subfamily
In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus
Genus ( plural genera ) is a taxonomic rank used in the biological classifica ...
family
Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...
(Scarabaeidae). Other common names – some for particular groups of rhinoceros beetles – include
Hercules beetle
The Hercules beetle (''Dynastes hercules'') is a species of rhinoceros beetle native to the rainforests of Central America, South America, and the Lesser Antilles. It is the longest extant species of beetle in the world, and is also one of t ...
species
In biology, a species is the basic unit of 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 the appropriat ...
and 225
genera
Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomenclat ...
of rhinoceros beetles are known.
Many rhinoceros beetles are well known for their unique shapes and large sizes. Some famous species are, for example, the
Atlas beetle
The Atlas beetle (''Chalcosoma atlas'') is a very large species of beetle in the family Scarabaeidae, found in Southeast Asia. Males have three prominent horns. The species is named for Atlas, the giant of Greek mythology who supported the ski ...
(''Chalcosoma atlas''),
common rhinoceros beetle
''Xylotrupes ulysses'', common names "Elephant beetle", "Coconut palm beetle", "common rhinoceros beetle" or simply "rhinoceros beetle" is a species of rhinoceros beetle native to New Guinea. Male horns in several groups of this genus represent ...
(''Xylotrupes ulysses''),
elephant beetle
The elephant beetle (''Megasoma elephas'') is a member of the family Scarabaeidae and the subfamily Dynastinae. They are Neotropical rhinoceros beetles.
Appearance
Elephant beetles are black in color and covered with a coat of fine microscopi ...
(''Megasoma elephas''),
European rhinoceros beetle
The European rhinoceros beetle (''Oryctes nasicornis'') is a large flying beetle belonging to the subfamily Dynastinae.
Subspecies
* ''Oryctes nasicornis afghanistanicus'' Endrödi, 1938
* ''Oryctes nasicornis chersonensis'' Minck, 1915
* ''Or ...
(''Oryctes nasicornis''),
Hercules beetle
The Hercules beetle (''Dynastes hercules'') is a species of rhinoceros beetle native to the rainforests of Central America, South America, and the Lesser Antilles. It is the longest extant species of beetle in the world, and is also one of t ...
ox beetle
''Strategus aloeus'', the ox beetle, is a species of rhinoceros beetle. The "major" males of this species have three large horns on their thoraces, resembling the Triceratops
''Triceratops'' ( ; ) is a genus of herbivorous chasmosaurine ...
(''Strategus aloeus'') and the
Eastern Hercules beetle
''Dynastes tityus'', the eastern Hercules beetle, is a species of rhinoceros beetle native to the Eastern United States. The adult's elytra are green, gray or tan, with black markings, and the whole animal, including the male's horns, may reach ...
(''Dynastes tityus'').
Description and ecology
The Dynastinae are among the largest of beetles, reaching more than in length, but are completely harmless to humans because they cannot bite or sting. Some species have been anecdotally claimed to lift up to 850 times their own weight. An extinct
Eocene
The Eocene ( ) Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', ...
Oryctini
Oryctini is a tribe of beetles in the Dynastinae (family Scarabaeidae).Bouchard, P., Y. Bousquet, A. Davies, M. Alonso-Zarazaga, J. Lawrence, C. Lyal, A. Newton, et al. (2011). "Family-group names in Coleoptera (Insecta)". ''ZooKeys, vol. 88'', ...
grew up to . Common names of the Dynastinae refer to the characteristic horns borne only by the males of most species in the group. Each has a horn on the head and another horn pointing forward from the center of the thorax. The horns are used in fighting other males during mating season, and for digging. The size of the horn is a good indicator of nutrition and physical health.
The body of an adult rhinoceros beetle is covered by a thick
exoskeleton
An exoskeleton (from Greek ''éxō'' "outer" and ''skeletós'' "skeleton") is an external skeleton that supports and protects an animal's body, in contrast to an internal skeleton ( endoskeleton) in for example, a human. In usage, some of the ...
. A pair of thick wings lie atop another set of membranous wings underneath, allowing the rhinoceros beetle to fly, although not very efficiently, owing to its large size. Their best protection from predators is their size and stature. Additionally, since they are
nocturnal
Nocturnality is an animal behavior characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal", versus diurnal meaning the opposite.
Nocturnal creatures generally have highly developed sens ...
, they avoid many of their predators during the day. When the sun is out, they hide under logs or in vegetation to
camouflage
Camouflage is the use of any combination of materials, coloration, or illumination for concealment, either by making animals or objects hard to see, or by disguising them as something else. Examples include the leopard's spotted coat, the b ...
themselves from the few predators big enough to want to eat them. If rhinoceros beetles are disturbed, some can release very loud, hissing squeaks. The hissing squeaks are created by rubbing their abdomens against the ends of their wing covers. Rhinoceros beetles are relatively resilient; a healthy adult male can live up to 2–3 years. The females rarely live long after they mate.
These beetles' larval stages can be several years long. The larvae feed on rotten wood and the adults feed on
nectar
Nectar is a sugar-rich liquid produced by plants in glands called nectaries or nectarines, either within the flowers with which it attracts pollinating animals, or by extrafloral nectaries, which provide a nutrient source to animal mutualist ...
,
plant sap
Sap is a fluid transported in xylem cells (vessel elements or tracheids) or phloem sieve tube elements of a plant. These cells transport water and nutrients throughout the plant.
Sap is distinct from latex, resin, or cell sap; it is a se ...
, and
fruit
In botany, a fruit is the seed-bearing structure in flowering plants that is formed from the ovary after flowering.
Fruits are the means by which flowering plants (also known as angiosperms) disseminate their seeds. Edible fruits in partic ...
. First, the larvae hatch from eggs and later develop into pupae before they reach adult status (see picture at left). The females lay 50 eggs on average. Contrary to what their size may imply, adult rhinoceros beetles do not eat large amounts, unlike their larvae, which eat a significant amount of rotting wood.
Mating
Male Japanese rhinoceros beetles (''Allomyrina dichotoma'') fight to dominate sap sites. Males use their horns to pry rival males off the area, which also may give them the chance to mate with a female. In this and other species that defend mating sites, larger males with larger horns mate more frequently, as they win more contests. Small males often avoid larger males and exhibit alternative strategies to gain access to females.
Interactions with humans
Use by humans
Rhinoceros beetles have become popular pets in parts of
Asia
Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an area ...
, due to being relatively clean, easy to maintain, and safe to handle. Also in Asia, male beetles are used for gambling fights. Since males naturally have the tendency to fight each other for the attention of females, they are the ones used for battle. To get the two male beetles to lock in combat, a female beetle is used, or a small noisemaker duplicating the female's
mating call
A mating call is the auditory signal used by animals to attract mates. It can occur in males or females, but literature is abundantly favored toward researching mating calls in females. In addition, mating calls are often the subject of mate choic ...
.
Entomologist
Entomology () is the scientific study of insects, a branch of zoology. In the past the term "insect" was less specific, and historically the definition of entomology would also include the study of animals in other arthropod groups, such as arach ...
protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respo ...
(40%) than
chicken
The chicken (''Gallus gallus domesticus'') is a domesticated junglefowl species, with attributes of wild species such as the grey and the Ceylon junglefowl that are originally from Southeastern Asia. Rooster or cock is a term for an adult m ...
(20%) and
beef
Beef is the culinary name for meat from cattle (''Bos taurus'').
In prehistoric times, humankind hunted aurochs and later domesticated them. Since that time, numerous breeds of cattle have been bred specifically for the quality or quantity ...
National Science Foundation
The National Science Foundation (NSF) is an independent agency of the United States government that supports fundamental research and education in all the non-medical fields of science and engineering. Its medical counterpart is the National I ...
-funded research, examined the function and aerodynamics of '' Allomyrina dichotoma'' with the help of researchers in
Drexel University
Drexel University is a private research university with its main campus in Philadelphia, Pennsylvania. Drexel's undergraduate school was founded in 1891 by Anthony J. Drexel, a financier and philanthropist. Founded as Drexel Institute of Art, S ...
's Mechanical Engineering Department and in collaboration with
Konkuk University
Konkuk University () is a South Korean private university founded in 1946. The university was founded based on three virtues: sincerity, fidelity, and righteousness.
Konkuk University gives comprehensive education in agricultural and life scien ...
in South Korea. Rhinoceros beetles could play a big part in the next generation of aircraft design.
As pests
Some species can become major pests, e.g., in tree plantations. Usually though, beetle
population densities
Population density (in agriculture: standing stock or plant density) is a measurement of population per unit land area. It is mostly applied to humans, but sometimes to other living organisms too. It is a key geographical term.Matt RosenberPopu ...
are not as high as in some other pest insects, and they typically prefer food trees which are already sick or dying from some other cause. Some species' larvae, however, will attack healthy trees or even
root vegetable
Root vegetables are underground plant parts eaten by humans as food. Although botany distinguishes true roots (such as taproots and tuberous roots) from non-roots (such as bulbs, corms, rhizomes, and tubers, although some contain both hypocotyl a ...
s, and when they occur in large numbers, can cause economically significant damage. The fungus ''
Metarhizium anisopliae
''Metarhizium robertsii'' formerly known as ''M. anisopliae'', and even earlier as ''Entomophthora anisopliae'' (basionym) is a fungus that grows naturally in soils throughout the world and causes disease in various insects by acting as a paras ...
'' is a proven biocontrol agent for beetle infestation in crops.
Ancognatha
''Ancognatha'' is a genus of rhinoceros beetles in the family Scarabaeidae. There are more than 20 described species in ''Ancognatha''.
Species
These 22 species belong to the genus ''Ancognatha'':
* ''Ancognatha atacazo'' (Kirsch, 1885)
* ''Anc ...
Atlas beetle
The Atlas beetle (''Chalcosoma atlas'') is a very large species of beetle in the family Scarabaeidae, found in Southeast Asia. Males have three prominent horns. The species is named for Atlas, the giant of Greek mythology who supported the ski ...
** ''
Chalcosoma moellenkampi
The Moellenkampi beetle (''Chalcosoma moellenkampi''), is one of four large species of rhinoceros beetles from Southeast Asia belonging to the genus ''Chalcosoma''. The Moellenkampi beetles belong to the beetle family Scarabaeidae along with oth ...
Dynastes
''Dynastes'' is a genus of large beetles belonging to the family Scarabaeidae. They occur in the Nearctic realm and in the Neotropical realm, from the United States to Brazil;Dynastes hercules
The Hercules beetle (''Dynastes hercules'') is a species of rhinoceros beetle native to the rainforests of Central America, South America, and the Lesser Antilles. It is the longest extant species of beetle in the world, and is also one of the ...
'' – Hercules beetle
**''
Dynastes neptunus
''Dynastes'' is a genus of large beetles belonging to the family Scarabaeidae. They occur in the Nearctic realm and in the Neotropical realm, from the United States to Brazil;Eupatorus'' Burmeister, 1847
**''
Eupatorus gracilicornis
''Eupatorus gracilicornis'', the five-horned rhinoceros beetle ( th, ด้วงกว่างซางเหนือ (DâwŋGwā̀ŋŞāŋĦeNǖx)) is a beetle that has four large horns on the prothorax and one extra-long cephalic horn. Rhin ...
Eupatorus birmanicus
''Eupatorus'' is a genus of rhinoceros beetles (subfamily Dynastinae of the family Scarabaeidae).
Species
The genus contains the following species, typically found in Indo-China:
* '' Eupatorus birmanicus'' Arrow, 1908
* '' Eupatorus endoi'' Na ...
'' – Rabbit beetle
* ''
Megasoma
''Megasoma'' is a genus of rhinoceros beetles. Commonly known as the elephant beetles, ''Megasoma'' species are found from the southern half of North America to most of South America.
Appearance
''Megasoma'' are generally large in size (as indic ...
'' Kirby, 1825
**''
Megasoma mars
''Megasoma mars'', also known as the mars beetle or mars rhino beetle, is the largest species in the ''Megasoma'' genus. It is distributed primarily in the west-central Amazon basin of Brazil, ranging down into Colombia, Paraguay, and Uruguay, Ur ...
Megasoma actaeon
Actaeon beetle (''Megasoma actaeon'') is a rhinoceros beetle of the family Scarabaeidae.
Etymology
The species name ''actaeon'' derives from the name Actaeon of a famous Theban hero, son of the priestly herdsman Aristaeus and Autonoe in Boeot ...
Oryctini
Oryctini is a tribe of beetles in the Dynastinae (family Scarabaeidae).Bouchard, P., Y. Bousquet, A. Davies, M. Alonso-Zarazaga, J. Lawrence, C. Lyal, A. Newton, et al. (2011). "Family-group names in Coleoptera (Insecta)". ''ZooKeys, vol. 88'', ...
Auth: Mulsant, 1842. Selected genera:
* ''
Enema
An enema, also known as a clyster, is an injection of fluid into the lower bowel by way of the rectum.Cullingworth, ''A Manual of Nursing, Medical and Surgical'':155 The word enema can also refer to the liquid injected, as well as to a device ...
Oryctes
''Oryctes'' is the most economically important genus of rhinoceros beetles in the subfamily Dynastinae (family: Scarabaeidae), since it includes a notorious insect pest of palms.
Species
Currently, 42 species are in the genus, including:
* ' ...
'' Hellwig, 1798
** ''Oryctes nasicornis'' –
European rhinoceros beetle
The European rhinoceros beetle (''Oryctes nasicornis'') is a large flying beetle belonging to the subfamily Dynastinae.
Subspecies
* ''Oryctes nasicornis afghanistanicus'' Endrödi, 1938
* ''Oryctes nasicornis chersonensis'' Minck, 1915
* ''Or ...
Strategus
''Strategos'', plural ''strategoi'', Latinized ''strategus'', ( el, στρατηγός, pl. στρατηγοί; Doric Greek: στραταγός, ''stratagos''; meaning "army leader") is used in Greek to mean military general. In the Hellenis ...
Trichogomphus
''Trichogomphus'' Burmeister HCC (1847) ''Handbuch der Entomologie. Coleoptera Lamellicornia, Xylophila et Pectinicornia. Enslin. Berlin'' 5:1-584. is a genus of Asian beetles in the family Scarabaeidae and tribe Oryctini
Oryctini is a tribe ...
*
*Dechambre (R.-P.) & Lachaume (G.) '' The Beetles of the World'', volume 27, The genus ''Oryctes'' (Dynastidae),
Hillside Books, Canterbury Hillside Books, Canterbury was a publisher specialising in books on entomology and small equipment associated with this science.
Origin
It was established in 1989, directed by Lydie Leforestier.
Initially it was in Canterbury, England but then ...