scarab beetle
The family Scarabaeidae, as currently defined, consists of over 30,000 species of beetles worldwide; they are often called scarabs or scarab beetles. The classification of this family has undergone significant change in recent years. Several sub ...
species
In biology, a species is the basic unit of Taxonomy (biology), classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of ...
collectively called true dung beetles. Most of the beetles of this subfamily feed exclusively on dung. However, some may feed on decomposing matter including carrion, decaying fruits and fungi. Dung beetles can be placed into three structural guilds based on their method of dung processing namely rollers, dwellers and tunnelers Dung removal and burial by dung beetles result in ecological benefits such as soil aeration and fertilization; improved nutrient cycling and uptake by plants, increase in Pasture quality, biological control of pest flies and intestinal parasites and secondary seed dispersal. Well-known members include the genera '' Scarabaeus'' and ''
Sisyphus
In Greek mythology, Sisyphus or Sisyphos (; Ancient Greek: Σίσυφος ''Sísyphos'') was the founder and king of Ephyra (now known as Corinth). Hades punished him for cheating death twice by forcing him to roll an immense boulder up a hill ...
'', and ''
Phanaeus vindex
''Phanaeus vindex'', the rainbow scarab, is a North American dung beetle, found from the eastern US to Arizona and Mexico. The head is a metallic yellow color, and males have a black horn which curves backward toward the thorax. Both sexes have ...
''.
Description
Adult dung beetles have modified mouth parts which are adapted to feeding on dung. The clypeus is expanded and covers the mouth parts. The
elytra
An elytron (; ; , ) is a modified, hardened forewing of beetles (Coleoptera), though a few of the true bugs ( Hemiptera) such as the family Schizopteridae are extremely similar; in true bugs, the forewings are called hemelytra (sometimes altern ...
, which cover the wings, expose the
pygidium
The pygidium (plural pygidia) is the posterior body part or shield of crustaceans and some other arthropods, such as insects and the extinct trilobites. In groups other than insects, it contains the anus and, in females, the ovipositor. It is com ...
. They also have a space between their middle legs to allow for manipulation of the dung. Dung beetles can be large beetles of a few inches in size to small beetles which are only a few millimeters in size
Guilds
Dung beetles are classified into groups based on their method of processing the dung. Rollers are beetles that construct balls of dung from the main food source. They roll away this ball from the position of the original food source and use the dung for feeding or for reproduction. Tunnelers are beetles that dig tunnels beneath the food source creating nests. They relocate food into their nest for reproduction and feeding. Lastly, dwellers are beetles that live and reproduce inside the food source rarely creating nests.
Reproduction
Pheromones are thought to aid in dung beetle reproduction. Dung beetles copulate after which both parents dig a tunnel to lay the eggs. This tunnel may have different branches leading to varying egg chambers or may not be branched depending on species. Both parents take dung inside the tunnels in the form of brood balls and the females lay the egg inside the dung. When the larva hatches it feeds on the surrounding dung and forms a pupa undergoing several instars. After this stage the pupa hatches and the newly formed adult evades the tunnel and searches for a fresh dung supply for feeding. After approximately 2 weeks the new adult beetle will be able to reproduce.
Ecology
Dung beetle communities are dependent on vegetation and presence of mammalian dung resource. In an area with a lot of vegetation, the dung pads are preserved longer for dung beetle utilization. Vegetation provides conditions suitable for vertebrate trafficking allowing more dung presence in the area. In areas with little vegetation, limited vertebrate fauna may be present limiting the types of dung present. Also, with little vegetation the canopy of the forest may be limiting. This causes the dung pads to be exposed to sunlight, higher temperature and wind action. These factors contribute to dung pad desiccation which decreases the period of suitable dung availability. Dung beetles of different groups may respond to changes in vegetation in different ways.
A decline in dung beetle diversity associated with the conversion of native forests to open pastures is known to occur. However, some species are able to utilize dung in open pasture conditions. Tunneler species are able to utilize dung in less optimal condition because the tunnel beneath the dung and utilize it from bottom up. As desiccation occurs on the top of the dung pad, the middle and lower regions may still be suitable for the dung beetle. Also, smaller species are able to survive in such conditions as they require less dung. Larger beetles require larger amounts of dung which may not be available due to the fast desiccation of the dung pads in these conditions. Soil hardness and dryness negatively affect the tunnelers. Species able to tolerate open pasture conditions were extremely abundant. The reduction in the number of dung beetles affected the efficiency of their ecological roles and it was found that dung removal and burial declined. Dung removal and burial by dung beetles result in ecological benefits such as soil aeration and fertilization. These benefits lead to improved nutrient cycling and uptake by plants, increase in pasture quality, biological control of pest flies and intestinal parasites and secondary seed dispersal. Therefore, their role in the ecosystem is essential.
Taxonomy
The subfamily is split into about 12
extant
Extant is the opposite of the word extinct. It may refer to:
* Extant hereditary titles
* Extant literature, surviving literature, such as ''Beowulf'', the oldest extant manuscript written in English
* Extant taxon, a taxon which is not extinct, ...
tribe
The term tribe is used in many different contexts to refer to a category of human social group. The predominant worldwide usage of the term in English is in the discipline of anthropology. This definition is contested, in part due to confl ...
s. These can be grouped by their distribution, though the present classification is expected to require major revision based on recent phylogenetic analyses.
Coprini
Coprini is a tribe of scarab beetles, in the dung beetle subfamily ( Scarabaeinae). Scholtz et al. describe them as tunnellers that are shiny black, of moderate to large size (9–30 mm long) and with a strongly convex shape. They also, ho ...
(incl. Dichotomiini) - about 20 genera including:
** '' Copris'' Geoffroy, 1762
** ''
Dichotomius
''Dichotomius'' is a genus of Scarabaeidae or scarab beetles in the superfamily Scarabaeoidea.
Species
* '' Dichotomius acuticornis''
* '' Dichotomius adrastus''
* '' Dichotomius affinis''
* '' Dichotomius agenor''
* '' Dichotomius agesilaus ...
''
** ''
Heliocopris
''Heliocopris'' (large dung beetles) is a genus of Scarabaeidae or scarab beetles in the superfamily Scarabaeoidea
Scarabaeoidea is a superfamily of beetles, the only subgroup of the infraorder Scarabaeiformia. Around 35,000 species are placed ...
''
** ''
Metacatharsius
''Metacatharsius'' is a genus of dung beetles in the tribe Coprini (subfamily Scarabaeinae) of the scarab family. It comprises more than 60 species from Africa; one is also found in Arabia, and Pakistan
Pakistan ( ur, ), officially t ...
Copris elphenor
''Copris'' is a genus of dung beetles in the tribe Coprini (subfamily Scarabaeinae) of the scarab family. It comprises more than 250 tunnelling species and has an almost worldwide distribution.
Species
Gallery
Copris arizonensis - Dung Beet ...
'' female
File:Copris elphenor Klug, 1855 male (4012106288).jpg, ''
Copris elphenor
''Copris'' is a genus of dung beetles in the tribe Coprini (subfamily Scarabaeinae) of the scarab family. It comprises more than 250 tunnelling species and has an almost worldwide distribution.
Species
Gallery
Copris arizonensis - Dung Beet ...
'' male
*
Deltochilini
Deltochilini (or Canthonini) is a tribe of scarab beetles, in the dung beetle subfamily ( Scarabaeinae). Members of this group vary widely in size (2–33 mm long) and shape, but were thought to be derived from an ancient ball-rolling line ...
(= Canthonini) - about 120 genera including:
** '' Anachalcos'' Hope, 1837
** '' Canthon'' Hoffmannsegg, 1817
** ''
Circellium
The flightless dung beetle (''Circellium bacchus'') is a species of dung beetle endemic to a few areas of South Africa, including the Addo Elephant National Park, Amakhala Game Reserve and the Buffalo Valley Game Farm. It is the only species in ...
Dicranocara
''Dicranocara'' is a genus of Scarabaeidae or scarab beetles in the superfamily Scarabaeoidea. ''Dicranocara'' is endemic to the Richtersveld National Park. Three species are known, ''D. deschodti'' Frolov and Scholtz, ''D. tatasensis'' Deschodt ...
'' Frolov and Scholtz, 2003
** ''
Epirinus
''Epirinus'' is a genus of dung beetles in the tribe Deltochilini (subfamily Scarabaeinae) of the scarab family. It comprises 29 species from southern Africa
Africa is the world's second-largest and second-most populous continent, aft ...
'' Reiche, 1841
** ''
Parachorius
''Parachorius''Harold E von (1873) Diagnosen neuer coprophagen. ''Coleopterologische Hefte'' 11: 102-105. is a genus of Asian Scarabaeidae or scarab beetles.
Species
''BioLib''Versicorpus'' Deschodt Davis and Scholtz, 2011
Plum dung beetle (Anachalcos convexus).jpg, ''
Anachalcos convexus
''Anachalcos convexus'' is a species of scarab beetle in the genus ''Anachalcos
''Anachalcos'' is a genus of Scarabaeidae or scarab beetles in the superfamily Scarabaeoidea
Scarabaeoidea is a superfamily of beetles, the only subgroup of ...
Onthophagus
Gazella scarab ('' Onthophagus gazella'') males; note variation in horn size
''Onthophagus'' is a genus of dung beetles in the Onthophagini tribe of the wider scarab beetle family, Scarabaeidae. It is the most species-rich and widespread genus ...
''
** ''
Proagoderus
''Proagoderus'' is a genus of Scarabaeidae or scarab beetles in the subfamily Scarabaeinae. It was considered a subgenus of Onthophagus
Gazella scarab ('' Onthophagus gazella'') males; note variation in horn size
''Onthophagus'' is a genus o ...
Onthophagus binodis
Gazella scarab ('' Onthophagus gazella'') males; note variation in horn size
''Onthophagus'' is a genus of dung beetles in the Onthophagini tribe of the wider scarab beetle family, Scarabaeidae. It is the most species-rich and widespread genus i ...
Onthophagus gazella
''Onthophagus gazella'' (common names: gazella scarab, brown dung beetle) is a species of scarab beetle. It belongs to the subgenus ''Digitonthophagus
''Digitonthophagus'' is a genus of Scarabaeidae or scarab beetles in the superfamily Scaraba ...
''
File:Onthophagus (= Proagoderus) imperator Castelnau, 1840 male (4155161435).jpg, ''
Proagoderus imperator
''Proagoderus'' is a genus of Scarabaeidae or scarab beetles in the subfamily Scarabaeinae. It was considered a subgenus of Onthophagus
Gazella scarab ('' Onthophagus gazella'') males; note variation in horn size
''Onthophagus'' is a genus o ...
''
Predominantly Old World (New World presence likely represents rather recent dispersal)
* Oniticellini (incl. Eurysternini) - 16 genera including:
** ''
Euoniticellus
''Euoniticellus'' is a genus of dung beetles in the subfamily Scarabaeinae of the scarab beetle
The family Scarabaeidae, as currently defined, consists of over 30,000 species of beetles worldwide; they are often called scarabs or scarab beetl ...
'' Janssens, 1953
** ''
Oniticellus
''Oniticellus'' is a genus of dung beetles in the subfamily Scarabaeinae of the scarab beetle
The family Scarabaeidae, as currently defined, consists of over 30,000 species of beetles worldwide; they are often called scarabs or scarab beetle ...
'' Serville, 1825
** ''
Eurysternus
''Eurysternus'' is a genus of Scarabaeinae or dung beetles in the family Scarabaeidae. It is normally placed in the Oniticellini, although some authors consider it the single genus in the tribe Eurysternini (e.g.). It is restricted to the Neotrop ...
''
*
Sisyphini
Sisyphini is a tribe of scarab beetles, in the dung beetle subfamily ( Scarabaeinae), but it may now be combined with the Scarabaeini.B ...
- three genera (sometimes placed in the
Scarabaeini
The ScarabaeiniLatreille PA (1802) ''Histoire naturelle, générale et particulière des Crustacés et des Insectes. Tome 3.'' F. Dufart, Paris. are a tribe of old-world dung beetle genera, erected by Pierre André Latreille.
Genera
''BioLib' ...
):
** ''
Nesosisyphus
''Nesosisyphus'' is a genus of Scarabaeidae or scarab beetles in the superfamily Scarabaeoidea
Scarabaeoidea is a superfamily of beetles, the only subgroup of the infraorder Scarabaeiformia. Around 35,000 species are placed in this superfamily ...
''
** ''
Neosisyphus
''Neosisyphus'' is a genus of Scarabaeidae or scarab beetles in the superfamily Scarabaeoidea
Scarabaeoidea is a superfamily of beetles, the only subgroup of the infraorder Scarabaeiformia. Around 35,000 species are placed in this superfamily ...
''
** ''
Sisyphus
In Greek mythology, Sisyphus or Sisyphos (; Ancient Greek: Σίσυφος ''Sísyphos'') was the founder and king of Ephyra (now known as Corinth). Hades punished him for cheating death twice by forcing him to roll an immense boulder up a hill ...
Garreta
''Garreta'' is a genus of dung beetles (subfamily Scarabaeinae) in the scarab beetle family ( Scarabaeidae). There are more than 20 described species; most are African and some are from Asia. They are generally found in fairly moist habitats (fo ...
Paragymnopleurus
''Paragymnopleurus''Shipp JW (1897) On the genus Gymnopleurus Illiger, with a list of species and descriptions of two new genera. ''The Entomologist'' 30:62-66; 131-135; 166-168. is a genus of Asian dung beetles in the tribe Scarabaeini
The Sc ...
''
*
Scarabaeini
The ScarabaeiniLatreille PA (1802) ''Histoire naturelle, générale et particulière des Crustacés et des Insectes. Tome 3.'' F. Dufart, Paris. are a tribe of old-world dung beetle genera, erected by Pierre André Latreille.
Genera
''BioLib' ...
- selected genera:
** '' Scarabaeus'' ('' Kheper'' is a subgenus)
*
Onitini
The OnitiniHope FW (1837) ''The coleopterist’s manual, containing the Lamellicorn insects of Linneus and Fabricius.'' Henry G. Bohn, London, pp. i–xiii + 15–121 + pls. 1–3, are a tribe of old-world dung beetle genera, erected by Freder ...
- selected genera:
** ''
Bubas
''Bubas'' is a genus of Scarabaeidae in the superfamily Scarabaeoidea."Genus: ''Bubas''" Glob ...
Onitis
''Onitis'' is a genus of Scarabaeidae or scarab beetles in the superfamily Scarabaeoidea and typical of the tribe Onitini
The OnitiniHope FW (1837) ''The coleopterist’s manual, containing the Lamellicorn insects of Linneus and Fabricius.'' ...
Ennearabdus
''Ennearabdus'' is a genus of Scarabaeidae or scarab beetles in the superfamily Scarabaeoidea.
References
Scarabaeidae
{{Scarabaeidae-stub ...
''
** ''
Eucranium
''Eucranium'' is a genus of Scarabaeidae or scarab beetles in the superfamily Scarabaeoidea.
References
Scarabaeidae
{{Scarabaeidae-stub ...
''
** ''
Glyphoderus
''Glyphoderus'' is a genus of Scarabaeidae or scarab beetles in the superfamily Scarabaeoidea
Scarabaeoidea is a superfamily of beetles, the only subgroup of the infraorder Scarabaeiformia. Around 35,000 species are placed in this superfamily ...
Oxysternon
''Oxysternon'' is a genus of Scarabaeidae or scarab beetles in the superfamily Scarabaeoidea. It can be distinguished from all other phanaeines and scarabaeine dung beetles by a long, spiniform extension of the anterior angle of the metasternum. ...