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Psyche 
[Vol. 93 
Table 2. Observations on foraging activity of the queen and first eclosing workers 
in R. metallica colony #6280. Day #1 (3.iii. 1 984) is the day of first successful eclosion 
of a worker. 
Day # 
No. of adult workers 
in colony 
Foraging activity of queen and workers 
1-2 
1 (callow) 
Queen foraging. Worker confined to nest. 
7 
2 (1 callow) 
Queen foraging. Workers confined to nest. 
10 
4 
Queen took prey ( Drosophila ) at nest entrance. 
11-12 
4 
Queen foraging. Workers confined to nest. 
13 
4 
Worker foraging in arena (first time), captured a 
subdued Drosophila adult; queen removed prey 
from worker at nest entrance, then proceeded to 
forage in arena herself. 
14-17 
4-5 
Queen and one worker in foraging arena. 
22-27 
6-8 
Queen and several workers foraging and taking 
prey, the workers more active than the queen. 
28 
8 
Last observation of queen in foraging arena 
(thereafter queen confined to nest, and all 
foraging conducted by workers). 
Subsequent growth and development of queenright colonies 
The growth rates of the R. metallica colonies were rather slow 
and uneven, relative to that of R. chalybaea (Figure 1). One year 
after colony initiation, the two R. metallica colonies had worker 
populations of 41 and 27 individuals, respectively, while the R. 
chalybaea colony had a worker population exceeding 200. Since the 
colonies were fed ad libitum, food availability is not likely to have 
been a limiting factor in the slower growth of the R. metallica 
colonies. In fact, all three colonies grew at a rate faster than that 
inferred for incipient queenright colonies of R. chalybaea (and a 
related species, R. confusa Ward) in the field (Ward, 1981). 
The R. metallica colonies appeared to function similarly during 
the first year of development. Then a marked divergence took place, 
apparently due to queen infertility in colony #6280. In mid-October, 
1984 (week 56) this colony stopped producing eggs, and the amount 
of brood began declining. By mid-January, 1985 (week 66), with a 
population of 50 workers (and one male of unknown parentage), 
this colony contained no eggs or larvae, and only one cocoon 
(worker). On January 22, the queen was observed in a sexual calling 
posture (gaster raised, head and mesosoma lowered) inside the nest; 
