Parasitism is the most common lifestyle on Earth [1,2], and parasites can target hosts across the full range of biological complexity, from single cells to individuals, and entire societies. Hosts in turn can fend off parasites via their genetic constitution and/or physiological responses (innate and induced immunity [3– 5]), and by adjusting their behaviour to avoid and/or treat infection (behavioural immunity [6]). Over evolutionary time, parasites and their hosts are locked in an arms race, where parasites continually evolve mechanisms to exploit hosts more effectively, while hosts continually evolve better defences [7]. Nests of social insects (ants, bees, wasps, and termites) can be especially attractive to parasites, because they usually contain high densities of genetically similar individuals, and rich resource stores [8]. Within social insects, some species have evolved to parasitize other social insects [9–12]. Social parasites are especially numerous in ants, where they fall roughly into three categories: permanent inquilines, slave-makers, and temporary social parasites [9,13]. Permanent inquilines coexist with the host species, whereas slave-making
ants raid other colonies to capture and enslave their brood [13,14]. In temporary social parasite species, parasite queens invade host colonies, kill the host queen(s), initiate egg-laying, and take advantage of the brood care behaviour of host workers. If successful, this can lead to the loss of the entire future reproductive output of the host colony [9].
References
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parasites. Q. Rev. Biol. 75, 277 –293.
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3. Mu¨ller U, Vogel P, Alber G, Schaub GA. 2008 The
innate immune system of mammals and insects.
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A Schmidt, H Herwald), pp. 21–44. Basel,
Switzerland: Karger.
4. Rolff J, Reynolds SE. 2009 Insect infection and
immunity: evolution, ecology, and mechanisms.
Oxford, NY: Oxford University Press.
5. Riera RM, Pe´rez-Martı´nez D, Castillo Ferrer C. 2016
Innate immunity in vertebrates: an overview.
Immunology 148, 125–139. (doi:10.1111/imm.
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6. de Roode JC, Lefe`vre T. 2012 Behavioral immunity
in insects. Insects 3, 789–820. (doi:10.3390/
insects3030789)
7. Davies NB, Bourke AF, Brooke M. 1989 Cuckoos
and parasitic ants: interspecific brood parasitism
as an evolutionary arms race. Trends Ecol. Evol.
4, 274–278. (doi:10.1016/0169-5347
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8. Schmid-Hempel P. 1995 Parasites and social insects.
Apidologie 26, 255–271. (doi:10.1051/apido:19950307)
9. Buschinger A. 2009 Social parasitism among ants: a
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https://www.antwiki.org/wiki/images/1/1b/Pulliainen%2C_U.%2C_Helantera%2C_H._et_al._2019._The_possible_role_of_ant_larvae_in_the_defence_against_social_parasites_%2810.1098%40rspb.2018.2867%29.pdf
Parasitic castration is a strategy where parasites disrupt or block their host's reproductive abilities to their own benefit, often by diverting energy from reproduction to parasite or host growth. This strategy is seen in various parasitic species, including some insects, trematodes, and crustaceans. Parasites may achieve this by directly damaging the host's reproductive organs, secreting chemicals that interfere with reproduction, or altering host behaviour to promote parasite survival.
Here's a more detailed explanation:
How it works:
Direct Damage: Some parasites physically damage or consume the host's reproductive organs, like how the parasitic barnacle Sacculina can cause the testes of its crab host to degenerate.
• Chemical Interference: Other parasites release chemicals that disrupt the host's reproductive process, such as the trematode Zoogonus lasius, which chemically castrates snails.
• Behavioral Manipulation: Some parasites can manipulate the host's behaviour to enhance parasite transmission or survival. For example, the parasite Xenos vesparum can alter the behavior of its paper wasp host, causing it to abandon the colony and potentially die, benefiting the parasite.
• Resource Diversion: Parasites may divert energy that would normally be used for reproduction to parasite growth or host growth, potentially leading to gigantism in the host.
Examples:
• Strepsipteran insects: Xenos vesparum is a well-studied example of a parasitic castrator that affects paper wasps.
• Trematodes: Various trematode species, like those found in molluscs, can castrate their hosts, diverting energy that would normally go into reproduction into host growth and parasite development.
• Barnacles: Barnacles like Sacculina can cause male crabs to develop female secondary sex characteristics and lose their reproductive ability.
Consequences:
• Host: Castrated hosts lose their ability to reproduce, which can impact the host population dynamics.
• Parasite: Parasitic castration allows parasites to exploit the host's resources more effectively, potentially increasing their reproductive success and survival.
Evolutionary Considerations:
• Trade-off: Parasitic castration represents a trade-off between host consumption and parasite longevity.
• Coevolution: Host populations may evolve counter-adaptations to parasitic castration, such as increased early reproduction before being castrated
Social parasitism is the coexistence of two or more ant species in one nest or colony. It involves a parasitic species which is dependent on one or several host species. The relationship can be obligatory or facultative, permanent or temporary. These relationships can take many forms and have been classified in various ways.
Holldobler & Wilson (1990), following a suggestion of Wasmann (1891), distinguished between "compound nests" and "mixed colonies".
• Compound nests (xenobiosis) involve two species of ants living together in the same nest but keeping their broods separate. One species lives in the walls or chambers of the nests of the other and moves freely among its hosts, obtaining food from them by one means or another, usually by soliciting regurgitation. The details of specific relationships vary with the species involved, and can broadly be classified into a series of essentially continuous types.
◦ Plesiobiosis. In this most rudimentary association, different ant species nest very close to each other, but engage in little or no direct communication.
◦ Cleptobiosis. Some species of small ants build nests near those of larger species and either feed on refuse in the host kitchen middens or rob the host workers when they return home carrying food.
◦ Lestobiosis. Certain small species, most belonging to Solenopsis and related genera, stay in the walls of large nests built by other ants or termites and enter the nest chambers of their hosts to steal food and prey on the inhabitants.
◦ Parabiosis. In this peculiar form of symbiosis, two or more species use the same nest and sometimes even the same odour trails, but they keep their brood separate.
• Mixed colonies comprise temporary parasites, slave-makers (dulosis) and inquilines, where the host workers care for the parasite brood, at least temporarily.
As an alternative, Buschinger (2009), in his review of social parasitism, proposed the following classification:
• Xenobiosis (guest ants, sometimes called cleptobiosis or kleptobiosis) - The biology of Formicoxenus nitidulus provides natural history information about one representative guest ant.
• Temporary parasitism (occurring together only during colony foundation) - The biology of Lasius umbratus provides natural history information about one representative temporarily parasitic ant.
• Permanent parasitism with slavery (dulosis) - The biology of Temnothorax muellerianus and Polyergus rufescens provide representative accounts of dulosis. Note that slave-making species range from being largely self-sufficient and easily able to survive without the support of slaves (facultative dulosis, as in Formica sanguinea), to having a very limited behavioral repertory and apparently completely helpless without their slaves (referred to as degenerate slavemakers) (Holldobler & Wilson, 1990).
"Obligatory slavemakers" are completely and permanently dependent on regular replenishment of their slave stock by raiding host species colonies. The term "degenerate slavemaker" has been coined for species that belong to a monophylum of obligatory slavemaking species but have secondarily abandoned the slavemaker worker caste, or reduced its number, hence can‘t conduct slave raids. Examples are Temnothorax kraussei (reduced slavemaker workers to a few, or zero), Temnothorax corsicus and Temnothorax adlerzi (both workerless; all three belong to former genus Myrmoxenus), and Temnothorax brunneus (workerless, former genus Chalepoxenus). The distinction is necessary since the queens of the degenerate slavemakers have retained the colony foundating behavior of their actively dulotic relatives, i.e. kill the host coloy queen by throttling her to death (former Myrmoxenus) or stinging (former Chalepoxenus). This is different from workerless inquilines whose queens live in queenright host species colonies, and who most probably derive directly from an independent species (example Leptothorax kutteri and Leptothorax pacis with Leptothorax acervorum as host species).
• Permanent parasitism without slavery (inquilinism) - The biology of Tetramorium inquilinum (as Teleutomyrmex schneideri) provides natural history information about one representative inquiline ant.
Parasite Evolution
Understanding how ants evolved to be parasites of other ants is an important, long-standing question.Hölldoble rand Wilson (1990) stated the following "Social parasitism in ants is complicated . . . the source of the complexity is first the large number of ant species that have entered into some form of parasitic relationship with each other. Second, at least two and possibly three major evolutionary routes lead to the ultimate stage of permanent, workerless parasitism. Finally, no two species are exactly alike in the details of their parasitic adaptation."
Chemical Deception Among Social Parasites
Guillem et al. (2014) examined cuticular hydrocarbon (CHC) profiles among the parasites Camponotus universitatis, Harpagoxenus sublaevis and Strongylognathus testaceus and their hosts. They found that the parasitic species had CHC profiles that were indistinguishable from that of their hosts, even when the parasite is using more than one host species. The level of chemical mimicry even extended to the more subtle between-colony differences in profiles. In all cases the profiles of un-parasitized colonies were similar to those that were parasitized indicating that it is the parasites that have adjusted their profile to match that of their host and not vice versa. This explains why these social parasites are fully integrated members of each colony and are treated as nest-mates.
They also noted that in some species, for example Harpagoxenus sublaevis (Winter and Buschinger, 1986), raiding workers are frequently killed or driven off when trying to raid or invade new host colonies, since they are carrying their own host colony odour, which is likely to be different from that of the one they are raiding. This is why parasites continue to use a wide range of other chemical and morphological adaptations associated with their parasitic lifestyle. These include a thickened cuticle and production of ((( appeasement or propaganda compounds ))) (e.g. Allies et al., 1986; Lloyd et al., 1986; Ollett et al., 1987; D'Ettorre et al., 2000). These tactics allow the parasite time to make the necessary adjustments to its profile. Acquiring a host profile may be possible in just a few hours (R. Kather, pers. comm., cited in Guillem et al. (2014)).
https://www.antwiki.org/wiki/Social_Parasitism
Abstract. Ant inquilines are obligate social parasites, usually lacking a sterile worker
caste, which are dependent on their hosts for survival and reproduction. Social parasites are rare among the fungus-gardening ants (Myrmicinae: tribe Attini) and only four species are known until now, all being inquilines from the Higher Attini. We describe Mycocepurus castrator sp.n., the first inquiline social parasite to be discovered in the Lower Attini. Our study of the parasite’s behaviour and life history supports the conclusion drawn from external morphology: Mycocepurus castrator is an evolutionarily derived inquiline parasite of Mycocepurus goeldii. Inquilines are of great interest to evolutionary biology because it is debated if they originated via sympatric or allopatric speciation. We discuss the life history evolution, behaviour and morphology of socially parasitic, fungus-growing ants.
Introduction
Societies of all social organisms are defined by reproductive division of labour, co-operative brood care and overlapping generations (Batra, 1966; Mitchener, 1969; Wilson, 1971; H¨olldobler & Wilson, 1990). Among the social insects, ants are unique in that all extant species are eusocial, except for a few inquiline social parasites, in which eusociality has been lost secondarily, due to the marked reduction (or more often complete loss) of the worker caste. Inquiline social parasites are
highly adapted to exploit their host colonies and depend completely on the host workers for food provisioning, brood care, and other colony maintenance tasks (Kutter, 1969; Wilson, 1971; Buschinger, 1986, 2009; H¨olldobler & Wilson, 1990; Bourke & Franks, 1991).
Ant social parasites may be categorized according to their host interactions (Wasmann, 1891; H¨olldobler & Wilson,1990). (i) In temporary social parasites, the parasite queen must be adopted by a host colony and depends on the host colony to raise the first generation of her own worker offspring. When sufficient workers of the parasitic species are produced, the colony becomes independent of the host. (ii) Dulotic or slave-making parasites steal worker brood from host colonies and the emerging host workers provide social tasks (i.e. brood care, foraging, nest hygiene) that ensure the parasite colony’s survival. In addition, dulotic queens found colonies parasitically in a manner similar to temporary social parasites. (iii) Inquiline parasites depend on the host species for their entire life cycle. The inquiline foundress invades a host colony and uses the host workers to raise her sexual brood. Interestingly, the parasite queen generally does not produce a sterile worker force. Thus, her reproductive output depends entirely on the host species. In host-queen tolerant inquilines, host and parasite queens coexist, but the host queen’s fitness is compromised because the
parasite inhibits the production of sexual offspring, whereas the production of host workers is continued. In contrast, the inquiline queen maximizes her fitness by producing exclusively sexual offspring (Kutter, 1969; Wilson, 1971; Buschinger, 1986; H¨olldobler & Wilson, 1990). Because host workers continue to be produced, the parasitized colony may survive indefinitely. In host-queen intolerant inquilines (a minority of inquiline species) the host queen is eliminated somehow and reproduction of the parasite ceases when the host workers die off. Thus, parasitized colonies have a short life span.
Etymology. During collections of M. castrator, the host colonies were not observed to produce any alate queens and males, although sympatrically nesting M. goeldii colonies released alates. Therefore, we assume that the inquiline inhibits the host queens’ production of sexual offspring, allowing only for the production of the sterile worker caste. This is essentially ‘social castration’, hence the specific name ‘castrator’.
https://antwiki.org/wiki/images/a/ad/Rabeling_&_Bacci_2010.pdf
Funny how universal phenomena apply from the smallest to the largest scales. Especially when you consider social castes and the existence of the priesthood and enforcer caste. With this situation wouldn’t the host lose its priesthood to castration and celibacy leading to a normie and social parasite world?