PSYCHE 
Vol. 92 
1985 
No. 2-3 
BEHAVIORAL NOTES ON THE 
ASIATIC HARVESTING ANTS 
ACANTHOMYRMEX NOTABILIS AND A. FEROX* 
By Mark W. Moffett 
Museum of Comparative Zoology 
Harvard University, Cambridge, Mass. 02138 
The workers of some ants fall into two size classes, each with a 
distinctive morphology and without intermediates. This condition, 
known as complete dimorphism, has arisen independently at least 
seven times among ants (Wilson, 1971). Perhaps the most dramatic 
examples of the dimorphic worker condition are found in the myr- 
micine genus Acanthomyrmex. One of the most startling species is 
A. notabilis (fig. 1), in which the trunk and gaster of the major are 
only fractionally larger than those of the minor caste, while the head 
is relatively enormous. In life, the head is thrown back over the 
trunk, and in fact much of the trunk fits conveniently into a cavity in 
the underside of the head capsule. The trunk is therefore virtually 
concealed even when the animal is viewed from the side. Moreover 
the waist and gaster are typically drawn up close to the body and 
are thus inconspicuous. Indeed, an observer’s initial impression of a 
live A. notabilis major will likely be one of a “walking head.” 
Eleven species of Acanthomyrmex ants have been collected (Mof- 
fett, in prep.), all endemic to the Oriental region. To date no infor- 
mation pertinent to the behavior and ecology of these rarely 
collected ants has been reported. I present preliminary findings con- 
cerning two species here. 
* Manuscript received by the editor May 10, 1985 
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