1971] 
W endelken & Barth — Parcoblatta 
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drummed it rapidly with her maxillary palps, and walked across it. 
This first female initially made contact with the paper about 1.5 
to 2 minutes after its introduction and had remained upon it for 
about a minute when the other female arrived. The second female 
touched the paper with her antennae and showed the same behavior 
toward it as the first female. Then there was some aggressive 
behavior between the two females. The second female drove the 
first one away and then proceeded to move around the paper, 
palpating it and waving her antennae gently. More work is clearly 
needed to confirm the hypothesis of volatility of the male sex 
pheromone in this species. 
Aggressive Behavior 
Two examples of male-female aggression were observed. In one, 
a female approached a male from in front of him. The male, in 
what appeared to be an aggressive gesture, jerked his head toward 
the female and she decamped. In the second case, a male and 
female made antennal contact, facing each other. The female lunged 
toward the male and then ran off. The male gave chase for a 
short distance. 
In addition to the aggressive female-female encounter described 
above, an observation was made in which two females were facing 
each other and antennal fencing. One female lunged toward the 
other and chased it away. 
Female aggression directed toward a copulating pair was observed 
in two cases. In the first case, a female (with protruding egg case) 
twice in rapid succession approached and jumped on top of the 
copulating pair — primarily on the dorsum of the copulating female 
— • and then glanced off rather rapidly. Later this female twice 
butted into the side of the copulating female but did not jump on 
it; the copulating female moved the pair several inches away. In 
the second case, a female antennally contacted a copulating pair and 
then, about a second later, charged toward the center of the pair 
and bumped them. 
The fact that aggression was never observed between males may 
very likely be due to the fact that only 2 or 3 were ever employed 
during observations, greatly decreasing the chances of interaction. 
Summary 
In Parcoblatta fulvescens , the volatile female sex pheromone plays 
a very prominent role in the release of the male’s courtship behavior. 
Olfactory reception of the female sex pheromone releases in males 
