122 
Psyche 
[Vol. 88 
Later in the evening (10:45 p.m.), lesser numbers of alate males 
were present, but inactive, on the ground at various locations. Over 
the next 3 weeks small congregations of males were seen around nest 
entrances, but never in such numbers or frenzied activity as during 
the large-scale swarm of 4 October. 
The Sydney University population of chalybaea consists princi- 
pally of worker-reproductive colonies, so the preponderance of 
males among alates is not surprising. The 1976 mating swarms 
apparently involved insemination of both workers and queens. Only 
one mated queen was found, however, and it remains unclear if 
queens mate predominantly in the vicinity of nest entrances or in 
separate rendevous sites. 
Given the limited number of successful matings observed, it is 
conceivable that the mating swarm had already passed a peak of 
activity at the time that observations began (10:15 a.m.). This is also 
suggested by the absence of workers in a sex pheromone-releasing 
posture (as described by Holldobler and Haskins (1977) for R. 
metallica). Such “calling” workers were observed in lab colonies of 
chalybaea , where the behavior occurred both inside and outside the 
artificial nest. The posture adopted was similar to that described for 
metallica (i.e., head and mesosoma lowered, gaster raised and 
arched, with tergites exposed). In addition, workers repeatedly 
rubbed the sides of the gaster with their hind tibiae, presumably 
facilitating release of pygidial (=tergal) gland pheromone. Such 
rubbing movements have been reported in Amblyopone pallipes 
queens (Haskins, 1979) but not previously in Rhytidoponera. 
A mated worker from one of the copulating pairs observed at Site 
A was isolated in a modified Janet (plaster-of-Paris) nest in the lab 
and fed on honey and Drosophila. On 1 1 November the first egg 
was seen, and by 21 December there were 2 eggs, 1 larva and 1 
worker cocoon. Just before the colony was terminated, in March, 
1977, this mated worker had produced three worker offspring (the 
first had appeared on 19 January 1977). This is perhaps the first 
record among the Formicidae of colony-foundation by a lone 
worker. However, as mentioned previously, there is no evidence that 
single workers found colonies in the field and it appears that they 
are always accompanied by an entourage of uninseminated workers. 
The inseminated dealate female, also collected on 4 October 1976, 
was kept under similar lab conditions for five months. The first 
worker appeared on 7 January 1977. At time of termination 
