Slave-making Ants*
Protomagnathus americanus
Slave-making Ants are a fascinating and rare insect species--and so
small, you are not likely to find them unless you know where to look!
The species’ name comes from its practice of a queen raiding the nests
of other ant species, killing or driving off the worker ants, and raising
both Slave-making and host larva in her new nest. The foreign young,
or ‘slaves,’ then mature and assume the colony chores, while the Slavemaking worker ants are busy raiding other colonies.
The population cannot sustain itself without slaves!~
From left to right: Two dark Slave-making Ants interact with light-colored host
ants (courtesy of C. Johnson); a close-up
of this fascinating species (both courtesy of NC State University); a group
of Slave-making ants raiding another
colony (courtesy of Scienceblogs.com).
At least two species of Slave-making Ants live in the cavities of sticks, acorns, and other tree nuts at
Niquette Bay State Park. P. americanus is the more common species of the two, and its primary host is
the small, black ant, Temnothorax longispinosus. The P. americanus nest consists of approximately 10 Slavemaking Ants and 30-60 hosts, or slaves, who are responsible for gathering food, grooming and feeding
larvae and queen, and defending the colony against attacks.
Because Slave-making Ants don’t know how to tend to the queen, raise young, or find food, the
population cannot sustain itself without slaves. Instead, the Slave-making worker ants can only raid other
colonies, which they do approximately 6 times each year! As of now, the Slave-making Ant population is
known to be steady at Niquette Bay State Park, while their host ant species is on the decline.
So the next time you visit Niquette Bay, think about the many tiny ants living in
sticks and acorns around you-- and wonder how many of them are being held
captive by Slave-makers!
*Information courtesy of Dr. Vickie Backus, Middlebury College, and Dr. Joan Herbers, Ohio State University, and
Herbers and Foitzik 2002 “The Ecology of Slavemaking Ants and Their Hosts in North Temperate Forests” Ecology
83:148-163.
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