Slave Making Ants
Biology 342 Fall 2010
By Zina Jenny and Joseph Perry
Mechanism
What allows them to do this?
|
Polyergus breviceps has specialized in raiding other colonies to such an extent that their mandibles are no longer suitable for the normal activities of a worker. They are specially designed to pierce the exoskeleton of another ant (3. Slave Raiding Ant) Even when placed in proximity to a food source, a Polyergus worker will starve to death without a slave to feed it (2. Wilson, E. O. 1975). Specializing to such a degree has allowed Polyergus to become brutally efficient at conducting raids and cutting through defenders, but unable to dig a nest and care for its young. |
|
Formica subintcgra and Formica pcrgandei have a different tactic. They produce "remarkably large quantities of decyl, dodecyl and tetradecyl acetates." (2. Wilson, E. O., 1975). Normally, these are used as alarm pheromones. A worker who receives it will go into a panicked nest defense mode. However, both of these Formica enslaver species take advantage of the fact that if a worker is exposed to a large enough concentration of these chemicals, she will become confused and erratic. Whenever the enslavers encounter resistance from a colony, they spray these pheromones on the opposing group. It both attracts more of the enslaver ants and throws the defenders into disarray.
|
The other form of slave making ants is not through nest raids and larvae thievery, but through usurping the old queen. A Lasius claviger queen, for example, will attempt to gain entry to a target colony through evading or sedating any workers she encounters, and then assassinates the resident queen (4. Social Parasitism in Ants). The Polyergus breviceps queen enters the host nest and is attacked by their workers. The instant she engages the host queen, the host workers stop attacking her. After she assassinates the queen, the P. breviceps queen rubs her body on the dead queen's body to pick up her scent before continuing on to conduct the colony (18. Johnson, A. 2001) |