1986] Moffett— Oligomyrmex overbecki 111 
The most conspicuous difference between the minor worker sub- 
castes was that darkly pigmented non-repletes formed the bulk of 
the foragers. The repertoire data indicate several other differences in 
the frequency of behaviors (differences judged significant when p < 
0.05 with chi-square test). Callow workers carried and licked eggs 
with greater frequency than did darker colored minors, but carried 
large immatures less frequently than did the latter. In comparison to 
darkly pigmented minors, callows rarely fed on solid foods and 
rarely allogroomed other workers. They also regurgitated to larvae 
more often than did the darker subcastes, yet apparently seldom 
regurgitated to other adult ants (difference in frequencies was not 
significant in the latter case). 
Darkly-pigmented replete minors were intermediate between cal- 
low and non-replete minors in the frequencies of performance of 
many of those behaviors that varied most markedly between the 
minor subcastes. This suggests the possibility that these minors 
could be intermediate in age between callow minors (which were 
consistently replete) and non-replete minors. 
Majors rarely foraged. During my observations only four majors 
were seen outside the nest of the captive colony, and one major was 
observed on a foraging route near the nest entrance in the field. 
Major workers apparently only fed by regurgitation. 
The O. overbecki queen did not attract a large retinue of workers, 
but commonly one or two minors climbed onto her alitrunk or 
gaster. In addition, twice I observed replete minors briefly pulling 
on an antenna or mandible of the queen. Only rarely would a major 
climb onto the queen, and the density of majors was not noticeably 
greater near the queen than elsewhere. 
Occasionally a major, minor, or the queen briefly appeared to try 
to grip or bite immatures, most commonly large larvae (“nip at 
brood” in Table 1). The function of this behavior is unclear, for 
although consumption of brood by minor workers was common, 
this biting behavior was most frequently performed by majors and 
apparently never damaged the immatures. 
Larvae fed directly on fragments of insect corpses and from food 
regurgitated to them by minors. 
Foraging Pattern and Diet: During my field observations 
columns of minor workers extended at least 30 cm from the nest on 
