Founding of Temporary Parasitic and Slave-maker Ants

Founding of Temporary Parasitic and Slave-maker Ants

What are Temporary Parasite Ants?

Social Parasitism within ants are queens of the parasitic species which require workers from a host species in order to found colonies. For the sake of brevity, this will cover only Formica and Lasius parasites.

Social Parasites

“There are three main types of social parasites that form mixed species ant nests: temporary social parasites, permanent inquilines, and slave-makers” (Deslippe).

Temporary social parasites:

“Temporary social parasites depend on a host species only during the establishment of new colonies. Usually the parasitism is initiated by young queens following their insemination in a mating flight. The queens try to penetrate host colonies, replace the original queens, and gain acceptance by the workers. The parasitic queens then lay eggs that develop, with the care of the host colony workers, into a worker force of their own offspring. Eventually the host workers die leaving only the parasitic queens and their offspring. As a result, a mature colony contains only members of the parasitic species” (Deslippe).

Permanent inquilines

“Whereas temporary social parasites typically kill the host queens, queens of permanent inquilines are usually tolerant of the host queens. With a few exceptions, inquilines do not produce worker offspring, but instead invest most of their energy into producing eggs that eventually develop into sexual forms. Despite the burden, the host queens continue to produce worker offspring and so the mixed species colony is permanent. The host workers simultaneously rear the brood of both the parasitic and non-parasitic queens” (Deslippe). I’m not sure if there are any parasitic Formica that do this, but I will include it here anyways.

Slave Raiders

“The antics of the slave-makers have made them a favorite among myrmecologists. Besides initiating their nests much like the temporary social parasites, the slave-makers also raid other ant colonies to steal the brood. The pilfered larvae and pupae that are not consumed eventually eclose into worker slaves that are chemically imprinted and completely integrated into the society of their enslavers. The slaves tend brood, gather food, feed their enslavers, care for the queen, and defend the nest against threats. If the colony moves to a new location, the slaves carry their enslavers to their new nest. Sometimes, the slaves even participate with the slave-making workers in slave raids against other ant colonies of their own or closely related species” (Deslippe).


The Lasius section of this guide contains information from BatSpiderFish's


Subgenus Acanthomyops:
North America:
Lasius arizonicus,  Lasius bureni, Lasius californicus, Lasius colei, Lasius colei, Lasius claviger, Lasius creightoni, Lasius occidentalis, Lasius pogonogynus, Lasius pubescens, Lasius subglaber, 

Acanthomyops Lasius, also known as citronella ants, are subterranean root-aphid farmers from North America. Of the parasitic Lasius, these are the largest group, with Lasius interjectus having workers over 6mm long. With the exception of Lasius interjectus, which flies in May-July, Acanthomyops fly in late fall. I myself have seen Lasius claviger out on a day with frost. Queens will often infiltrate colonies in large groups.

Acanthomyops queens have a tendency of dying wihtout cause, but one theory is that the hybrids produced by interspecies matings in the subgenus create non-viable queens.

Subgenus Chthonolasius:
North America (Excluding Synonyms):
Lasius aphidicolus, Lasius atopis, Lasius humilis, Lasius minutus, Lasius nevadensis, Lasius speculiventris, Lasius subumbratus, Lasius vestitus

Eurasia  (Excluding Synonyms):
Lasius balcanicus, Lasius bicornis, Lasius umbratus, Lasius citrinus, Lasius distinguendus, Lasius jensi, Lasius meridionalis, Lasius mixtus,, Lasius nitidigaster, Lasius rabaudi, Lasius sabularum, Lasius viechmeyeri

Cthonolasius are a mostly-subterranean species of Lasius which is able to both forage above ground and  farm root aphids. Many species build carton nests from a fungus they grow. Both queens and workers of Cthonolasius are duller than queens and workers of Acanthomyops. They can be distinguished with their browner colouration and the lack of citronella odor.

Cthonolasius are the easiest group of parasites to keep in captivity, and seem to be much more accepting of workers and have a much smaller rate of random deaths than other Lasius subgenera. Cthonolasius are best kept using Cthonolasius hosts and Lasius-niger group hosts. Otherwise, care is identical to other Lasius species.

Subgenus Dendrolasius:
Eurasia (Excluding Synonyms):
Lasius buccatus, Lasius capitatus, Lasius fuliginosus, Lasius spathepus
Dendrolasius can be identified with a convex depression at the top of the head, as well as long, light legs and antennae (similar to Formica exsecta-group). Colonies create nests using fungus cartons, and secret citronella, similarly to Acanthomyops. Dendrolasius are also very shiny and black. Even though Dendrolasius are famed for their parasitism on Cthonolasius, they can be founded just as easily with niger-group and flavus-group Lasius. 

Subgenus Austrolasius:
Eurasia(Excluding Synonyms): 

Lasius carniolicus, Lasius reginae  

Austrolasius is a very little-studied group  of social parasites. Austrolasius are parasitic upon Lasius alienus/americanus, and have not yet been kept in captivity as far as I'm aware. 

Colony Founding Techniques

Callow Method

Obtain Lasius callows, which are freshly eclosed Lasius workers, which can be identified by their slow-moving speed and pale colouration. I am personally partial to collecting large numbers of Lasius pupae and workers, and collecting the callows as they hatch. Slowly introduce callow workers to the queen, and feed them periodically with sugars. Make sure not to place substrate in the tube, lest the queen seal herself off and the workers become aggressive.

Natural Colony Method

Obtain a queenless colony. This can be achieved by collecting large numbers of Lasius wokers and brood. Place a queen inside a test tube in an outworld, and then the queenless colony in another. Usually, the queen will go into the test tube with the queenless colony. Sometimes workers will show signs of aggression. Make sure to monitor the colony at this time and remove the queen if ay aggression occurs. If all goes well, the queen will have become assimilated into the colony and all that's left is to wait.

Natural Colony w/ pre-killed workers

This method is the same as the Natural colony method, but the queen is introduced to a crushed worker beforehand so that the queen adapts the host colony's scent.

Chilling Method

Put both queens and host workers into a fridge until they slow down. Place the queen into the test tube containing the workers. Remove after the grooming and/or feeding is observed.

Tips and Tricks

Queens sometimes take days, weeks, or even months to lay eggs. Usually, the first egg will signal for sure that the colony will survive. The number of eggs produced depends on the number of hosts. 

It is important to balance the number of hosts and the aggression of hosts. More host workers will be more aggressive, and often rip up biological workers. At the same time, more host workers mean that more eggs will be laid by the queen.


The Formica section of this guide was written by AntsBC. However, I have made some minor edits in terms of formatting and content regarding the range of acceptable hosts.

There are three groups of temporary socially parasitic Formica: the F. rufa group, the F. microgyna group, and the F. exsecta group.  Also, there is one group of slave raiding Formica: the F. sanguinea group. This guide also applies for Polyergus, or amazon ants.  I will cover the temporary social parasites first and then the slave raiders after.


(Formica s. str) Formica rufa Group:


Formica obscuripes, By Sean McCann

Keys Including this Group:

North American Species include (synonyms have been left out):

Formica aterrima, Formica calviceps, Formica ciliata, Formica coloradensis, Formica comata, Formica criniventris, Formica dakotensis, Formica ferocula, Formica fossaceps, Formica integra, Formica integroides, Formica laeviceps, Formica mucescens, Formica obscuripes, Formica obscuriventris, Formica oreas, Formica planipilis, Formica prociliata, Formica propinqua, Formica ravida, Formica reflexa, and Formica subnitens.

Eurasian Species Include (synonyms have been left out):

Formica adelungi, Formica approximans, Formica aquilonia, Formica dusmeti, Formica kupyanskayaeFormica lugubris, Formica opaca, Formica paralugubris, Formica polyctena, Formica pratensis, Formica rufa, Formica truncorum, Formica sinensis, Formica frontalis, Formica yessensis, Formica uralensis, and Formica wongi.

Hosts: Serviformica, Neoformica, or more specifically a Formica fusca group species.

Diet: These ants are very fond of honey, sugar water, and other sweet carbohydrates.  They will also openly accept most insects and arachnids.  Furthermore, member species of the F. rufa group particularly enjoy Lepidoptera larvae, and many species will hunt for them in trees. 

Distinguishing Characteristics/Biology:

The Formica rufa group is best known for the massive mounds which included species create in the wild.  For the most part, these mounds are made out of sticks, leaf litter, grass blades, and other organic material.  Most species live in the forest, but some live in grasslands as well.  Workers are usually polymorphic.  Most of the included species have red and black coloration.  Queen and worker size varies greatly amongst the included species.  Nuptial flights generally occur in July - August, although some species, (such as Formica obscuripes) will fly as early as late April.  Colony founding usually includes dealate queens seeking out host colonies, killing the host queen, and then using the remaining host worker force to raise her brood.  The host worker force will slowly die out, leaving only the parasitic queen and her workers.  Some species will accept dealate queens back into the nest.  Colonies can be polygynous (having multiple queens) and polydomous (having multiple nests per colony).

(Formica s. str) Formica microgyna Group


Formica densiventris Queen, By Gary Alpert

Keys Including this Group:

North American Species Include (synonyms have been left out):

Formica adamsi, Formica densiventris, Formica difficilis, Formica dirksi, Formica impexa, Formica indianensis, Formica knighti, Formica microgyna, Formica morsei, Formica nepticula, Formica nevadensis, Formica postoculata, Formica querquetulana, Formica scitula, Formica spatulata, and Formica talbotae.

Hosts: Serviformica, or more specifically a member species of the F. fusca or F. neogagates group.

Distinguishing Characteristics/Biology (Note: There are very little resources available on the F. microgyna group, I tried my best to gather the information I could):

The Formica microgyna group is believed to have evolved from the F. rufa group.  Key differences between the two include size, (workers and queens, (especially queens) of the F. microgyna group are generally quite smaller than those of the F. rufa group) and habitat; (the F. rufa group usually prefers forests while the F. microgyna group prefers grasslands and prairies).  F. microgyna group queens are ordinarily very slender looking too.  Member species of the F. microgyna reproduce and create new colonies like the F. rufa group; (colony founding usually includes dealate queens seeking out host colonies, killing the host queen, and then using the remaining host worker force to raise her own brood).

(Coptoformica) Formica exsecta Group


Formica ulkei Queen and worker with F. podzolica and F. aserva Host Workers, By Crystal S



Formica exsecta Queen Alate and workers, By Hayley Wiswell


Keys Including this Group:

North American Species Include (synonyms have been left out):

Formica exsectoides, Formica opaciventris, and Formica ulkei.

Eurasian Species Include (synonyms have been left out):

Formica bruni, Formica exsecta, Formica manchu, Formica mesasiatica, Formica fukaii, Formica fennica, Formica pressilabris, Formica foreli, Formica forsslundi, Formica pisarskii, and Formica suecica.

Hosts: Serviformica or more specifically a Formica fusca group species.

Distinguishing Characteristics/Biology:

All member species of the F. exsecta group possess a distinct concave posterior cephalic margin.


Member species of this group are mound builders like the other parasitic Formica spp.  They prefer to nest in forests and will create multi nest supercolonies like those of the F. rufa group.  They create new colonies like the rest of the parasitic Formica groups, and they do generally let queens back into their nests.

Slave Raiders:

(Raptiformica) Formica sanguinea Group

Formica cf. subintegra Queen with Formica fusca Host Workers, By Antshaman


North American Species Include: 

Formica aserva, Formica creightoni, Formica curiosa, Formica gynocrates, Formica sanguinea subnuda, Formica subintegra, Formica obtusopilosa, Formica pergandei, Formica puberula, Formica rubicunda, and Formica wheeleri.

Eurasian Species Include:

Formica sanguinea.

Hosts: Preferably Serviformica or a Formica fusca group species, but they are known to enslave Lasius spp., Myrmicinae spp., and even other parasitic Formica spp.

Distinguishing Characteristics of this Group/Biology:

The Formica sanguinea group is the only slave raiding group of Formica.  Member species of the group are spread throughout the U.S. and Canada, and Formica sanguinea has large populations throughout Europe.  Slave raiding workers and queens can be identified from other Formica spp. by the dense pubescence on their gasters, their large, sickle looking jaw frame, and the presence of a cypeal notch near their mouths.  Slave raiders are usually quite large in comparison to other Formica species.

Formica sanguinea group slave raiders generally sit inside their nest all day, every day; except for when they go on slave raids.  They do not forage themselves.  The slaves do everything from raising brood, foraging for food, taking care of the nest, etc.  All the slave raiders do is slave raid, hence the name. 

A raid begins by a scout finding a host colony.  The scout then comes back to her nest to gather a raiding party.  Then, a raiding party goes out and breaks into the nest, stealing callows and brood, of which will serve as future slaves.

Colony foundation for slave raiding Formica is much the same as parasitic colonies: dealate queens seek out host colonies, kill the host queen, and then using the remaining host worker force to raise her brood.  Although, slave raiding Formica queens are known to single handily raid host colonies; taking their brood and stashing it inside a burrow.  Later, they will open the pupae and let the newborn slaves take care of their brood.  Other parasitic Formica queens are known to do this, but not as frequently as slave raiding Formica queens.


Colony Founding Techniques

Raising Parasitic Formica:

Parasitic Formica queens generally fly in the middle of the summer, with the bulk of them flying from July- August, so keep an eye out for them in those months.  Dealate queens can be found searching for host colonies to infiltrate after their nuptial flights.

The key difference between raising parasitic Lasius vs. Formica is for the most part, parasitic Formica spp. can open pupae, while parasitic Lasius cannot.  So, instead of using methods of host worker introduction right away, you can offer your queen some pupae first.  Personally, I like to use a four step method for raising parasitic Formica.  I have used this method in the past with success so I would recommend using it.  This method incorporates introducing pupae first and then workers later if the queen failed to open the pupae.  

So, without further ado, let’s get into it:


Brood Method:

1. Assuming you have a queen, you should first provide her a source of liquid sugar, as they have few food stores. Feeding will ensure she has energy throughout the founding process.

2. Obtain some host pupae. In the wild, fusca group is most commonly used (Black Formica). However, I find that most species of Formica are viable. IDing your queen may help a lot on that front, as you can be more exact on your queen's host species. Once you find a colony of your queen’s host species, I would suggest collecting around 30 pupae and 10 workers, (host workers may come in handy later).  Remember, you can always go back for more pupae later. This may be done with a shovel in the early morning.

3.Grab a few (4-8) pupae from your host colonies’ setup and offer them to your queen. Make sure to leave some pupae in your host worker’s setup.  They may come in handy later.

4a. Most parasitic Formica can open pupae. If your queen manages to open the pupae before they start to die, you won’t be needing your host workers anymore; as all you need is more pupae!  I would offer the pupae into your parasitic queen’s setup gradually, as if you offer all 10-50 at once, your colony will be overwhelmed and some pupae will die.

4b. If your queen is unable to open pupae and the pupae die, your queen will need the host workers.  The reason I suggested you collect the host workers before you necessarily need them is because the longer those workers are separated from their real queen and colony, the more their scent fades.  Ants rely on scent to determine whether or not other ants are apart of their colony, so if your host workers have been separated for 2+ weeks from their colony they have a higher chance of accepting and joining forces with the parasitic queen.

When introducing host workers to parasitic queens, I like to use the callow method.  The reason I told you to leave some pupae in your host worker’s setup earlier is so you could use them as host workers now.  As the pupae start to get older, the host workers will open the cocoons and new workers will be born.  Freshly born ants are called callows. Callows haven’t been fully alive long enough to truly inherit the now fading host colonies' scent, making them an even better option for host workers.  If you don't know what callows look like, try to find a worker in the setup that is slow moving and quite pale.

She is probably a callow.  Before you introduce the callows to your queen, make sure you follow these short steps:

Callow Method:

After removing the dead/decaying pupae out of your parasitic queen’s setup, feed your queen some honey or your preferred carbohydrate.  This way, she will have enough energy for when the host workers are introduced and she won’t be hungry, (which also means there will be a lower chance of her killing the host workers for food).

Finally, collect around 1-4 callows and introduce them to your queen.  Monitoring their interactions at this stage is very crucial. Callow workers are weak, and are unlikely to hurt the queen. However, the queen may not be so friendly. As a general rule, ants in a group are more likely to attack something then if they are alone. Introducing a small amount of workers also makes it easier to intervene if necessary.  If all goes as planned, the queen will accept the host workers and you will have yourself a parasitic colony!  If she has accepted the host workers, you can gradually add in more and more pupae so your host workforce will grow. 



Formica pratensis Queen with Host Workers, By Lusatica

Presuming that one of these methods worked and your parasitic queen has meshed with the host workers, now all you have to do is wait until your queen lays eggs and eventually gets her first generation of offspring.  Keep in mind, parasitic Formica queens generally start laying eggs after their first hibernation.  If your queen doesn’t lay eggs right away, it doesn’t necessarily mean she’s infertile; she could very well just be waiting for hibernation. Treat your parasitic colony like a normal colony in the time before your parasitic queen’s offspring arrives, (and after they do too).  Feed them like you would a normal colony, (but maybe with a little more care).  Once you get a substantial parasitic workforce, you could even consider moving the colony into a naturalistic setup.  If you offer the materials that the species you are keeping makes their mounds out of in the wild, you could possibly see them create a big mound like they would in the wild!

Also, keep in mind parasitic Formica spp. have an important relationship with their habitat and survival rates.  (Credit to AntsAreUs for that information).  Because of this, it is rather important to supply your parasites with naturalistic components, such as dirt, sand, twigs, etc.  I like to sterilize all the items from nature I put in my setups just to rid them of any harmful bacteria that they may be carrying.  This can be achieved by baking or freezing.  

For those of you who sadly did not succeed in getting your parasitic queen past the founding stages, I send my condolences.  Sometimes, despite everything you do and try, things still don’t go as planned.  If your queen has died, there isn’t really anything you can do at this point besides go and try to find another.  If she is still alive but her host workers are dead, you could try to repeat the process.  On the second go, I would try to get a different host species if you weren’t 100% sure on the exact ID of your queen.  Possibly, you just got the wrong host species. 

Tips and Tricks

General Tips for parasitic Formica: 

- Make sure you feed your parasite sugars and proteins throughout all of the above stages.  Parasitic queens are not fully claustral.  Due to the low infiltration success rates in the wild, parasitic colonies focus on quantity vs. quality when producing alates.  Instead of making sure every alate is well fed, they focus on producing as many alates as possible.  Your parasite has a chance of dying if you do not feed her.

- Sometimes, even though host workers will not attack the parasitic queen, they will still not be united with the queen.  This generally occurs when introducing mature, adult workers only; especially when introducing workers from separate colonies.  Indicators of the workers lacking unification with the queen include the host workers constantly trying to escape the setup, host workers avoiding/ignoring the parasite, host workers refusing to clean the parasite and host workers denying/not initiating trophallaxis with the parasite.  Although these symptoms may be portrayed shortly after introducing the hosts to the parasite, if they ensue for long than a week, I would start to get worried.  Introducing callows and pupae lower the chance of this.  Callows have not yet fully obtained their mother colonies' scent and pupae will take on the scent of whichever colony they are born to.  If you have witnessed detrimental symptoms prolong for a week or more, introduce the parasite to new hosts or a new host species.  Also, try to find pupae and produce callows, (assuming you haven't already).  As I mentioned before, this condition generally only happens when you introduce adult workers only.  Positive evidence that the hosts have indeed integrated with the parasite include the hosts initiating and holding trophallaxis with the parasite, cleaning the parasite and residing with the parasite.  

- Parasitic species lay more eggs when more host workers are present, which is something to keep in mind when setting up your parasite with hosts.  This is a result of two things:

1) More hosts = more ants that can take care of brood

2) Parasitic queens like to at least match or double the number of host workers there are in comparison to the number of parasitic, biological workers there are.  

Raising Formica rufa-group: These ants need nests with good ventilation, in order to help degrade the effects of any formic acid, (methanoic acid) that the colony may spray.  They also have a very distinct relationship with their environment and their success, so I find it's a good idea to introduce some naturalistic elements to their nest (Eg. Dirt/twigs for them to decorate their test tube with).  These ants also benefit greatly from having a constant supply of carbohydrates, such as honey or sugar water.


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