1982] 
Traniello — Amblyopone pallipes 
73 
Behavioral Act 
Workers (16) 
N=2525 
Queens (2) 
N=158 
40. Pinch larvae 
0 
0.0063 
41. Cannibalize larva 
0.0170 
0.0380 
42. Discharge subpharyngeal 
pellet 
0 
0.0063 
Totals: 
1.0 
1.0 
infrequently in A. pallipes. During this behavior the body is raised, 
the gaster is curved forward, and with the mandibles agape the 
antennae are held forward with their terminal funicular segments 
slightly inclined toward each other. The significance of antennal 
tipping is unknown, but it appeared to be part of a grooming 
sequence. Vibrational displays were given by workers if the nest wall 
was breached or if an individual was mechanically disturbed. If the 
stimulus was intense enough, other workers would show the same 
vigorous jittering behavior, consisting of rapid vertical movements 
of the head and thorax. This behavior had the effect of producing a 
general arousal within the colony and resulted in an increase in the 
number of workers appearing at the source of stimulation. In the 
case of nest damage, building behavior eventually occurred but did 
not immediately follow. This signal appears to be a primitive form 
of mechanical communication, in which alarm is propagated di- 
rectly through body contact. A similar vibratory display has been 
documented in A. australis (Holldobler, 1977). 
Workers and queens of A. pallipes have retained a number of 
behaviors that appear to reflect their wasp ancestry. Queens were 
seen grasping larvae and squeezing them in the neck region with 
their mandibles, thus causing them to regurgitate a droplet of clear 
liquid which they then consumed. Workers were never observed to 
regurgitate with other workers, queens, or larvae, and all individuals 
fed directly on prey. Aggression was observed between workers and 
queens. An aggressive display typically consisted of opening the 
mandibles and rising up on the extended legs. This behavior was 
usually exhibited by queens in the area of the egg pile and seemed to 
produce avoidance in contacted workers. These observations raise 
the question of whether queens maintain their reproductive status 
through behavioral dominance or inhibitory pheromones. 
Polyethism. Studies on the division of labor within the worker 
caste have revealed that temporal castes are absent in the species. A 
