Intercastes, intermorphs, and ergatoid queens: who is who in ant reproduction?

Summary:

The terminology for ant females which are morphologically intermediate between “normal”, originally winged queens and workers teems with ill-defined terms, such as “ergatogyne”, “apterogyne”, or “gynaecoid worker”. The terminology proposed by Peeters (1991a) gets rid of most of these terms but fails to distinguish between sporadically occurring “intercastes”, reared due to “mistakes” in caste differentiation, and “intermorphic queens”, which are the ordinary female reproductives in many colonies of formicoxenine ants. A detailed examination of development, morphology, and occurrence of the latter suggests that intermorphic queens are more similar to ergatoid queens (sensu Peeters, 1991a) than to “intercastes”, and should not be comprised under the latter term.