14 
Psyche 
[Vol. 89 
larvae taken directly from the Pheidole colony were all dead after 
two weeks. On the other hand all of the larvae from the Cerapachys 
colony were obviously still alive after two weeks, many of them 
moving their mouthparts slightly. These findings clearly demon- 
strate that Cerapachys can store living prey larvae for a considerable 
period of time. This food storage system appears to enable Cera- 
pachys to stay inside their nest for longer intervals. They evidently 
do not conduct raids as long as a good food supply is present. The 
following experiments were designed to test this hypothesis. 
One day after the Cerapachys colony B had conducted a raid on 
Pheidole all prey larvae were removed. As a control I manipulated 
colony A in the same way, but the prey larvae were immediately 
returned to colony A. A few days later I observed scouts of colony B 
in the arena, where I had provided a nest tube with a fraction of a 
Pheidole colony, and within a period of 4 (test 1) and 7 days (test 2) 
colony B had conducted another raid. In the control colony A I 
noticed a worker briefly leaving the nest tube only once and then 
without venturing far into the arena. Although a tube containing 
Pheidole workers and brood was also provided in the arena of 
colony A, this colony did not conduct another raid until its supply 
of prey had declined considerably. 
Emigration behavior 
Although it is still an open question whether the Cerapachyini are 
nomadic, Wilson (1958, 1971) and Brown (1975) suggested that 
nomadism in the ant-preying cerapachyine species could well be 
adaptive to avoid depleting the food supply in a given neighbor- 
hood, just as it is in the army ants. This assumption of a nomadic 
life style is further supported by Brown’s observations that the nests 
of many cerapachyine species appear to be impermanent, and that 
the “brood show a strong tendency to be synchronized, like those of 
army ants and nomadic Ponerinae”. Brown (1975) also pointed out 
that the larvae of the Cerapachyini have a slender and cylindrical 
shape (G. C. Wheeler and J. Wheeler 1964), which makes them easy 
to transport longitudinally under the bodies of workers in the 
manner of other predatory and nomadic ants, such as Eciton, Aenic- 
tus, Dorylus, Leptogenys and Onychomyrmex. Although I was 
unable to demonstrate periodic nomadic behavior of Cerapachys in 
