Parasitic queen ants that make the colony kill its own mother

When you start in myrmecoculture, the first thing you learn is how important the queen is: without her, the colony has no future. That is why a Japanese study describing how a parasitic queen gets worker ants to kill their own mother caught my attention so much.

The research, from the Institute of Biological Sciences at Kyushu University, documents for the first time how two parasitic species, Lasius orientalis and Lasius umbratus, take control of someone else's colony. The work, by Takasuka and colleagues, was published in Current Biology in 2025.

The process has several steps. First, the parasitic queen enters the colony of a related species, such as Lasius flavus or Lasius japonicus, and hides among the workers. Then she approaches the resident queen and sprays her with a fluid from her abdomen, probably formic acid, although that has not yet been confirmed chemically. The fluid does not kill her right away, but it changes her scent.

And here is the key: in these societies, scent identifies each member. The workers stop recognizing their queen, treat her as an intruder and kill her. Afterwards they accept the parasite without resistance and raise her offspring as if they were their own.

The story began with an amateur naturalist, Taku Shimada, who filmed the infiltration and the matricide in Lasius orientalis. The entomologist Keizo Takasuka saw an opportunity in that video and, together with him, designed a controlled experiment that confirmed the phenomenon. According to the paper, the tactic evolved independently in at least two species, so this manipulation of chemical signals may be more common than we thought.

Source: Muy Interesante