1979] 
Chadab & Rettenmeyer — Social Wasps 
351 
had been abandoned and only an occasional wasp appeared there 
afterward. Several wasps at the new nest site were observed dragging 
their gasters on the edge of the new nest leaf after 10:00 AM. 
In only 10 min most of the wasps flew to the new site, less than 3 m 
from the swarm. The short distance and the large number of wasps 
enhanced the probability that the wasps were following other individ¬ 
uals visually or by an aerial pheromone trail. No systematic visits, 
marking, or antennation at specific sites were observed. Forsyth 
(1978) noted that visual cues may be important or used in conjunction 
with a pheromone trail during short movements of Polybia occiden- 
talis (Olivier). 
The shortest distance for a swarm emigration observed by Jeanne 
(1975) was 70 m and Naumann (1975) reported distances of 3-33 m. 
Perhaps a continuum of behavior exists; for short distances the wasps 
rely on learning and visual cues for orientation and as the emigration 
distance increases they rely increasingly on chemical-spot trails. 
Honey bees also shift their orientation-communication system as the 
distance to food increases (Frisch 1967:57). 
Although Jeanne’s (1980) recent research supports that secretions 
from Richards’ gland deposited during dragging behavior form a 
scent trail, such behavior is not restricted to trail formation. The 
dragging at the new nest site by P. exigua well after the emigration 
was completed may have been an ill-timed part of the emigration 
process, or a method of reinforcing recognition of a new nest. Drag¬ 
ging behavior was also observed in a context other than swarm 
emigration in Polybia scrobalis Richards. 
When army ants were placed on or held near 2 nests of Polybia 
scrobalis (colonies V-377, V-443, Panama), 50-100% of the adults 
flew. Wasps started returning to the nest immediately, and 10-20% of 
those returning dragged their gasters in the typical manner on the nest 
carton, nest leaf, adjacent leaves, and occasionally on their nest- 
mates. This response could not be elicited by holding Paraponera 
clavata (F.) or Ectatomma tuberculatum (Olivier) next to the wasps’ 
nest, but on one occasion when a worker of Camponotus sericeiven- 
tris (Guerin) was held up to the nest a similar evacuation was accom¬ 
panied by dragging both before and after flight. Such frequent 
dragging behavior by alarmed wasps and wasps which have left their 
nest for less than one minute was not observed during similar experi¬ 
ments performed with 30 species of polybiines in Panama and Ecua- 
