Pleometrosis

Pleometrosis is a biological term, primarily used in the context of social insect biology, referring to the independent colony founding strategy where multiple queens (gynes) cooperate to establish a new colony. This is in contrast to haplometrosis, where a single queen founds a colony alone.

In pleometrosis, the cooperating queens will typically rear the first worker brood together. This collaborative effort can lead to a faster initial growth rate of the colony and potentially a higher survival rate during the vulnerable founding stage, compared to colonies founded by solitary queens. This is because the collective labor of multiple queens can more efficiently forage, build nests, and defend against predators.

However, pleometrosis is often a temporary arrangement. Once the first worker brood emerges and the colony becomes established, competition between the co-founding queens typically intensifies. This competition often results in the death or expulsion of all but one of the original queens, a process sometimes referred to as queen elimination. The surviving queen then becomes the sole reproductive individual in the colony, a situation referred to as monogyny.

The reasons for the eventual elimination of all but one queen are complex and vary between species. Factors contributing to queen elimination can include differences in queen fertility, aggressive interactions between queens, and worker preferences for a particular queen.

Pleometrosis is observed in a range of ant species and some wasp species, where it represents an alternative colony founding strategy that can be beneficial under specific environmental conditions or ecological pressures. The success of pleometrosis depends on a balance between the initial benefits of cooperation and the subsequent costs of competition among co-founding queens.