A princess pheromone allows ants to identify their queens, says a new study published in the journal Animal Behaviour.
Indian jumping ants (scientific name: Harpegnathos saltator) spot their queens thanks to a princess pheromone, which also helps them to get rid of unwanted queens!
Before an ant becomes a queen, it first needs to go through the larval stage. Then, when the right time comes, ant workers will provide the larva with the resources required to transition into a queen. On the other hand, if a larva tries to mature into a queen before the right time, it will be physically coerced into remaining a worker, and no coronation will ever happen to it! All of this is controlled by the newly-discovered princess pheromone.
The pheromone has one job: notify the ant colony when a larva is initiating development to become a queen. This is the first time that such a role has been attributed to an ant pheromone, whereby the latter influences ant colony behaviour, explains lead author of the research, Clint Penick from North Carolina State University. Otherwise, the conventional function of pheromones in ants is to establish communication between the insects.
Colonies of H. saltator rear their queens during the first summer rains, after which the monarchs will leave upon reaching maturation to mate with winged males to create new colonies of ants. At the right timing, the princess pheromone will be released by the larvae to stimulate the ant workers to ease the development of the queens. These life events are to follow a specific timing because the mating flight cannot happen at any other time, and if an ant larva attempts to transform into a queen during a wrong season, colony resources will be misused. Hence, to avoid this, certain actions are set into motion: an ant larva developing into a queen at an unwanted time releasing the princess pheromone will cause stress to worker ants which will be prompted to bite the wannabe-queen larva so that the latter remains a humble worker. Find a video of workers assaulting these larvae here.
Another scenario involving ant workers chewing on potential queens happens when there are too many developing queens than the colony can support, regardless of the timing being right, explains Penick.
According to Penick, signals like the princess pheromone are critically important for social insects because they need a strategy to ascertain that there is a sufficient number of ant workers in their colonies. If they were not to not cater for this, they would end up with too many queens, and not enough workers, and their community would fracture.
These findings, thus, gives a better understanding concerning the differentiation of castes within the Indian jumping ant society. They also allow us to look deeper into the complex biology mediating the behaviours of social insects. Penick and his colleagues believe that this mechanism might be common among such insects, but more research needs to be conducted to find out whether other ant species also have some form of princess pheromone.