Chalepoxenus brunneus, found in only one very small site in the Great Atlas of Morocco, represents a workless parasitic species which is derived from actively dulotic congeners ("degenerate slavemaker"). The host species is Leptothorax cf. marocanus. The C. b. queen apparently eliminates the host colony queen by stinging her. She also stings to death a considerable part of the host colony workers, but, different from the dulotic congeners, the C. b. queen then is accepted by the remaining adult host workers. The sexual production is queen-biased (sex ratio 0.43 male/female); mating presumably takes place close to the nest. We found no evidence for a female sexual pheromone, but the C. b. males react on the pheromone form poison glands of other Chalepoxenus species. The life history of C. b. parallels that of other "degenerate slave-makers" in the genus Epimyrma.