26 o 
Psyche 
[June 
Table I. Movement by a swarm of Stelopolybia areata on four successive 
days. 
Terrain Height of Characteristics 
Date Time Direction Distance crossed bivouac of new site 
4/II 1530 WSW 72m 
5/II 1730 NW 77m 
6/II 1615 W 100m 
7/II 1650 NNW 70m 
along fence, 
then across 
tall grass 
and weeds 
tall 2nd 
growth, across 
arroyo into 
pasture 
pasture ; 
across brushy 
arroyo 
tall 2nd 
growth, along 
dirt road ; 
across road into 
partially logged 
forest 
4m tangle of lianas on 
trunk of large tree. 
5m split in trunk of 
dead tree. 
7m tangle of lianas at 
top of small tree. 
8m small twig near edge 
of crown of large tree. 
In the mornings activity of the swarm was relatively low, though 
at least some wasps could always be seen flying within a meter or 
two of it. Observations of the swarm with a 6oX telescope during 
these hours indicated that much of the activity was due to the arrival 
and departure of foragers. The approach of a forager would cause 
several wasps on the swarm to reach out toward the movement with 
their forelegs, while waving the antennae. When a forager landed 
she would immediately fold her wings, then often regurgitate liquid 
to these waiting workers. This behavior is identical to that observed 
on nests of the species. After such food exchanges the forager often 
disappeared into the midst of the swarm. The number of wasps 
engaged in foraging seemed to rise and fall with the 'appearance and 
disappearance of the sun in partly cloudy weather. 
Though data collected from other colonies at the same time of 
year suggest that 5-12% of the swarm population should have been 
queens (Jeanne, 1973), no queens were ever visible on the surface 
of the swarm. Their morphological distinctiveness from workers 
(Jeanne and Fagen, 1974) should have made them discernible had 
they been there. It is likely that queens remained near the center 
of the swarm. 
