A newly discovered parasitic behavior in certain ant species reveals a chillingly effective method of colony takeover: manipulating worker ants into killing their own queen. Researchers have documented how queens from Lasius orientalis and L. umbratus induce worker ants from L. flavus and L. japonicus colonies to commit matricide, securing the throne for themselves. This marks the first known instance of a third party benefiting directly from the death of a queen ant.
The Mechanism of Control
The parasitic queens infiltrate host colonies by first mimicking the colony’s scent, deceiving workers into accepting them as one of their own. Once accepted, the invading queen approaches the resident queen and sprays her with a chemical substance that incites a violent response from the workers. This leads to the host queen’s death, often within hours or days, depending on the persistence of the parasitic queen.
Chemical Warfare: The Role of Formic Acid
The inciting chemical is strongly suspected to be formic acid, a common irritant used by ants for defense. While the exact mechanism is still under investigation, researchers are exploring whether formic acid alone is sufficient to trigger matricide, or if other, yet unidentified chemicals are involved. One L. umbratus queen required only two sprays to instigate the attack, while another L. orientalis queen sprayed her victim 16 times over 20 hours before the workers dismembered the host queen after four days.
Evolutionary Advantage
This behavior represents a unique evolutionary tactic. Unlike other parasitic ants that directly kill the host queen, these species manipulate the colony’s own workers to commit the act. This may reduce the risk of injury or death for the invading queen. Christine Johnson, a behavioral ecologist at the American Museum of Natural History, suggests that this indirect approach could be an evolved strategy to minimize personal risk during takeover attempts.
Uncertain Succession
However, even successful matricide does not guarantee a smooth transition. The parasitic queen may be accepted by the colony, but there is no guarantee that the workers will adopt her offspring. This suggests that while the parasitic queen can seize control through manipulation, long-term survival still depends on the colony’s acceptance of her reproductive efforts.
This discovery underscores the complex and often brutal dynamics within ant colonies, where deception and manipulation can be just as effective as brute force in securing dominance
