About Diacamma rugosum (Le Guillou, 1842)
Diacamma rugosum, also commonly called the Bornean queenless ant or Asian bullet ant, is an ant species that belongs to the subfamily Ponerinae. This species occurs across many countries in Southeast Asia, and 20 distinct subspecies are currently recognized for it. Diacamma rugosum is distinguished as one of the only ant species that lacks a queen caste entirely. All reproduction within its colonies is carried out by workers, and every worker is fertile when it is born. Even so, reproduction is tightly controlled within the nest: only a single dominant fertile female, called a gamergate, lays all of the colony’s eggs. As soon as future workers reach the pupal stage, the gamergate renders them sterile by mutilating their vestigial wing buds. These resulting infertile workers, called callows, stay loyal to the existing gamergate and allow her to maintain control over the rest of the colony. This system reduces infighting within the colony by making usurpation of the gamergate effectively impossible, and the gamergate is only replaced when she dies of natural causes.
