Overview
- The peer‑reviewed report in Current Biology (November 17) documents parasitic queens infiltrating related colonies and provoking workers to kill their resident queen.
- Lasius orientalis and Lasius umbratus gain entry by acquiring host scent, then approach the queen and spray a foul‑smelling abdominal fluid that redirects worker aggression.
- Researchers hypothesize the spray is formic acid acting as a deceptive danger cue, though the chemical identity and sensory mechanism remain to be verified.
- Takeovers differ by species: L. orientalis required roughly 15 sprays over about 20 hours with the queen dying four days later, while L. umbratus needed only two sprays to trigger a rapid fatal attack.
- After the host queen’s death, the invader is typically accepted and begins laying eggs; the behavior was captured in controlled tabletop colonies and builds on citizen scientist observations by Taku Shimada.