For social insects such as ants, the queen is in charge of spawning, and worker ants perform non-breeding tasks such as childcare and foraging.However, in fact, worker ants in many species do not lay eggs even though they have the ability to lay eggs.Recent achievements in entomology have shown that this is because other worker ants are cracking down on selfish behavior (self-spawning).

　In this regard, the general theory (Ohtsuki & Tsuji model) submitted in 2009 predicts that selfish spawning of workers (worker ants) will be strongly mutually cracked in growing colonies, while cracking down in fully grown societies. Is expected to loosen and cause male production by workers.Verification with actual organisms was expected.

　This time, the research group used Togeo Hariari (inhabiting the main island of Okinawa) to observe crackdown behavior in a society in the growth and maturity stages.As a result, it was found that strong crackdown behavior occurs in the growth stage, but its strength weakens in the maturity stage.In addition, as a result of genetic analysis, it was found that males derived from worker ants are born at the maturity stage.These results strongly support the model's predictions and suggest that the evolutionary factors of crackdown behavior are the disadvantages of worker ant breeding to society as a whole.

　Unlike the static theory that does not consider the size of the society, the results of this research capture the social maintenance system as a fluctuating society, and the evolutionary mechanism of the insect society will be further elucidated in the future. There is expected.

Paper information:[Proceedings of the Royal Society B] Social enforcement depending on the stage of colony growth in an ant