Editing Parasitism (section)

=== Variations ===

Among the many variations on parasitic strategies are hyperparasitism,<ref name=Dissanaike1957/> social parasitism,<ref name=Thomas2010/> brood parasitism,<ref name=Payne1997/> kleptoparasitism,<ref name=SlaterRosenblatt2005/> sexual parasitism,<ref name=Pietsch2005/> and adelphoparasitism.<ref name=Rochat2001/>

==== Hyperparasitism ====

{{main|Hyperparasite}}

[[Hyperparasite]]s feed on another parasite, as exemplified by protozoa living in helminth parasites,<ref name=Dissanaike1957>{{cite journal |last1=Dissanaike |first1=A. S. |title=On Protozoa hyperparasitic in Helminth, with some observations on ''Nosema helminthorum'' Moniez, 1887 |journal=Journal of Helminthology |date=1957 |volume=31 |issue=1–2 |pages=47–64 |pmid=13429025 |doi=10.1017/s0022149x00033290|s2cid=35487084 }}</ref> or facultative or obligate parasitoids whose hosts are either conventional parasites or parasitoids.<ref name=PoulinRandhawa2015/><ref name=GullanCranston2010/> Levels of parasitism beyond secondary also occur, especially among facultative parasitoids. In [[oak gall]] systems, there can be up to four levels of parasitism.<ref>{{cite journal |last=Askew |first=R. R. |url=https://www.researchgate.net/publication/238289888 |title=On the Biology of the Inhabitants of Oak Galls of Cynipidae (Hymenoptera) in Britain |journal=Transactions of the Society for British Entomology |date=1961 |volume=14 |pages=237–268}}</ref>

Hyperparasites can control their hosts' populations, and are used for this purpose [[biological pest control|in agriculture]] and to some extent in [[medicine]]. The controlling effects can be seen in the way that the [[Hypovirus#CHV1–Chestnut blight hypovirulence|CHV1 virus]] helps to control the damage that [[chestnut blight]], ''Cryphonectria parasitica'', does to [[American chestnut]] trees, and in the way that [[bacteriophage]]s can limit bacterial infections. It is likely, though little researched, that most pathogenic microparasites have hyperparasites which may prove widely useful in both agriculture and medicine.<ref name="ParrattLaine2016">{{cite journal |last1=Parratt |first1=Steven R. |last2=Laine |first2=Anna-Liisa |title=The role of hyperparasitism in microbial pathogen ecology and evolution |journal=The ISME Journal |volume=10 |issue=8 |date=January 2016|doi=10.1038/ismej.2015.247 |pmid=26784356 |pages=1815–1822|pmc=5029149 |bibcode=2016ISMEJ..10.1815P }}</ref>

==== Social parasitism ====

{{further|Ant mimicry|Cuckoo bee|Emery's rule}}

Social parasites take advantage of interspecific interactions between members of [[eusocial]] animals such as [[ant]]s, [[termite]]s, and [[bumblebee]]s. Examples include the large blue butterfly, ''[[Phengaris arion]]'', its larvae employing [[ant mimicry]]<!--(myrmecomorphy)--> to parasitise certain ants,<ref name="Thomas2010">{{cite journal |last1=Thomas |first1=J. A. |last2=Schönrogge |first2=K. |author3=Bonelli, S. |author4=Barbero, F. |author5=Balletto, E. |title=Corruption of ant acoustical signals by mimetic social parasites: ''Maculinea'' butterflies achieve elevated status in host societies by mimicking the acoustics of queen ants |journal=Commun Integr Biol |volume=3 |issue=2 |pages=169–171 |year=2010 |pmid=20585513 |pmc=2889977 |doi=10.4161/cib.3.2.10603}}</ref> ''[[Bombus bohemicus]]'', a bumblebee which invades the hives of other bees and takes over reproduction while their young are raised by host workers, and ''[[Melipona scutellaris]]'', a eusocial bee whose virgin queens escape killer workers and invade another colony without a queen.<ref>{{Cite journal |first1=Annette |last1=Van Oystaeyen |first2=Denise |last2=Araujo Alves |first3=Ricardo |last3=Caliari Oliveira |first4=Daniela |last4=Lima do Nascimento |first5=Fábio |last5=Santos do Nascimento |first6=Johan |last6=Billen |first7=Tom |last7=Wenseleers |title=Sneaky queens in ''Melipona'' bees selectively detect and infiltrate queenless colonies |journal=Animal Behaviour |date=September 2013 |volume=86 |issue=3 |pages=603–609 |doi=10.1016/j.anbehav.2013.07.001 |citeseerx=10.1.1.309.6081 |s2cid=12921696 }}</ref> An extreme example of interspecific social parasitism is found in the ant ''[[Tetramorium inquilinum]]'', an obligate parasite which lives exclusively on the backs of other ''Tetramorium'' ants.<ref>{{cite web |url=https://www.antkeepers.com/facts/ant-colony/social-parasites/ |title=Social Parasites in the Ant Colony |publisher=Antkeepers |access-date=4 April 2016}}</ref> A mechanism for the evolution of social parasitism was first proposed by Carlo Emery in 1909.<ref>{{Cite journal |last=Emery |first=Carlo |date=1909 |title=Über den Ursprung der dulotischen, parasitischen un myrmekophilen Ameisen |journal=Biologischen Centralblatt |volume=29 |pages=352–362}}</ref> Now known as "[[Emery's rule]]", it states that social parasites tend to be closely related to their hosts, often being in the same genus.<ref name="RD">{{cite web |url=http://www.nature.com/scitable/knowledge/library/social-parasitism-in-ants-13256421 |title=Social Parasitism in Ants |last=Deslippe |first=Richard |publisher=Nature Education Knowledge |year=2010 |access-date=29 October 2010}}</ref><ref name="Emery_1909">{{cite journal |last=Emery |first=C. |url=https://archive.org/details/ants_11715/page/n1 |title=Über den Ursprung der dulotischen, parasitischen und myrmekophilen Ameisen |journal=Biologisches Centralblatt |date=1909 |volume=29 |pages=352–362}}</ref><ref>{{Cite journal |last1=Bourke |first1=Andrew F. G. |last2=Franks |first2=Nigel R. |date=July 1991 |title=Alternative adaptations, sympatric speciation and the evolution of parasitic, inquiline ants |journal=Biological Journal of the Linnean Society |volume=43 |issue=3 |pages=157–178 |doi=10.1111/j.1095-8312.1991.tb00591.x |issn=0024-4066}}</ref>

Intraspecific social parasitism occurs in parasitic nursing, where some individual young take milk from unrelated females. In [[wedge-capped capuchin]]s, higher ranking females sometimes take milk from low ranking females without any reciprocation.<ref name=obrien5>{{cite journal |last=O'Brien |first=Timothy G. |title=Parasitic nursing behavior in the wedge-capped capuchin monkey (''Cebus olivaceus'') |journal=American Journal of Primatology |year=1988 |volume=16 |issue=4 |pages=341–344 |doi =10.1002/ajp.1350160406 |pmid=32079372 |s2cid=86176932 }}</ref>

==== Brood parasitism ====

{{further|Brood parasitism}}

In [[brood parasitism]], the hosts suffer increased parental investment and energy expenditure to feed parasitic young, which are commonly larger than host young. The growth rate of host nestlings is slowed, reducing the host's fitness. Brood parasites include birds in different families such as [[cowbird]]s, [[Viduidae|whydahs]], [[cuckoo]]s, and [[black-headed duck]]s. These do not build nests of their own, but leave their eggs in nests of other [[species]]. In the family ''[[Cuckoo|Cuculidae]]'', over 40% of cuckoo species are obligate brood parasites, while others are either facultative brood parasites or provide parental care.<ref>{{Cite book |last=Payne |first=R. B. |title=The Cuckoos |date=September 15, 2005 |publisher=Oxford University Press |year=2005 |isbn=9780198502135 |edition=1st |location=Oxford |language=en}}</ref> The eggs of some brood parasites [[mimicry|mimic]] those of their hosts, while some cowbird eggs have tough shells, making them hard for the hosts to kill by piercing, both mechanisms implying selection by the hosts against parasitic eggs.<ref name=Payne1997>{{cite book |last=Payne |first=R. B. |date=1997 |chapter=Avian brood parasitism |editor1=Clayton, D. H. |editor2=Moore, J. |title=Host–parasite evolution: General principles and avian models |pages=[https://archive.org/details/hostparasiteevol1997unse/page/338 338–369] |publisher=Oxford University Press |isbn=978-0-19-854892-8 |chapter-url=https://archive.org/details/hostparasiteevol1997unse/page/338 }}</ref><ref>{{cite journal |last1=Rothstein |first1=S. I. |year=1990 |title=A model system for coevolution: avian brood parasitism |journal=Annual Review of Ecology and Systematics |volume=21 |pages=481–508 |doi=10.1146/annurev.ecolsys.21.1.481}}</ref><ref name="DeMarsico2013">{{cite journal |last1=De Marsico |first1=M. C. |last2=Gloag |first2=R. |last3=Ursino |first3=C. A. |last4=Reboreda |first4=J. C. |title=A novel method of rejection of brood parasitic eggs reduces parasitism intensity in a cowbird host |journal=Biology Letters |volume=9 |issue=3 |date=March 2013 |doi=10.1098/rsbl.2013.0076 |pmid=23485877 |pages=20130076|pmc=3645041 }}</ref> The adult female [[European cuckoo]] further mimics a predator, the [[European sparrowhawk]], giving her time to lay her eggs in the host's nest unobserved.<ref name=Welbergen2011>{{cite journal |last1=Welbergen |first1=J. |last2=Davies |first2=N. B. |year=2011 |title=A parasite in wolf's clothing: hawk mimicry reduces mobbing of cuckoos by hosts |journal=[[Behavioral Ecology (journal)|Behavioral Ecology]] |volume=22 |issue=3 |pages=574–579 |doi=10.1093/beheco/arr008|doi-access=free }}</ref> Host species often combat parasitic egg mimicry through egg [[Polymorphism (biology)|polymorphism]], having two or more egg phenotypes within a single population of a species. Multiple phenotypes in host eggs decrease the probability of a parasitic species accurately "matching" their eggs to host eggs.<ref>{{Cite journal |last=Yang, C., X. Si, W. Liang, and A. P. Møller |title=Spatial variation in egg polymorphism among cuckoo hosts across 4 continents |url=https://doi.org/10.1093/cz/zoaa011 |journal=Current Zoology |date=2020 |volume=66 |issue=5 |pages=477–483 |doi=10.1093/cz/zoaa011 |pmid=33293928 |pmc=7705517 |via=Oxford Academic}}</ref>

==== Kleptoparasitism ====

{{further|Kleptoparasitism}}

In [[kleptoparasitism]] (from Greek κλέπτης (''kleptēs''), "thief"), parasites steal food gathered by the host. The parasitism is often on close relatives, whether within the same species or between species in the same genus or family. For instance, the many lineages of [[cuckoo bee]]s lay their eggs in the nest cells of other [[bee]]s in the same family.<ref name="SlaterRosenblatt2005">{{cite book |last1=Slater |first1=Peter J. B. |last2=Rosenblatt |first2=Jay S. |author3=Snowdon, Charles T. |author4=Roper, Timothy J. |author5=Brockmann, H. Jane |author-link5=H. Jane Brockmann |author6=Naguib, Marc |title=Advances in the Study of Behavior |url=https://books.google.com/books?id=WQl2s_xwfagC&pg=PA365 |date=30 January 2005 |publisher=Academic Press |isbn=978-0-08-049015-1 |page=365}}</ref> Kleptoparasitism is uncommon generally but conspicuous in birds; some such as [[skuas]] are specialised in pirating food from other seabirds, relentlessly chasing them down until they disgorge their catch.<ref name="Furness1978">{{cite journal |last=Furness |first=R. W. |title=Kleptoparasitism by great skuas (''Catharacta skua'' Brünn.) and Arctic skuas (''Stercorarius parasiticus'' L.) at a Shetland seabird colony |journal=Animal Behaviour |volume=26 |year=1978 |doi=10.1016/0003-3472(78)90107-0 |pages=1167–1177|s2cid=53155057 }}</ref>

==== Sexual parasitism ====

{{main|Sexual parasitism}}

A unique approach is seen in some species of [[anglerfish]], such as ''[[Ceratias holboelli]]'', where the males are reduced to tiny [[sexual parasite]]s, wholly dependent on females of their own species for survival, permanently attached below the female's body, and unable to fend for themselves. The female nourishes the male and protects him from predators, while the male gives nothing back except the sperm that the female needs to produce the next generation.<ref name=Pietsch2005>{{cite journal |last=Pietsch |first=Theodore W. |title=Dimorphism, parasitism, and sex revisited: modes of reproduction among deep-sea ceratioid anglerfishes (Teleostei: Lophiiformes) |journal=Ichthyological Research |date=25 August 2005 |volume=52 |issue=3 |pages=207–236 |doi=10.1007/s10228-005-0286-2|bibcode=2005IchtR..52..207P |s2cid=24768783 }}</ref>

==== Adelphoparasitism ====

Adelphoparasitism, (from Greek [[wikt:ἀδελφός|ἀδελφός]] (''adelphós''), brother<ref>{{cite book |last1=Maggenti |first1=Armand R. |last2=Maggenti |first2=Mary Ann |last3=Gardner |first3=Scott Lyell |title=Online Dictionary of Invertebrate Zoology |url=http://slovarji.info/dictionaries/en_dictionary_of_invertebras.pdf#page=29 |archive-url=https://web.archive.org/web/20180418031907/http://slovarji.info/dictionaries/en_dictionary_of_invertebras.pdf#page=29 |url-status=dead |archive-date=18 April 2018 |publisher=University of Nebraska |page=22 |date=2005}}</ref>), also known as sibling-parasitism, occurs where the host species is closely related to the parasite, often in the same family or genus.<ref name=Rochat2001>{{cite journal |last1=Rochat |first1=Jacques |last2=Gutierrez |first2=Andrew Paul |title=Weather-mediated regulation of olive scale by two parasitoids |journal=Journal of Animal Ecology |date=May 2001 |volume=70 |issue=3 |pages=476–490 |doi=10.1046/j.1365-2656.2001.00505.x|bibcode=2001JAnEc..70..476R |s2cid=73607283 |doi-access=free }}</ref> In the citrus blackfly parasitoid, ''[[Encarsia perplexa]]'', unmated females may lay [[Ploidy#haploid|haploid]] eggs in the fully developed larvae of their own species, producing male offspring,<ref>{{cite web |title=Featured Creatures. ''Encarsia perplexa'' |url=http://entnemdept.ufl.edu/creatures/beneficial/encarsia_perplexa.htm |publisher=University of Florida |access-date=6 January 2018}}</ref> while the marine worm ''[[Bonellia viridis]]'' has a similar reproductive strategy, although the larvae are planktonic.<ref name="BerecSchembri2005">{{cite journal |last1=Berec |first1=Ludek |last2=Schembri |first2=Patrick J. |last3=Boukal |first3=David S. |url=https://core.ac.uk/download/pdf/46603451.pdf |archive-url=https://web.archive.org/web/20191003131349/https://core.ac.uk/download/pdf/46603451.pdf |archive-date=3 October 2019 |url-status=live |title=Sex determination in ''Bonellia viridis'' (Echiura: Bonelliidae): population dynamics and evolution |journal=Oikos |volume=108 |issue=3 |year=2005 |pages=473–484 |doi=10.1111/j.0030-1299.2005.13350.x|bibcode=2005Oikos.108..473B }}</ref>

==== Illustrations ====

Examples of the major variant strategies are illustrated.

<gallery class="center" mode="nolines" widths="180px">
File:Pteromalid hyperparasitoid.jpg|A hyperparasitoid [[Pteromalidae|pteromalid wasp]] on the cocoons of its host, itself a parasitoid [[braconid wasp]]
File:Maculinea arion Large Blue Upperside SFrance 2009-07-18.jpg|The [[large blue]] butterfly is an [[ant mimicry|ant mimic]] and social parasite.
File:Eastern Phoebe-nest-Brown-headed-Cowbird-egg.jpg|In [[Brood parasite|brood parasitism]], the host raises the young of another species: here a [[cowbird]]'s egg in an [[Eastern phoebe]]'s nest.
File:Great Skua (cropped).jpg|The [[great skua]] is a powerful [[Kleptoparasitism|kleptoparasite]], relentlessly pursuing other seabirds until they disgorge their catches of food.
File:Северная церапия (cropped).jpg|The male of the [[anglerfish]] species ''[[Ceratias holboelli]]'' lives as a tiny [[sexual parasite]] permanently attached below the female's body.
File:Encarsia perplexa.jpg|''[[Encarsia perplexa]]'' (centre), a parasitoid of [[citrus blackfly]] (lower left), is also an adelphoparasite, laying eggs in larvae of its own species
</gallery>