350 
Psyche 
[December 
appeared to be a dragger-follower-dragger sequence. With those 
exceptions no dragging or following behavior was observed during 
the afternoon while both of us were constantly present. By 4:15 PM 
the majority of wasps were at the new nest site, though until 5:40 PM 
a few wasps were constantly at the old swarm site. 
There was no convincing evidence that the wasps used a trail of 
chemical spots to orient to the new site or that the nest site itself was 
chemically marked by Richards’ gland. The limited dragging on 3 
prominent leaves resulted in no systematic follower visits, with the 
exception noted above. Since polybiines are able to learn the location 
of food even a hundred meters away from the nest (Forsyth 1978), 
foragers active before the raid must have been familiar with land¬ 
marks within 10 m of their old nest. It, therefore, seems probable that 
many wasps could have learned the short route to the new nest site 
during the 2 hr before the emigration. The hovering wasps along the 
path to the new nest site at the peak of the emigration could have 
guided any naive wasps. It is also possible that pheromone from 
Richards’ gland or some other source provided an aerial plume for 
orientation, although we saw no evidence of this in the behavior or 
posture of the wasps. Unfortunately, we did not record the wind 
direction at the time, but the prevailing winds are from the east to 
northeast or at a right angle to the flight path. 
Another swarm, Protopolybia exigua binominata (Schulz) (colony 
V-346, Panama), also appeared to move to a new nest site without the 
use of a pheromonal trail. Immediately after the wasps were experi¬ 
mentally evicted from their nest (by placing a few army ants near the 
nest), several wasps dragged their gasters along the edges of leaves 
close to the abandoned nest. The tip of the gaster did not touch the 
substrate, but the distal sternites contacted the leaf as in typical 
dragging behavior. By 5:30 PM, 3 hr after the wasps had been ousted 
from their nest, the swarm of about 200 had consolidated on a nearby 
leaf, and the wasps were flying from the swarm into the distance. The 
next day at 9:35 AM there were many wasps landing on various leaves 
near the swarm. No dragging or following behavior was observed; the 
wasps merely landed momentarily on leaves. The new nest was 
located on the underside of a leaf only 2-3 m from the swarm leaf and 
about 1 m higher. There were many intervening leaves between the 2 
sites, and the wasps did not follow any one path through the vegeta¬ 
tion to get to or from the new nest site. By 9:45 AM the old swarm site 
