1971] 
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stances olfactory reception of the female sex pheromone combined 
with tactile stimulation of the male’s hindparts was sufficient to 
release the wing raising display and that tactile stimulation of the 
male’s hindparts inhibited turning. 
There were twelve observations in which a male on coming close 
to a female, but without contacting her, wing raised, turned, and 
backed. This represents approximately 20 percent of all observa- 
tions for which the events preceding display were recorded. In 
these cases the wing raising display, turning, and backing were all 
apparently released merely by olfactory reception of an intense con- 
centration of volatile female sex pheromone in the absence of any 
contact chemoreception or tactile stimulation. One of these twelve 
displays led to a successful copulation. 
If the female does not respond to the male’s display after a brief 
period, the male frequently will flutter his raised wings or pump 
and flutter them. This possibly serves to disseminate the male sex 
pheromone to a female who is not responding to the male’s display. 
Occasionally, after leaving the site of an unsuccessful copulation 
attempt, a male will locomote around with his wings still partially 
raised (10 to 30 degrees) for 30 seconds to one minute. 
3. Terminal events in the copulation sequence 
A receptive female responds to the male’s display with active 
mounting and feeding, moving in a forward direction over the male’s 
exposed abdominal tergites. If the male’s backing is poorly oriented, 
the female adjusts her position accordingly. When the female is 
about two-thirds forward over the male’s abdomen, the male begins 
probing extensions with his abdomen which is now concave on the 
dorsal surface, the abdominal tip contacting the female’s under- 
surface. The female advances with her feeding activities to the 
region of the first tergite at which point genital connection is 
achieved. The female then performs a turning movement which 
results in the animals facing away from each other in the 180 
degree opposed position which is maintained for the duration of 
copulation. In this position the male’s wings slightly overlie the 
abdominal tip of the female, covering her cerci. 
4. Behavior of copulating pairs 
Five accurately timed copulations lasted 54.5, 55, 58, 59, and 67 
minutes. The duration of a sixth copulation was less than 53 
minutes. Copulating pairs were generally quiescent, showing little 
antennal activity for most of the copulation period unless disturbed 
