Carrion beetle

from Wikipedia, the free encyclopedia
Carrion beetle
Black-horned gravedigger (Nicrophorus vespilloides)

Black-horned gravedigger (Nicrophorus vespilloides)

Systematics
Class : Insects (Insecta)
Order : Beetle (Coleoptera)
Subordination : Polyphaga
Partial order : Staphyliniformia
Superfamily : Staphylinoidea
Family : Carrion beetle
Scientific name
Silphidae
Latreille , 1807
Subfamilies

The carrion beetles (Silphidae) are a family of beetles . Up to 2008, 183 species had been described worldwide, but new species are still being added every year.

features

The carrion beetles are 7 to 45 millimeters long, but most species are between 12 and 20 millimeters long. The body shape is usually more or less elongated oval, it is clearly (Silphinae) or slightly flattened (Nicrophorinae). Most species are colored black (exception: Dendroxena ), many with striking red or orange spots or bandages. The body is usually shiny and only slightly dotted and usually sparsely haired.

The head is stretched forward or sits slightly drooping under the large pronotum. Two hemispherical protruding complex eyes sit on it. The antennae are eleven-limbed, whereas those of the subfamily Nicrophorinae appear ten-limbed (second and third antenna segments fused). The last three antennae-segments form a separate club, which in the Silphinae are not shiny like the rest of the antennae, but are strikingly matt. In the genus Nicrophorus , the club is divided into individual leaves.

The throat plate (pronotum) is always large and flattened and margins on the sides; mostly it is as wide as the wing-coverts. The large scutellum , which can be as wide as the head, is also striking and very characteristic of the family . In most of the Silphinae the elytra cover the entire abdomen; in the genera Diamesus , Necrodes and all Nicrophorinae, however, they are shortened and leave one to five tergites of the abdomen free. Most species have fully developed hind wings and are able to fly, but there are individual species with shortened hind wings. The sides of the cover wings are folded down. The part sitting on the sides of the body is delimited by a keel; these lateral sections are called epipleurs. As a rule, there are three prominent longitudinal keels on the disc of the wing cover ( very indistinct in Nicrophorus and Ablattaria ), but the stripes or rows of dots characteristic of many families of beetles are completely absent. At the end of the outermost keel there is a conspicuous bump; this is the only known autapomorphism in the family. The strong legs have five-segment tarsi . In the males, the limbs of the anterior tarsi are usually clearly widened (they serve to hold on to the female at the copula).

The first segment in the abdomen cannot be seen; the second is hidden by the hind hips but is visible on the side. The sternites three to eight, in the male three to nine, are clearly recognizable. In the subfamily Nicrophorinae, longitudinal grooves sit on the fifth tergite. The animals can create sounds by rubbing their elytra over them ( stridulation ).

Larvae

The shape of the larvae is very different between the two subfamilies. The larvae are elongated and 12 to 40 millimeters long. In the Nicrophorinae they are cylindrical and parallel-sided, only slightly sclerotized and predominantly whitish. In the Silphinae they are mostly very flattened, narrowed towards the back and clearly sclerotized on the upper side and usually extensively black in color, often with light markings. This larval form is described as "slice-shaped". The head is protruding (prognath), it has six in the Silphinae and only one larval eye (Stemma or Ocellus) in the Nicrophorinae. The tripartite antennae are usually relatively long. The mandibles are large and single or multi-pointed without chewing surfaces. Three relatively long pairs of five-limbed legs sit on the thorax. The abdomen consists of ten segments, with two short, two-part appendages at the end, which are called urogomphi.

The carrion beetles have three larval stages. The way of life of the larvae is clearly different. The larvae of the Silphinae are free living and feed themselves independently. Those of the Nicrophorinae sit in a nest built and provided by the parent animals, they are usually fed by the mother (brood care, see below). Due to the mostly very energetic food (mainly carrion, see below), youth growth is very rapid. In the species examined, the duration of embryonic development was approx. 5 to 6 days. The three larval stages are completed in about 20 to 30 days. There are also eight to ten days of doll rest. In many species, however, the final larval stage (then called “prepupa”), ready to transform, digs a hole in the ground and hibernates in it.

distribution

The family is mainly found in the temperate (temperate) northern latitudes, both in Eurasia ( Palearctic ) and in North America ( Nearctic ). In the tropics they are rare, they occur with some species in mountain regions, but are almost absent in the lowlands (here they are replaced by representatives of the Scarabaeidae family with a very similar way of life). Three species live in Australia and also in South Africa. Three species of the endemic genus Heterotemna occur exclusively in the Canary Islands. It is striking that carrion beetles are almost completely absent in dry habitats such as B. Deserts. They are particularly species-rich in forests and grasslands, including cultivated land.

Way of life

nutrition

Most of the species in the family are primarily scavengers , both as beetles (imago) and as larvae . In addition to the corpses, mostly of vertebrates themselves, most species also eat other animals living on carrion, especially fly maggots, and are therefore sometimes predatory. A number of species, particularly in the subfamily Silphinae, have passed from carrion to other food sources. Most of the species in the Nicrophorinae subfamily specialize in the corpses of small vertebrates such as mice or songbirds. Unique is the North American species Nicrophorus pustulatus , which (in addition to a widespread use of carrion) penetrates snake nests and uses the snake eggs as a food source for the larvae. A number of species in the Silphinae subfamily are predators with no relation to carrion. Notably, most predatory species are incapable of flight, while most carrion-bound species can fly well. This is explained by the peculiarities of the carrion resource: It is a very high quality food source, but it is seldom and unpredictably distributed in the habitat and faces very strong competition from other beetles of the same and other species, from other insects such as B. flies and vertebrates, is subject. Therefore, carrion-consuming species have a great advantage if they reach a food object very quickly, if possible first.

A number of species are relatively unspecialized in nutrition; in addition to carrion, they can also use other nutrient-rich organic substances, both of vegetable and animal origin; this applies to many Silpha species. Oiceoptoma thoracicum has developed the fruiting bodies of mushrooms as an additional food source, especially stink morels . The four-point carrion beetle ( Dendroxena quadrimaculata ) eats live prey, including caterpillars . Phosphuga atrata is a specialized hunter of shell snails. The species of the genus Aclypea are phytophagous (herbivores), Aclypea opaca is known as an agricultural pest on beets.

Social behavior: The genus Nicrophorus

The grave diggers ( Nicrophorus spec. ) Are especially known for their extremely interesting brood care behavior . Nicrophorus , which is a dead small vertebrate, e.g. B. a mouse, have discovered, try to monopolize it for themselves. To do this, they fight other Nicrophorus on the same carcass, both their own and other species. As a rule, the individuals with the largest body size win. In the end there is a pair of particularly large beetles left. These chew the carcass, remove hair or feathers and process it until it has become a shapeless ball, glandular secretions are also incorporated. At the same time, they scrape away the soil under the corpse and gradually bury the animal in the soil, where they construct a brood chamber with sturdy walls. These activities are carried out at the greatest possible speed in order to forestall potential competitors who may arrive later. If an animal's corpse is already heavily infested with fly maggots, it is usually no longer used by Nicrophorus . There are indications that ( phoretic ) mite species brought along as “passengers” help the beetles , which prefer to feed on fly eggs ( mutualism ). Only in the finished brood chamber does mating finally take place. Then the female lays what is usually a relatively small clutch of eggs into the ground. The hatching larvae migrate to the food ball. Here they gather in a small pit created by the parent animals, usually on the top. The parent animals, but especially the female, take care of the young and feed them with choked, pre-digested food pulp. The food ball is also cared for and treated with secretion, which is important to prevent the emergence of harmful fungi. The father usually leaves the nest at this stage, sometimes driven away by the mother. Obviously, the pups don't benefit much from his presence. The main purpose of his stay behind is to deny entry to other males, who might kill the young larvae and raise a new brood of their own offspring with the female. The adult larvae finally continue to eat without the help of their mother, usually until the food ball is completely used up. Since their body size is variable and depends on the diet, and large animals have a strong competitive advantage (see above), they particularly benefit from growth in size, also at the expense of the speed of development. Usually the three larval stages last a few weeks. Afterwards, the adult larvae, ready to pupate, dig themselves a cave in which, depending on the season, they either overwinter or pupate immediately.

The beetles are able to recognize their respective partners from intruders of the same species into the breeding chamber, who want to take over the nest or at least want to benefit from it as breeding parasites without their own contribution. In doing so, they recognize less the partner itself than the reproductive status in which a beetle is currently located. The hydrocarbon patterns in the waxy outer layer of the exoskeleton , the epicuticle, serve as markers . Once foreign larvae are present in the nesting chamber, the beetles cannot distinguish them from their own offspring. Brood parasitism is therefore widespread. If a carrion is too big for one couple to be able to drive away all competitors, another couple often establishes itself on the food ball. These lay eggs, but do not take part in brood care. An East Asian species, Ptomascopus morio , is even an obligatory brood parasite in Nicrophorus species and no longer creates its own brood nests.

Although in principle all Nicrophorus species have a comparable lifestyle, several, often three to five, different species can usually be found next to each other in a given habitat. The competition between species that occur together is very intense and often leads to the exclusion of competitive species. They can then coexist with one another if they each have special features in life cycle and way of life, i.e. if they are ecologically mixed with one another . The types differ z. B. in the season of their occurrence, in the main activity period in the daily cycle, in the size of the preferred animal corpses. Habitats with hard, dry soils can only be used by large species because small beetles here do not have enough strength to dig their breeding caves.

Forensic entomology

In the succession to vertebrate corpses, carrion beetles usually belong to the second wave of colonization after blowflies and meat flies. Although they could be used in forensic entomology to determine the time and circumstances of death of human corpses, they are usually not used for this today. The main reason for this is that they are less common in houses and apartments than flies. In addition, little research has been done on them in this regard.

Systematics

The affiliation of the carrion beetles to the Staphylinoidea is well secured by numerous characteristics. Your position has not yet been clarified with absolute certainty. In most of the studies, they were regarded as the sister group of the Staphylinidae (in the broader sense, including the earlier families Scydmaenidae and Scaphidiidae), but some studies also suggest a position within the rove beetles (which would then be paraphyletic). Recent studies (e.g.) tend to support the hypothesis of a sister group relationship. The Silphidae are divided into the two well characterizable subfamilies Silphinae and Nicrophorinae (in older literature often still called Necrophorinae), which are better secured than the family itself by numerous autapomorphies. In the past, the Agyrtinae were regarded as the third subfamily, which is now an independent family Agyrtidae be valid. The position of the Agyrtidae is not clear, they are probably not a sister group of the Silphidae. While the subfamily Silphinae includes at least twelve genera, a large part of the Nicrophorinae belongs to the genus Nicrophorus . Only two other, species-poor genera are known ( Eonecrophorus and Ptomascopus with a total of three species), both of which live in East Asia.

In Europe , both subfamilies with a total of ten genera and 47 species are known, in Central Europe there are 30 species, on the British Isles there are 21.

Family Silphidae (carrion beetles)

Subfamily Nicrophorinae

Genus gravedigger ( Nicrophorus )

Subfamily Silphinae

Black snail hunter ( Phosphuga atrata )

credentials

  1. ↑ a b c Derek S. Sikes (2008): Carrion beetles (Coleoptera: Silphidae). In: JL Capinera (editor) Encyclopedia of entomology. Dordrecht, The Netherlands (Springer): 749-757.
  2. ↑ a b c d Derek S. Sikes (2005): Silphidae Latreille, 1807. In: NP Kristensen & RG Beutel (editors): Handbook of Zoology. Vol. 4: Arthropoda: Insecta. Berlin (Walter de Gruyter): 288-296.
  3. ^ Bernhard Klausnitzer: 19th family: Silphidae. In: B. Klausnitzer (1997): (Editor): The larvae of the beetles of Central Europe. 4th volume, Polyphaga, part 3. Jena (Gustav Fischer). Pages 39–65
  4. ↑ Ilkka Hanski (1987): Nutritional ecology of dung- and carrion-feeding insects. In: F. Slansky jr. & JG Rodriguez (editors): Nutritional ecology of insects, mites, spiders and related invertebrates. (John Wiley): 837-884.
  5. ↑ Stewart B. Peck (2001): Review of the Carrion beetles of Australia and New Guinea (Coleoptera: Silphidae). Australian Journal of Entomology 40: 93-101.
  6. ↑ G. Smith, ST Trumbo, DS Sikes, MP Scotts, RL Smith (2007): Host shift by the burying beetle, Nicrophorus pustulatus, a parasitoid of snake eggs. Journal of Evolutionary Biology 20: 2389-2399. doi : 10.1111 / j.1420-9101.2007.01404.x
  7. ↑ Hiroshi Ikeda, Takashi Kagaya, Kohei Kubota, Toshio Abe (2008): Evolutionary relationships among food habit, loss of flight, and reproductive traits: life-history evolution in the Silphinae (Coleoptera: Silphidae). Evolution 62 (8): 2065-2079. doi : 10.1111 / j.1558-5646.2008.00432.x
  8. ↑ R. Heymons, H. v. Lengerken (1931): Studies on the life phenomena of the Silphini (Coleoptera): VII: Oeceoptoma thoracica L. In: Journal for Morphology and Ecology of Animals 20 (4): 691-706.
  9. ↑ R. Heymons, H. v. Lengerken, Marg Bayer (1928): Studies on the life phenomena of the Silphini (Coleopt.). III. Xylodrepa quadripunctata L. In: Journal for Morphology and Ecology of Animals 10 (2/3): 330-352.
  10. ↑ R. Heymons, H. v. Lengerken, Marg Bayer (1927): Studies on the life phenomena of the Silphini (Coleoptera): II. Phosphuga atrata L. In: Journal for Morphology and Ecology of Animals 9 (1/2): 271-312.
  11. ↑ HH Schwarz, M. Starrachs, S. Koulianos (1998): Host specificity and permanence of associations between mesostigmatic mites (Acari: Anactinotrichida) and burying beetles (Coleoptera: Silphidae: Nicrophorus. Journal of Natural History 32: 159-172 )
  12. ↑ Josef K. Müller, Anne-Katrin Eggert, Scott K. Sakaluk (1998): Carcass maintenance and biparental brood care in burying beetles: Are males redundant? Ecological Entomology 23: 195-200.
  13. ↑ Sandra Steiger Steiger. 2010. Evolution of chemical communication: What we can learn from the gravedigger. In: Steinbrecht, RA (Ed.): Zoologie 2010 - Mitteilungen der Deutschen Zoologischer Gesellschaft, pp. 9-14. Basilisk Press Rangsdorf.
  14. ↑ Sandra Steiger, Ragna Franz, Anne-Katrin Eggert, Josef K. Müller (2008): The Coolidge effect, individual recognition and selection for distinctive cuticular signatures in a burying beetle. Proceedings of the Royal Society Series B 275: 1831-1838. doi : 10.1098 / rspb.2008.0375
  15. ↑ Stephen T. Trumbo, Masahiro Kon, Derek Sikes (2001): The reproductive biology of Ptomascopus morio, a brood parasite of Nicrophorus. Journal of Zoology, London 255: 543-560.
  16. ↑ David Sloane Wilson, WG Knollenberg, J. Fudge (1984): Species packing and temperature dependent competition among burying beetles (Silphidae, Nicrophorus). Ecological Entomology 9: 205-216.
  17. ↑ Michelle Pellissier Scott (1998): The ecology and behavior of Burying Beetles. Annual Revue of Entomology 43: 595-618.
  18. ↑ Jessica Dekeirsschieter, François Verheggen, Georges Lognay, Eric Haubruge (2011): Large carrion beetles (Coleoptera, Silphidae) in Western Europe: a review. Biotechnology, Agronomy, Society and Environment (BASE) 15 (3): 435-447.
  19. ^ Vasily V. Grebennikov & Alfred F. Newton (2009): Good-bye Scydmaenidae, or why the ant-like stone beetles should become megadiverse Staphylinidae sensu latissimo (Coleoptera). European Journal of Entomology 106: 275-301 (p.288)
  20. ↑ Silphidae. Fauna Europaea, accessed May 1, 2007 .

literature

  • H. Joy: Silphidae: In: H. Joy, KW Harde & GA Lohse (Ed.): Die Käfer Mitteleuropas. Volume 3. Staphylinoidea; Fam. Silphidae, Catopidae, Liodidae, Scydmaenidae, Ptilidae, Scaphididae, 1971, pp. 190-201.
  • GV Portevin: Les Grands Necrophages du Globe: Silphini - Necrodini - Necrophorini. - Encyclopédie entomologique, Série A, Travaux généraux, 6, 1926, pp. 1-270.
  • James T. Costa: The Other Insect Societies. (Belknap Press). Inside: Carrion beetles. Silphidae: Nicrophorinae. 2006, p. 427 ff.

Web links

Commons : Carrion Beetles (Silphidae)  - Collection of images, videos and audio files
Wiktionary: carrion beetle  - explanations of meanings, word origins, synonyms, translations
Wikisource Wikisource: Aaskäfer  - Article of the 4th edition of Meyers Konversations-Lexikon