302 
Psyche 
[September-December 
monogynous system such as Polistes, usurpation may be accomplished 
by simple mechanical domination of both workers and reproductives 
by the invading female. In this case, in which there are many resi- 
dent workers, usurpation cannot proceed simply by aggression. It is 
probable that the invasion is accomplished by deception based on 
colony odor. The usurping female was not at either colony for 
several days. This may have allowed loss of colony odor and facili- 
tated her acceptance into the colony. 
The dominance behavior and aggression described previously may 
have broader significance than simply the triggering of usurpation. 
Inter-queen competition appears to be pronounced in small colonies 
to the extent that it may alter the social structure. Most small 
Metcipolybia cingulata colonies rapidly become effectively monogynous 
(Forsyth, in prep.). Eberhard (1973) has reported this phenomenon 
in M. docilis and M. aztecoides. She found that monogyny was pro- 
duced by worker persecution of all reproductive females but one. 
My observations suggest that monogyny in small colonies may also 
be the result of inter-queen aggression. Polygyny develops when 
colonies become large (Forsyth, in prep.). In a proximate sense, 
the occurrence of many reproductive females in the large colonies 
may simply reflect the ineffectiveness of dominance in large colonies. 
In an evolutionary context, the importance of inter-queen dominance 
will vary as a function of colony level selection pressures and in- 
breeding, a relationship yet to be quantified in the field. 
Acknowledgements 
I would like to thank Harvard University for financial support, 
Dr. E. O. Wilson for helpful suggestions and Ken Miyata and 
Richard Webster for assistance in the field. 
Literature Cited 
Eberhard, M. J. W. 
1973. Monogyny in “polygynous” social wasps. Proc. VII Cong. IUSSI, 
London, pp. 396-403. 
Forsyth, A. B. 
1976. Interchange between colonies of the social wasp M etapolybia 
cingulata (Hymenoptera : Vespidae: Polybiini). Behavioral Ecol- 
ogy and Sociobiology [Submitted]. 
Janet, C. 
1903. Observations sur les guepes. C. Naud, Paris. 85 pp. 
Richards, O. W. and M. Richards. 
1951. Observations on the social wasps of South America (Hymen- 
optera: Vespidae). Trans. Roy. Entomol. Soc. London 102: 1-167. 
