View source for Biology:Dynastinae

{{Short description|Subfamily of beetles}}
{{Automatic taxobox
| fossil_range = {{fossil range|Eocene|Recent}}
| image = Dynastinae.jpg
| image_alt = Rhinoceros Beetle
| taxon = Dynastinae
| authority = MacLeay, 1819
| subdivision_ranks = Tribes
| subdivision = See text<ref>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'', 1-972.</ref>
}}
[[File:Oryctes nasicornis male 2012 G1.jpg|thumb|300px| European rhinoceros beetle]]

'''Dynastinae''' or '''rhinoceros beetles''' are a subfamily of the [[Biology:Scarabaeidae|scarab beetle]] family (Scarabaeidae). Other common names &ndash; some for particular groups of rhinoceros beetles &ndash; include '''[[Biology:Hercules beetle|Hercules beetle]]s''', '''unicorn beetles''' or '''horn beetles'''. Over 1500 [[Biology:Species|species]] and 225 genera of rhinoceros beetles are known.<ref name="handbook_coleoptera_vol2">{{cite book | editor-last=Beutel | editor-first=Rolf G. | editor-last2=Leschen | editor-first2=Richard A.B. | title=Coleoptera, Beetles, Volume 1, Morphology and Systematics (Archostemata, Adephaga, Myxophaga, Polyphaga partim) | publisher=De Gruyter | date=2016-03-21 | isbn=978-3-11-037392-9 | doi=10.1515/9783110373929 }}</ref>

Many rhinoceros beetles are well known for their unique shapes and large sizes. Some famous species are, for example, the [[Biology:Atlas beetle|Atlas beetle]] (''Chalcosoma atlas''), common rhinoceros beetle (''Xylotrupes ulysses''), [[Biology:Elephant beetle|elephant beetle]] (''Megasoma elephas''), [[Biology:European rhinoceros beetle|European rhinoceros beetle]] (''Oryctes nasicornis''), [[Biology:Hercules beetle|Hercules beetle]] (''Dynastes hercules''), [[Biology:Japanese rhinoceros beetle|Japanese rhinoceros beetle]] or ''kabutomushi'' (''Allomyrina dichotoma''), ox beetle (''Strategus aloeus'') and the Eastern Hercules beetle (''Dynastes tityus'').

==Description and ecology==
[[File:Three stages rhinoceros beetle.jpg|thumb|left| European rhinoceros beetle &ndash; three stages from larva to adult:<br/>Larva (back), pupa (center), imago (front)]]
The Dynastinae are among the largest of beetles, reaching more than {{convert|15|cm|in|0|abbr=on}} 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.<ref>{{cite journal |last1=Kram |first1=Rodger |title=Inexpensive load carrying by rhinoceros beetles |journal=Journal of Experimental Biology |date=1 March 1996 |volume=199 |issue=3 |pages=609–612 |doi=10.1242/jeb.199.3.609 |pmid=9318326 |url=https://journals.biologists.com/jeb/article/199/3/609/7375/Inexpensive-Load-Carrying-by-Rhinoceros-Beetles }}</ref> An extinct [[Earth:Eocene|Eocene]] ''[[Biology:Oryctoantiquus|Oryctoantiquus borealis]]'' was the largest fossil scarabeid, with a length of {{convert|5|cm}}.<ref name=Brett2009>Brett Ratcliffe, Dena M. Smith, Diane Marie Erwin. "[https://www.researchgate.net/publication/232682009_Oryctoantiquus_borealis_New_Genus_and_Species_from_the_Eocene_of_Oregon_USA_the_World's_Oldest_Fossil_Dynastine_and_Largest_Fossil_Scarabaeid_Coleoptera_Scarabaeidae_Dynastinae Oryctoantiquus borealis, New Genus and Species from the Eocene of Oregon, U.S.A., the World's Oldest Fossil Dynastine and Largest Fossil Scarabaeid (Coleoptera: Scarabaeidae: Dynastinae)]". 2009. The Coleopterists Bulletin 59(Mar 2005):127-135 DOI:10.1649/0010-065X(2005)059[0127:OBNGAS]2.0.CO;2</ref> Some modern [[Biology:Oryctini|Oryctini]] grew up to {{convert|7|cm}}.<ref name=Brett2009/> 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.<ref>{{cite web |url=https://www.newscientist.com/blogs/nstv/2012/07/why-horn-size-matters-when-picking-a-mate.html?DCMP=OTC-rss&nsref=online-news |title=Why horn size matters when picking a mate|work=New Scientist}}</ref>

The body of an adult rhinoceros beetle is covered by a thick [[Biology:Exoskeleton|exoskeleton]]. 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 [[Earth:Predation|predators]] is their size and stature. Additionally, since they are nocturnal, they avoid many of their predators during the day. When the sun is out, they hide under logs or in vegetation to [[Biology:Camouflage|camouflage]] 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.{{citation needed|reason=likely inaccurate|date=August 2016}}

These beetles' [[Biology:Larva|larval stages]] can be several years long. The larvae feed on rotten wood and the adults feed on [[Biology:Nectar|nectar]], plant sap, and [[Biology:Fruit|fruit]]. First, the larvae hatch from eggs and later develop into pupae before they reach [[Biology:Adult|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.{{Citation needed|date=October 2019}}

==Mating==

Male [[Biology:Japanese rhinoceros beetle|Japanese rhinoceros beetle]]s (''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.<ref>{{cite journal |last1=Buchalski |first1=Benjamin |last2=Gutierrez |first2=Eric |last3=Emlen |first3=Douglas |last4=Lavine |first4=Laura |last5=Swanson |first5=Brook |title=Variation in an Extreme Weapon: Horn Performance Differences across Rhinoceros Beetle (Trypoxylus dichotomus) Populations |journal=Insects |date=15 October 2019 |volume=10 |issue=10 |pages=346 |doi=10.3390/insects10100346 |pmid=31618906 |pmc=6835817 |doi-access=free }}</ref><ref>{{cite journal |last1=Goczał |first1=Jakub |last2=Rossa |first2=Robert |last3=Tofilski |first3=Adam |title=Intersexual and intrasexual patterns of horn size and shape variation in the European rhinoceros beetle: quantifying the shape of weapons |journal=Biological Journal of the Linnean Society |date=17 April 2019 |volume=127 |issue=1 |pages=34–43 |doi=10.1093/biolinnean/blz026 }}</ref>

== Interactions with humans ==

=== Use by humans ===
Rhinoceros beetles have become popular pets in parts of [[Earth:Asia|Asia]],<ref>"WHO? KNEW" (May 6, 2005) ''Current Science'' Vol.90 No.16</ref> due to being relatively clean, easy to maintain, and safe to handle. Also in Asia, male beetles are used for gambling fights.<ref>[http://www.articlesextra.com/beetle-fight-xylotrupes-thailand.htm Rhinoceros beetle gambling in Thailand]</ref> 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 [[Biology:Mating call|mating call]].

[[Biology:Entomology|Entomologist]] Séverin Tchibozo suggests the larvae contain much more [[Biology:Protein|protein]] (40%) than [[Biology:Chicken|chicken]] (20%) and beef (approximately 18%), and they could become a [[Biology:Entomophagy|protein source for a large human population]].<ref>''Global Steak - Demain nos enfants mangeront des criquets'' (2010 French documentary)</ref>

Dr. MinJun Kim, leading a team of engineers in [[Organization:National Science Foundation|National Science Foundation]]-funded research, examined the function and aerodynamics of ''Allomyrina dichotoma'' with the help of researchers in [[Organization:Drexel University|Drexel University]]'s Mechanical Engineering Department and in collaboration with Konkuk University in South Korea. Rhinoceros beetles could play a big part in the next generation of aircraft design.<ref>{{cite news|url=https://www.sciencedaily.com/releases/2012/04/120410163531.htm|title=Engineers Unlock Secrets of Beetle Flight|date=April 11, 2012|newspaper=ScienceDaily|format=news story|quote=''ScienceDaily (Apr. 10, 2012)'' — Rhinoceros beetles could play a big part....}}</ref>

=== As pests ===
Some species can become major pests, e.g., in tree plantations. Usually though, beetle population densities 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 [[Biology:Root vegetable|root vegetable]]s, and when they occur in large numbers, can cause economically significant damage. The fungus ''[[Biology:Metarhizium majus|Metarhizium majus]]'' is a proven biocontrol agent for beetle infestation in crops.

==Tribes with selected genera and species==
<!-- list species here when there is no genus article but a species article already -->

===Agaocephalini===
[[File:Antodon goryi NMNS.jpg|thumb|''Antodon goryi'']]
Auth: Burmeister, 1847. all genera:
# ''Aegopsis'' <small>Burmeister, 1847</small>
# ''[[Biology:Agaocephala|Agaocephala]]'' <small>Lepeletier & Audinet-Serville, 1828</small>
# ''[[Biology:Antodon|Antodon]]'' <small>Brême, 1845</small>
# ''Brachysiderus'' <small>Waterhouse, 1881</small>
# ''Colacus'' <small>Ohaus, 1910</small>
# ''Democrates'' (beetle) <small>Burmeister, 1847</small>
# ''Gnathogolofa'' <small>Arrow, 1914</small>
# ''Horridocalia'' <small>Endrödi, 1974</small>
# ''Lycomedes'' (beetle) <small>Breme, 1844</small>
# ''Mitracephala'' <small>Thomson, 1859</small>
# ''[[Biology:Spodistes|Spodistes]]'' <small>Burmeister, 1847</small>

===[[Biology:Cyclocephalini|Cyclocephalini]]===
[[File:Cyclocephal_borealis_Adult.jpg|thumb|right|upright|''[[Biology:Cyclocephala borealis|Cyclocephala borealis]]'' (Cyclocephalini)]]
Auth: Laporte, 1840. Selected genera:
* ''[[Biology:Ancognatha|Ancognatha]]'' <small>Erichson, 1847</small>
* ''[[Biology:Cyclocephala|Cyclocephala]]'' <small>Dejean, 1821</small> (masked chafers)
* ''[[Biology:Dyscinetus|Dyscinetus]]'' <small>Harold, 1869</small> (rice beetles)

===[[Biology:Dynastini|Dynastini]]===
[[File:Eupatorus gracilicornis Vol.jpg|thumb|right|upright|''Eupatorus gracilicornis'' (Dynastini)]]
Auth: MacLeay, 1819. Selected genera:
* ''[[Biology:Allomyrina|Allomyrina]]'' <small>Arrow, 1911</small> (including ''Trypoxylus'')
** ''Allomyrina dichotoma'' &ndash; [[Biology:Japanese rhinoceros beetle|Japanese rhinoceros beetle]]
* ''[[Biology:Chalcosoma|Chalcosoma]]'' <small>Hope, 1837</small>
**''Chalcosoma atlas'' &ndash; [[Biology:Atlas beetle|Atlas beetle]]
** ''Chalcosoma moellenkampi'' – Moellenkampi beetle
** ''[[Biology:Chalcosoma caucasus|Chalcosoma caucasus]]'' – Caucasus beetle
* ''[[Biology:Dynastes|Dynastes]]'' <small>MacLeay, 1819</small>
**''Dynastes hercules'' – Hercules beetle
**''[[Biology:Dynastes neptunus|Dynastes neptunus]]'' – Neptune beetle
* ''[[Biology:Eupatorus|Eupatorus]]'' <small>Burmeister, 1847</small>
**''[[Biology:Eupatorus gracilicornis|Eupatorus gracilicornis]]'' – Five-horned rhinoceros beetle
**''[[Biology:Eupatorus siamensis|Eupatorus siamensis]]'' – Siamese beetle
**''[[Biology:Eupatorus birmanicus|Eupatorus birmanicus]]'' – Rabbit beetle
* ''[[Biology:Megasoma|Megasoma]]'' <small>Kirby, 1825</small>
**''[[Biology:Megasoma mars|Megasoma mars]]'' - Mars beetle
**''Megasoma elephas'' - Elephant beetle
**''Megasoma actaeon'' - Actaeon beetle
* ''[[Biology:Xylotrupes|Xylotrupes]]'' <small>Hope, 1837</small>
**''[[Biology:Xylotrupes gideon|Xylotrupes gideon]]'' – Siamese rhinoceros beetle
** ''[[Biology:Xylotrupes ulysses|Xylotrupes ulysses]]''

===[[Biology:Hexodontini|Hexodontini]]===
Auth. Lacordaire, 1856; genera:
# ''Hemicyrthus'' <small>Reiche, 1860</small>
# ''Hexodon'' <small>Olivier, 1789</small>
# ''Hyboschema'' <small>Péringuey, 1901</small>

===[[Biology:Oryctini|Oryctini]]===
[[File:Trichogomphus mongol (Arrow,1908) 60 mm Rhinoceros Beetle male (7941206664).jpg|thumb|right|upright|''Trichogomphus mongol'' (Oryctini)]]
Auth: Mulsant, 1842. Selected genera:
* ''Enema'' <small>Hope, 1837</small>
* ''Megaceras'' <small>Hope, 1837</small><!-- "Megacerna" is lapsus -->
** ''[[Biology:Megaceras briansaltini|Megaceras briansaltini]]''
* ''[[Biology:Oryctes|Oryctes]]'' <small>Hellwig, 1798</small>
** ''Oryctes nasicornis'' &ndash; [[Biology:European rhinoceros beetle|European rhinoceros beetle]]
** ''Oryctes rhinoceros'' &ndash; [[Biology:Asiatic rhinoceros beetle|Asiatic rhinoceros beetle]]
* ''[[Biology:Strategus (beetle)|Strategus]]'' <small>Kirby, 1828</small>
** ''[[Biology:Strategus aloeus|Strategus aloeus]]'' &ndash; ox beetle
* ''[[Biology:Trichogomphus|Trichogomphus]]'' <small>Burmeister, 1847</small>
* ''[[Biology:Xyloryctes|Xyloryctes]]''

===Oryctoderini===
Auth. Endrödi, 1966; all genera:
# ''Chalcasthenes'' <small>Arrow, 1937</small>
# ''Chalcocrates'' <small>Heller, 1903</small>
# ''Coenoryctoderus'' <small>Prell, 1933</small>
# ''Hatamus'' <small>Sharp, 1877</small>
# ''Melanhyphus'' <small>Fairmaire, 1881</small>
# ''Neohyphus'' <small>Heller, 1896</small>
# ''Onychionyx'' <small>Arrow, 1914</small>
# ''Oryctoderinus'' <small>Endrödi, 1978</small>
# ''Oryctoderus'' <small>Boisduval, 1835</small>
# ''Paroryctoderus'' <small>Dechambre, 1994</small>

===[[Biology:Pentodontini|Pentodontini]]===
[[File:Pentodon idiota - Навозник (Дупляк) кукурузный.jpg|thumb|right|upright|''Pentodon idiota'' (Pentodontini)]]
Auth: Mulsant, 1842. Selected genera:
* ''Bothynus'' <small>Hope, 1837</small><!-- RevBrasOrnitol14:359. -->
* ''Diloboderus'' <small>Sturm, 1826</small>
** ''Diloboderus abderus''
* ''[[Biology:Pentodon (beetle)|Pentodon]]'' <small>Hope, 1837</small>
* ''[[Biology:Pericoptus|Pericoptus]]'' <small>Burmeister, 1847</small>
* ''Thronistes'' <small>Burmeister, 1847</small>
* ''[[Biology:Tomarus|Tomarus]]'' <small>Erichson, 1847</small>

===[[Biology:Phileurini|Phileurini]]===
[[File:Phileurus valgus P1620883a.jpg|thumb|right|upright|''[[Biology:Phileurus valgus|Phileurus valgus]]'' (Phileurini)]]
Auth: Burmeister, 1847; selected genera:
* ''Cryptodus'' <small>MacLeay, 1819</small>
* ''[[Biology:Phileurus|Phileurus]]'' <small>Latreille, 1807</small>

==Notes==
{{Reflist|3}}

==Further reading==
*{{Cite book|title=The Dynastinae of the World|last=Endrödi|first=S.|publisher=Dr. W. Junk Publishers|year=1985|isbn=978-9061931386|series=Series Entomologica|volume=28|}}
*Dechambre (R.-P.) & Lachaume (G.) ''The Beetles of the World'', volume 27, The genus ''Oryctes'' (Dynastidae), Hillside Books, Canterbury [https://web.archive.org/web/20100806171758/http://www.insects.demon.co.uk/cm/cm-27-english.html]

==External links==
* [http://www.naturalworlds.org/scarabaeidae/index.htm Family SCARABAEIDAE]
* [https://www.biolib.cz/en/taxonsubtaxa/id8133/ Subfamily Dynastinae]

{{Insects in culture}}
{{Taxonbar|from=Q641142}}

[[Category:Dynastinae| ]]

{{Sourceattribution|Dynastinae}}