Dulosis

Dulosis is the presence of permanent parasitism with slavery.

The biology of Temnothorax muellerianus and Polyergus rufescens provide representative accounts of dulosis.

Note that slave-making ants show wide variation in the degree of degeneracy of the worker caste. At one end of the spectrum (facultative dulosis), represented by Formica sanguinea, workers are self-sufficient, conduct all of the custodian tasks of the colony on their own and can easily survive without the support of slaves. In intermediate forms, termed "obligatory slavemakers", workers have a very limited behavioral repertory, but are behaviorally and often morphologically specialized for fighting and slave raiding. They are completely helpless without their slaves and are permanently dependent on regular replenishment of their slave stock through raids on host species colonies. At the other extreme, the term "degenerate slavemaker" has been coined for species that have secondarily lost their worker caste, or reduced its number, and hence can no longer conduct slave raids. Examples of degenerate slavemakers are Temnothorax kraussei (workers reduced to a few, or completely absent), Temnothorax corsicus and Temnothorax adlerzi (both workerless; all three belong to former genus Myrmoxenus), and Temnothorax brunneus (workerless, former genus Chalepoxenus).

Degenerate slavemakers are distinct from workerless inquilines in that the queens of the degenerate slavemakers kill the host colony queen by throttling (former Myrmoxenus species) or stinging (former Chalepoxenus species), while in workerless inquilines the queens live in queenright host colonies. Evolutionarily, degenerate slavemaking seems to have arisen fewer times than workerless inquilinism, with degenerate slavemakers most closely related to other dulotic species (thus previously being placed together in genera such as Chalepoxenus, Myrmoxenus or currently in Strongylognathus), while workerless inquilines have tended to arise independently of each other and are (generally) more closely related to their hosts than to other inquilines (for example Leptothorax kutteri and Leptothorax pacis with Leptothorax acervorum as the host species).