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Psyche 
[Vol. 91 
1.4- 
1.3- 
workers 
\ 
queens 
09 LO U L2 
thorax width (mm) 
Fig. 1. Bivariate plot of morphological measurements for workers and queens. 
Si/e of Tilled circles indicates, in order of increasing si/e. 1, 2, 3. 4, and 5 or more 
individuals. Workers: n=136. slope=0.74, correlation=0.82. Queens: n=33, slope= 
0.77, correlation = 0.89. Data are from two colonies. 
WORKERS 
A total of 6823 behavioral acts were performed by workers and 
recorded over a period of 20 hours. These are presented by category 
in Table 1. Workers performed 31 types of acts, and, using the 
methods of Fagen and Goldman ( 1977), and Bulmer (1974), a true 
repertoire size of 3 1 was estimated. The range of the 95% confidence 
interval was less than 1 act. It must be emphasized that this level of 
accuracy applies only to the context in which the ants were 
observed. Undoubtedly, other behaviors would be expressed under 
other conditions, such as attack. Also, behaviors that are very rare 
or that are partially suppressed under laboratory conditions may 
not be recorded. Egg laying, for example, was not observed during 
this study. The following worker behaviors listed in Table 1 are 
treated in greater detail below: abdominal trophallaxis, transfer of 
liquid food (^regurgitation, oral trophallaxis), self-grooming, fate 
of infrabuccal pellets, excavating, and antennal tipping. In addi- 
tion, several behaviors not included in the ethogram are discussed: 
stridulation, defense, and miscellaneous leg movements. 
