1985] 
Pamilo, Crozier, & Fraser — Rhytidoponera 
219 
Ants were taken from the mature nest in two groups which were 
kept separate. The excavation took place during the middle of the 
day, with surface temperatures in excess of 45 C, so that no ants 
would have been expected to be absent foraging. We first extracted 
ants by “fishing” them from the nest entrance using straws. When no 
more ants could be obtained by this method, we dug the nest up, 
carefully checking all the side tunnels for ants as we went. Fishing 
yielded 192 ants and digging 245. The excavated ants consisted of 
107 mature ants and 138 young ones (as determined by their exoske- 
letons being soft and them lacking abdominal white or yellow 
bodies). We also found 243 cocoons and 1 1 larvae. Of the cocoons, 
235 contained worker pupae, one contained a male pupa, and seven 
had unclassifiable larvae or prepupae. 
The adult ants were dissected and checked for ovarian status and 
whether or not the spermatheca (sperm storage device) contained 
sperm. All of the young ants were found to be non-inseminated 
upon dissection, and also lacked corpora lutea. Their ovaries were 
either quite undeveloped, or very poorly developed in terms of pos- 
sessing oocytes in the ovarioles. The results of dissecting the old ants 
are shown in Table 1. Inseminated ants occurred significantly more 
often among the ants obtained by digging than those obtained by 
fishing (G = 37.26 (Yate’s correction), p < 0.001). The one insemi- 
nated worker caught by fishing was unusual for an inseminated 
worker in having no empty ovarioles, but this state is the predomi- 
nant one among uninseminated workers. We therefore tentatively 
discount this ant as an established egg-layer, leading to an estimate 
of 22 egg-layers, or 7.4% of the worker force. 
Pooling empty-ovariole classes 1-5 reveals marked differences in 
ovarian status between the various categories of ants shown in Table 
1. Thus there is a significant difference among the uninseminated 
ants between those collected by fishing and those collected by dig- 
ging (X 2 = 14.6, p < 0.001), and, among the ants collected by dig- 
ging, between those inseminated and those not (X 2 = 74.7, p < 
0.001). The uninseminated ants collected by digging had, on aver- 
age, less-developed ovaries than the uninseminated ants collected by 
fishing. The inseminated ants are characterised by belonging to the 
classes with intermediate (1-5) numbers of empty ovarioles, and 
also had an intermediate number of oocytes per ovariole. 
The incipient colony examined was discovered through carrying 
being observed to it from an established nest about 5 m away. The 
