Overview
- Newly mated Lasius orientalis and Lasius umbratus queens infiltrate related species’ nests after stealing the host colony’s odor to pass as nestmates.
- Once inside, the invader sprays the resident queen with an irritant that provokes workers to attack her, with researchers hypothesizing the fluid is formic acid pending chemical confirmation.
- Laboratory videos captured the full takeover sequence, including invaders spraying and retreating as workers progressively mutilate and kill their queen.
- Species-specific patterns emerged: an L. umbratus queen needed only two sprays for a swift kill, while an L. orientalis queen sprayed roughly 15–16 times over about 20 hours before workers finished the job days later.
- After the host queen’s death, the parasite is accepted, begins laying eggs cared for by host workers, and researchers plan tests to verify the spray’s chemistry and assess how widespread this tactic is.