300 
Psyche 
[September-December 
Moreover, dominance behavior has been poorly studied in polygynous 
wasps. Herein, a set of observations on an instance of usurpation in 
a tropical polygynous wasp, Metapolybia cingulata (Hymenoptera : 
Vespidae: Polybiini) and the dominance interactions that preceded 
usurpation seem worthy of a separate presentation. 
Materials and Methods 
The observations presented here were made during a three month 
study of Metapolybia cingulata in western Ecuador. 
A group of colonies were modified to permit close observation and 
were marked for identification in the manner described by Forsyth 
(1976). The two colonies discussed in this report were relatively 
small and young. Colony C initially contained 27 adults and a comb 
area of no X 85 mm. Colony F initially contained 55 adults and 
a comb area of 120 X 80 mm. On the basis of cell reusage, colony 
F was older than colony C. 
Metapolybia cingulata , like most polybiines, lacks strongly differ- 
entiated morphological castes, and it is usually necessary to dissect 
females to conclusively distinguish workers from queens (Richards 
and Richards, 1951). However, there are differences in queen and 
worker behavior which allows one to categorize individuals ; for 
example, workers groom queens but not each other. The observa- 
tions presented here were derived from a continuing long term study 
in which the reproductive roles were inferred behaviorally rather 
than by dissection. 
Observations 
Strong dominance interactions were first observed in colony C 
on June 28. Two females were involved which are designated DDT 
and YA. DDT was a young female which had eclosed on June 20. 
YA had been present in the colony since the initiation of the study 
on May 23. DDT was very attractive to the workers who fre- 
quently groomed her, particularly about the abdomen. YA was 
much less frequently groomed, but clearly occupied a dominant role. 
She frequently postured in the aggressive wing-spread position and 
was often the recipient of trophallaxis. 
On June 28 I observed YA approach DDT and grab with her 
forelegs the head of DDT. DDT broke the hold and moved away. 
Shortly after, while DDT was being groomed, YA again approached 
and attempted to bite the abdomen of DDT. DDT responded with 
an abdominal stinging motion (sting retracted) but was physically 
