Females are more likely to lay eggs fertilized by the most recent mate, so the males that have a carcass are more likely to actually pass on their genes
Gênes
Gênes is the name of a département of the First French Empire in present Italy, named after the city of Genoa. It was formed in 1805, when Napoleon Bonaparte occupied the Republic of Genoa. Its capital was Genoa, and it was divided in the arrondissements of Genoa, Bobbio, Novi Ligure, Tortona and...
. Once a male attracts a female, the pair will proceed to bury the animal carcass together, equally sharing the workload. If the carcass is too big for one pair, then it is acceptable for multiple pairs to work together to bury the carcass. Eggs are laid and buried very close to the carcass to provide a nearby source of nourishment. Unlike most beetle species, N. orbicollis parents will provide both food and protection for the larvae until pupation. It has also been observed that if one parent is killed the other parent will double up on the feeding and protection duties so the larvae do not suffer. Without parental care the larvae cannot usually survive until the point of pupa
Pupa
A pupa is the life stage of some insects undergoing transformation. The pupal stage is found only in holometabolous insects, those that undergo a complete metamorphosis, going through four life stages; embryo, larva, pupa and imago...
tion.
Interaction with mites
N.orbicollis are sometimes seen interacting with other arthropods such as the mites of PoecilochirusPoecilochirus
Poecilochirus is a genus of mites in the family Parasitidae. They feed on fly eggs and larva. At least 14 species of the genus are carried from one food source to another by beetles of multiple genuses in the family Silphidae with whom they often have a symbiotic relationship in protecting the...
. Commonly seen riding on the elytra of N. orbicollis, the mites of genus Poecilochirus use the beetle as a source of transportaion. The two share a commensal relationship as the mites travels from carcass to carcass on the beetle in search for food. Fly eggs are generally the source of food for these mites, therefore, N.orbicollis does not compete with the mites in any form.
Life cycle
N. orbicollis is an endopterygoteEndopterygota
The Endopterygota, also known as Holometabola, are insects of the subclass Pterygota which go through distinctive larval, pupal, and adult stages. They undergo a radical metamorphosis, with the larval and adult stages differing considerably in their structure and behaviour...
with complete metamorphosis
Holometabolism
Holometabolism, also called complete metamorphism, is a term applied to insect groups to describe the specific kind of insect development which includes four life stages - as an embryo or egg, a larva, a pupa and an imago or adult. Holometabolism is a monophyletic trait that all insects in the...
; the life cycle consists of an egg, larva
Larva
A larva is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle...
l, pupa
Pupa
A pupa is the life stage of some insects undergoing transformation. The pupal stage is found only in holometabolous insects, those that undergo a complete metamorphosis, going through four life stages; embryo, larva, pupa and imago...
l, and adult stage. Male and female beetles are attracted to carrion
Carrion
Carrion refers to the carcass of a dead animal. Carrion is an important food source for large carnivores and omnivores in most ecosystems. Examples of carrion-eaters include vultures, hawks, eagles, hyenas, Virginia Opossum, Tasmanian Devils, coyotes, Komodo dragons, and burying beetles...
for reproduction and feeding. Male N. orbicollis attract females by emitting pheromones but they will only do so when a carcass is present. After mating, the female will lay her eggs from about 12–48 hours after discovering a suitable carcass. Eggs hatch around 56 hours after oviposition
Oviposition
Oviposition is the process of laying eggs by oviparous animals.Some arthropods, for example, lay their eggs with an organ called the ovipositor.Fish , amphibians, reptiles, birds and monetremata also lay eggs....
. Once larva
Larva
A larva is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle...
e complete development they pupate in the soil in 6–8 days. The size of a carcass affects the time span an egg is laid to when the larvae disperse and so also affects the time frame the parent beetles spend taking care of their young. In general, the time spent from egg burial to larval dispersal is less on smaller carcasses. N. orbicollis males will also spend less time taking care of their offspring when on small carcasses. Larvae of most silphid species are dependent upon parental feeding but can sometimes feed directly from a carcass. N. orbicollis larvae, however, are extremely dependent upon their parents for feeding and will die before they develop to the second instar
Instar
An instar is a developmental stage of arthropods, such as insects, between each molt , until sexual maturity is reached. Arthropods must shed the exoskeleton in order to grow or assume a new form. Differences between instars can often be seen in altered body proportions, colors, patterns, or...
without parental care. Offspring mass is positively correlated with longer maternal care. N. orbicollis is nocturnal and must compete with dipterous larvae for oviposition locations on carcasses.
Reproduction
N. orbicollis depends on small vertebrateVertebrate
Vertebrates are animals that are members of the subphylum Vertebrata . Vertebrates are the largest group of chordates, with currently about 58,000 species described. Vertebrates include the jawless fishes, bony fishes, sharks and rays, amphibians, reptiles, mammals, and birds...
carcasses to supply their young with an adequate food requirement. N. orbicollis mates mid-June to early August and is mostly active after sunset. First, the male attracts the female by producing pheromones. Competition occurs between other burying beetles and other carrion competitors to secure a carcass for mating. It is commonly seen that N. orbicollis will compete with N. defodiens. The larger in size the beetle, the more likely it is to outcompete smaller beetles in acquiring a carcass. Once the carcass has been secured and buried, the female lays her eggs in the soil surrounding the carcass. The larvae typically hatch 5–7 days later. Both the female and male have important roles as their larvae mature. Preservation of the carcass, protecting the larvae from predators
Predation
In ecology, predation describes a biological interaction where a predator feeds on its prey . Predators may or may not kill their prey prior to feeding on them, but the act of predation always results in the death of its prey and the eventual absorption of the prey's tissue through consumption...
and feeding the larvae are all roles taken on by the adults. The males then disperse from the carcass once the larvae have reached the final instar
Instar
An instar is a developmental stage of arthropods, such as insects, between each molt , until sexual maturity is reached. Arthropods must shed the exoskeleton in order to grow or assume a new form. Differences between instars can often be seen in altered body proportions, colors, patterns, or...
. The females will stay until the larvae disperse into the soil to pupate, usually 17 days after carcass burial.
Depending on the size of the carcass, the parents can control the number of offspring
Offspring
In biology, offspring is the product of reproduction, of a new organism produced by one or more parents.Collective offspring may be known as a brood or progeny in a more general way...
through a process called filial cannibalism. The parents do this to allow more space on a smaller carcass.
Economic and Medical
N. orbicollis have not been found to have a direct effect on the economy. This species does, however, play a very important role in recyclingRecycling
Recycling is processing used materials into new products to prevent waste of potentially useful materials, reduce the consumption of fresh raw materials, reduce energy usage, reduce air pollution and water pollution by reducing the need for "conventional" waste disposal, and lower greenhouse...
. These beetles take a decomposing
Decomposition
Decomposition is the process by which organic material is broken down into simpler forms of matter. The process is essential for recycling the finite matter that occupies physical space in the biome. Bodies of living organisms begin to decompose shortly after death...
carcass and turn it into nutrient
Nutrient
A nutrient is a chemical that an organism needs to live and grow or a substance used in an organism's metabolism which must be taken in from its environment. They are used to build and repair tissues, regulate body processes and are converted to and used as energy...
s for their larvae. They do this by burying a carcass (usually just two beetles, a male and a female) and feeding it to their young by regurgitation
Regurgitation (digestion)
Regurgitation is the expulsion of material from the mouth, pharynx, or esophagus, usually characterized by the presence of undigested food or blood.Regurgitation is used by a number of species to feed their young...
. These beetles secrete an antibiotic
Antibiotic
An antibacterial is a compound or substance that kills or slows down the growth of bacteria.The term is often used synonymously with the term antibiotic; today, however, with increased knowledge of the causative agents of various infectious diseases, antibiotic has come to denote a broader range of...
to delay decomposition in order to keep the competition away from the carcass so they will be able to feed their young.
There is little known about the medical importance of N. orbicollis. Their ability to recycle dead, decomposing
Decomposition
Decomposition is the process by which organic material is broken down into simpler forms of matter. The process is essential for recycling the finite matter that occupies physical space in the biome. Bodies of living organisms begin to decompose shortly after death...
matter plays an indirect role in the health of the areas it inhabits. Natural antibiotics secreted by this beetle could potentially be medically beneficial in the future but currently nothing is known about the method of secretion.
Forensic
The species has proven to be forensically important as well because it does not show up on the carcass until this has been exposed for several days. N. orbicollis show up after fliesFließ
Fließ is a municipality in the Landeck district and is located5 km south of Landeck on the upper course of the Inn River. It has 9 hamlets and was already populated at the roman age; the village itself was founded around the 6th century. After a conflagration in 1933 Fließ was restored more...
have arrived and feed on the fly larvae. This feeding on fly larvae can jeopardize the accuracy of a post mortem interval estimation because these beetles can consume an entire population of fly larvae if they have a sufficient amount of time to do so. N. orbicollis can help determine the length of time a carcass has been present in a certain area if the beetle occurs in the region. Within 12–48 hours of discovering a carcass, the female will lay eggs, which will hatch approximately 56 hours later in desirable temperatures of 20–25 °C (68–77 F). N. orbicollis is unique in that it is a species in which the young are completely dependent upon their parents for survival. The adults bury the carcass to keep the tissue moist and to prevent it from being taken from them, and they feed their larvae the carcass through regurgitation
Regurgitation (digestion)
Regurgitation is the expulsion of material from the mouth, pharynx, or esophagus, usually characterized by the presence of undigested food or blood.Regurgitation is used by a number of species to feed their young...
. After 5–8 days, the larvae will crawl into the surrounding soil to pupate and will emerge approximately 2 weeks later as adults. These timelines and the stages of the lifecycle of this beetle found on a carcass can all contribute to determining a time of death for forensic investigators.
Future Research
In the past few years, most research on N. orbicollis has been centered on the species’ unique parentingParenting
Parenting is the process of promoting and supporting the physical, emotional, social, and intellectual development of a child from infancy to adulthood...
habits, which have been found in no other genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of beetles. This ensures that most future research will also be based on the evaluation of various specifics of the parental element in this species’ behavior. Other notable studies have been based on examining the competition for animal carcasses between N. orbicollis and other Nicrophorus species. However, one recent study in Ohio bred N. orbicollis in captivity
Captivity (animal)
Animals that live under human care are in captivity. Captivity can be used as a generalizing term to describe the keeping of either domesticated animals or wild animals. This may include for example farms, private homes and zoos...
and then released the beetles back into the wild. This study was used to evaluate the success rate of reintroduction in order to plan for a possible future attempt at increasing the population through assisted means.
External links
- https://www.msu.edu/user/miller20/ebert.htm
- http://beheco.oxfordjournals.org/cgi/content/full/10/5/578
- http://findarticles.com/p/articles/mi_qa3845/is_200201/ai_n9035920/
- http://www.insectsofwestvirginia.net/b/nicrophorus-orbicollis.html
- http://bugguide.net/node/view/32197