Dominant males in the nest laying eggs regularly inspect and mark future competitors a chemical signal that causes the ants working to destroy pupae juveniles, perceiving them as the aggressor, say biologists in a paper published in the journal BMC Ecology.
Colonies of many species of social insects are composed of several castes that perform various tasks. So, working individuals caring for offspring and feed the colony, the soldiers defending it, and mature males and females are involved in reproduction.
Team of biologists led by Sylvia Cremer (Sylvia Cremer) from the Institute of Science and Technology of Austria in Klosterneuburg studying the social behavior of ants species Cardiocondyla obscurior, observing the behavior of adult males in the artificial nest.
According to researchers, these insects live in the tropical forests in the large underground ant. The males of these insects are divided into two groups — the dominant flightless birds that live inside the nest and fertilize the queen, and winged males leave the colony after a few days of birth. As a rule, in the nest can live only one dominant male — the emergence of a competitor is always accompanied by an adult ritual battle, in which one or both competitors die.
Kramer and her colleagues found that older dominant males used "fraudulent" methods to deal with competitors, minimizing the chance of damage with a few tricks.
Dominant individuals regularly patrol the parts of the nest in which the workers are grown larvae and pupae. Each ant caste has a unique smell, even in the form of larvae or pupae, allowing other members of the colony to determine their class association. Dominant males take this opportunity to highlight their future colleagues and timing of their release from the pupa.
Biologists have noticed that in some cases, they bite their fellow pupae and thus killed them.
"The old dominant males are able to distinguish the pupa, which contain future females, those from which hatched males. This was evident from the fact that they often bite" male "dolls and tried to mate with the" female "individuals. Yet they rarely acted thus because of the possibility to destroy the work of female doll by mistake, "- explained Kramer.
If a young male still managed to hatch, his older "friend" is trying to destroy it in the first two days of life.
At this stage, older males are two ways of getting rid of the competition. In some cases, they are marked with the juveniles with a special pheromone that ants usually sprayed other insects invading the nest. As a result, working individuals kill newborn males, perceiving it as an aggressor.
In addition, in the first two days of life of the young ant chitinous shell remains soft, allowing the dominant individuals easily bite through it and kill his rival without risk to their health.
Scientists believe that such a strategy of social behavior benefits the colony — is always present in the nest at least one mature male, and their number is at a minimum because of the aggressiveness.