Recruitment behavior in the ant genus Polyrhachis (Hymenoptera, Formicidae)

We present a detailed behavioral analysis of the signals involved in recrui tment of 11 syntopic Polyrhachis species from West Malaysia. We found a con siderable variety of recruitment techniques, including "social carrying beh avior," "tandem running," "group recruitment, "and a technique which we cal l "leader-independent trail communication." The latter mode superficially r esembles "chemical mass communication" (sense Wilson, 1962). All these recr uitment techniques involve mechanical invitation behavior inside the nest, comprising back-and-forth jerking or pulling movement often combined with a sideways waggling. However, not in all cases of leader-independent trail c ommunication is a mechanical invitation behavior obligatory. The trail pher omone of all investigated Polyrhachis species originates from the hindgut. Only in the tandem running P. proxima do additional secretions from the poi son gland appear to be involved in tandem calling.