tending her and rearing her brood. As the parasite’s brood ecloses, the
colony’s worker force becomes a mixture of the two species. Later, as the
host workers gradually die off, the colony becomes a pure colony of
the parasite species, with no indication of its parasitic origin. In some
temporary social parasites, adoption can be either intra- or interspecific,
whereas, in others, it is strictly interspecific and obligatory. Temporary
social parasitism has been documented in various ant genera, including
Formica,Lasius,Acanthomyops and Bothriomyrmex (Hölldobler and
Wilson, 1990).Slavery
Slavery in ants, often referred to as dulosis, is a form of social parasitism
in which established colonies of the parasite species obtain functional
workers (‘slaves’) from other established colonies (Hölldobler, 1976;
Buschingeret al., 1980; Stuart and Alloway, 1982, 1983, 1985; Stuart,
1984; Hölldobler and Wilson, 1990; Topoff, 1997). Typically, slave
makers conduct what are referred to as slave raids, during which they
attack other colonies, kill or drive away the adults and appropriate the
brood. This captured brood is reared in the slave maker’s nest, and the
workers that eclose from it become functional members of the slave-maker
colony. In some cases, adult host-species workers are taken and enslaved,
a phenomenon referred to as eudulosis. Slave makers vary in their degree
of specialization; and their parasitic relationships may be either intra- or
interspecific and either facultative or obligatory. Obligatory slave makers
are often highly specialized social parasites, conduct dramatic, well-
organized slave raids and display a broad range of morphological,
behavioural and physiological adaptations for their parasitic lifestyle,
especially in terms of fighting and recruiting nest mates during raids.
Obligatory slave makers also tend to exhibit various degrees of
ineptitude in their ability to forage, to care for their brood and to perform
various other domestic tasks that are routinely performed by their slaves
(Wilson, 1975b; Dobrazanska, 1978; Stuart and Alloway, 1985; Mori
and Le Moli, 1988; Hölldobler and Wilson, 1990). Moreover, all known
obligatory slave makers are unable to found colonies independently
and must rely on some form of parasitic colony foundation. Typically,
this involves colony usurpation, similar to that seen in temporary social
parasites, with a newly mated slave-maker queen aggressively invading a
small host-species colony or colony fragment, capturing its brood and
subsequently being adopted by the eclosing host workers. In some cases,
the parasite is adopted by adult workers present in the host colony at the
time of usurpation (e.g. Stuart, 1984; Topoff, 1997).
Perhaps the most specialized and well-known slave makers are the
amazon-ants of the genusPolyergus(see Hölldobler and Wilson, 1990;
Topoff, 1997; and references therein). Five Polyergus species are
recognized:P. rufescensin Europe and North America,P. brevicepsand
P. lucidusin North America,P. nigerrimusin Russia andP. samuraiin
Japan and eastern Siberia. These slave makers parasitize ants in the genusSocial Parasitism in Ants 321