1985] 
Wendelken & Barth — Pseudofemale behavior 
501 
cific mating tests performed by Roth (1970b). That pseudofemale 
behavior is shown interspecifically suggests that this response is not 
released by male sex pheromone or that males respond to a wider 
spectrum of male sex pheromones than do females. In the event that 
members of two species come into contact, it may be adaptive for a 
male to be able to disrupt heterospecific courtship if this increases 
the probability that a conspecific female will be available for copula- 
tion with that male. 
Thornhill (1979) reports an example of pseudofemale behavior in 
scorpionflies which functions to allow the pseudofemale performer 
to steal nuptial prey from rival males and then use the prey for 
copulation. There is a parallel to the present work in that the objec- 
tive of prey theft can be accomplished by several means including 
but not limited to pseudofemale behavior. 
Pseudofemale behavior in Blaberus, Archimandrita, and Byrso- 
tria is an example of a seemingly abnormal behavior turning out on 
closer inspection to be adaptive. It may be that pseudofemale behav- 
ior (whether or not accompanied by an actual attack) serves similar 
ends in other cockroach species. Future workers should keep in 
mind that pseudofemale behavior need not lead to an outright 
attack in order to contribute to the copulatory success of the per- 
forming male. In species with an overall lower intensity of male- 
male aggression, pseudofemale behavior might be exhibited without 
the overt aggression so prominent in the Tribe Blaberini. Simply 
occupying a displaying male’s abdomen prevents the female from 
copulating with the rival and buys time for the pseudofemale 
performer. 
Acknowledgements 
The research reported in this paper is part of a dissertation sub- 
mitted by P. W. W. for the Ph. D. degree. Thanks are expressed to 
J. L. Larimer, D. D. Thiessen, and T. H. Hamilton for reading an 
earlier version of the manuscript. The sources of the animals from 
which the stock cultures were derived are as follows: B. discoidalis — 
F. A. McKittrick, Cornell University; B. parabolicus — L. M. Roth, 
collected in Brazil on Phase C of the Alpha Helix Expedition to the 
Amazon in 1967; B. giganteus — Harvard University culture origi- 
nally from L. M. Roth; collection by R. H. Barth and F. A. McKit- 
trick in Panama in 1962; culture from O. P. Breland, The University 
