1985] 
Wendelken & Barth — Pseudofemale behavior 
497 
his opponent. This causes the displaying male to run rapidly for- 
ward in an attempted escape. (3) Another form of assault occurs in 
which a male attacks a second male which is performing a full wing 
raising display. Before the female has an opportunity to respond, 
the attacking male leaps onto the displaying male’s abdomen (this 
does not resemble the elementary pattern of pseudofemale mount- 
ing and feeding), attempting to bite him (particularly his raised 
wings). Such an action causes the displaying male to run off rapidly. 
(4) A male may disrupt a copulation sequence in progress by attack- 
ing as a female mounts a displaying male. The attacker may break 
up the sequence by climbing onto the displaying male’s abdomen 
from the side, pushing the female off, and then biting his wings, 
causing him to run off. Or a male may directly attack the mounting 
female. (5) Attacks may be directed against copulating pairs. Typi- 
cally, the attacker jumps upon the copulating animals. Sometimes 
these attacks are focused at the juncture between the male and 
female. In two cases in B . craniifer, such attacks caused separation 
of a pair which had just assumed the opposed position. Apparently 
their genitalia were not as yet securely attached. Attacks on copulat- 
ing pairs commencing after the initial few seconds following 
assumption of the opposed position were never observed to cause 
separation of a copulating pair. The observed forms of male inter- 
vention in the courtship of other males are shown for each species in 
Table 1. 
In tests of interspecific sexual interactions in which females were 
presented with a choice of conspecific and heterospecific males, 
interspecific pseudofemale behavior was observed in three combina- 
tions. In one cross, a male B. giganteus mounted a displaying B. 
discoidalis male and bit his wings. Other forms of interspecific male- 
male aggression were observed between these two species. 
In another cross, B. giganteus males showed pseudofemale 
mountings of B. craniifer males and vice versa. In at least one case, a 
mounting B. craniifer male launched an attack directed against the 
wings of a displaying B. giganteus male. There was also reciprocal 
interspecific disruption of copulation sequences by males of these 
two species. 
In an intergeneric combination, Byrsotria fumigata males were 
observed mounting Blaberus discoidalis males. It was not observed 
whether these pseudofemale episodes were aggressive in nature. 
