Structural and functional changes of the Dufour gland in gynes of the amazon ant Polyergus rufescens (Hymenoptera, Formicidae)

Colony foundation by the slave-making amazon ant Polyergus rufescens requir es penetration of the young gyne soon after mating into a colony of the sla ve species. During this process, she uses decyl butyrate from her large Duf our gland as an effective appeasement allomone. The structural appearance a nd development of this gland shows a clear age-dependent evolution that is in line with its behavioural function. At the moment of eclosion, young fem ales have a gland with an empty lumen but thick lining epithelium, of which the active secretory cells are characterised by a well-developed Golgi app aratus, abundant mitochondria and smooth endoplasmic reticulum. The basal p lasmalemma shows deep in vaginations that facilitate the uptake of precurso rs from the haemolymph, while intercellular contacts display conspicuous in terdigitations in the apical cell part. During the first days of adult life , secretion starts to accumulate in the lumen. At the age of 3 weeks, the g land displays a large lumen filled with secretion and a thin epithelium tha t no longer displays secretory activity. By this time, the gynes are ready for penetration into a slave colony, being loaded with large quantities of the appeasement allomone that are necessary at this initial stage of the us urpation process.