Depending on the species, ants may reproduce either sexually or asexually. Meaning, some ants reproduce through the mating of male and female reproductives while some are able to bypass mating yet still produce offspring.
Both modes of reproduction are generally performed by the queen as they, in most cases, are the only ones capable of reproducing and growing the colony. This is because ants are eusocial animals which exhibit reproductive division of labor. The queen bears all the reproductive burden while worker ants give up their rights to reproduction to raise her offspring.
In this article, we’ll look deeper into how ants reproduce as we discuss how the two modes of reproduction occur in ants.
Sexual Reproduction In Ants
Ants are most commonly known to reproduce sexually. This means that ant reproduction usually involves mating and the coming together of genetic material from two parents to produce offspring.
For example, at certain times of the year, winged reproductive males and virgin queens called alates swarm during what’s called a nuptial flight. There, these ants mate and queen ants store sperm in their spermatheca, an organ in which sperm can be stored and maintained until it’s released for fertilization.
After mating, both males and queens lose their wings. The male ants, having fulfilled their purpose, die soon after; while the queens seal themselves off to safety and use the stored sperm to lay eggs which would eventually hatch into workers and mark the start of a new independent colony.
Once the colony is established, the queen continues to selectively use sperm to lay fertilized or unfertilized eggs depending on the needs of the colony. Fertilized eggs hatch into female workers which under the right circumstances may also turn into queens, while unfertilized eggs develop as males.
A similar process occurs with polygynous ants which colonies have more than one reproductive queen. But instead of swarming, these ants mate within or near their nests and simply return. They then establish new colonies through fragmentation or budding which occurs when a group of ant workers and individual queens break away from their maternal colonies and move to new nests.
When this happens, the newly formed colony may either become hostile or retain firm ties with their maternal colony and allow for the cooperative exchange of brood, workers, and reproductives.
In most ants, workers are sterile and queens are the only ones capable of reproduction. However, in some species like the Harpegnathos saltator, ant workers called gamergates, have spermathecae and can reproduce sexually. Like queens, these gamergates can store and use sperm selectively. Furthermore, they also have haploidoploid sex determination where fertilized eggs hatch into females while unfertilized ones develop into males.
In some species, these gamergates reproduce alongside queens and sometimes even take all reproductive responsibility in queenless colonies. Also, like polygynous ants, they form new colonies through budding.
Asexual Reproduction in Ants
While most ants reproduce sexually, some ants species can also reproduce asexually through parthenogenesis. Through such, both worker ants and queens are able to produce diploid embryos from unfertilized eggs and essentially clone themselves.
For example, Cataglyphis cursor queens and worker ants can produce new queens through asexual parthenogenesis. Interestingly though, they’re one of the rare species which reproduce both asexually and sexually as they can also sexually produce workers.
Other asexually reproducing ant species include the Mycocepurus smithii, Ooceraea biroi, Wasmannia auropunctata, and the Platythyrea punctata.
Can An Ant Colony Have Multiple Queens?
Ants can have a varied number of queens depending on species and ecological factors. Those that reproduce and disperse tend to create independent monogynous colonies with one queen. On the other hand, ants that mate close to their maternal nests tend to come from polygynous colonies which have multiple queens working together. Finally, there are also queenless colonies where workers bear the reproductive responsibility.
How Many Eggs Do Ants Lay Per Day?
Fully healthy queen ants can lay hundreds of eggs daily. For instance, fire ant queens that are properly supplied with food by workers are capable of laying around 800 eggs per day.
Gamergates on the other hand, are often less capable and in some species, can only produce half of what a queen would be able to do daily. This is why gamergate colonies tend to be smaller.
Contrary to common knowledge, ant reproduction isn’t as straightforward and simple. Not only do ants reproduce sexually, but some species can also reproduce asexually through parthenogenesis or cloning. There are even some, such as the Cataglyphis cursor that can reproduce through either mode of reproduction.
Also, despite the fact that ants are eusocial and are characterized by reproductive division of labor, some ant species don’t rely on queens for reproduction.
In some queenless colonies for example, worker ants called gamergates have functional spermatheca and can also reproduce sexually. To add to that, there are also queenless ants,such as the Ooceraea biroi, otherwise known as clonal raider ants that are capable of asexual parthenogenesis.