1979] 
O’Neill — Behavior of Philanthus psyche 
37 
perched on the territory the males spend time grooming, particular 
attention paid to the mandibular area and the venter of the 
abdomen. 
Mating 
Three matings were seen in the nesting area and none elsewhere, 
wo of these were observed already in progress, the male and female 
coupled on a stem in the territorial area. The third copulation was 
initiated when a female flew upwind (orienting to pheromone?) and 
landed on the edge of a territory. The resident male immediately 
pounced upon her. They coupled at once and flew to a plant about 1 
m away where they remained still for about 4 minutes. At this point 
and again several minutes later, a second male landed on the back of 
the female resulting in the original pair changing perches once. They 
finally uncoupled after 8 minutes and 30 seconds. It was common to 
see females flying upwind through the territorial area in a low zig¬ 
zag flight. 6 
Discussion 
The mating strategy that males of a particular species adopt 
during the course of evolution can be evaluated in terms of 
probabilities. The optimal strategy is one which most often places 
the male in the right place at the right time to intercept or attract a 
sexually receptive female. The nature of this strategy is influenced 
by the habits of the females, the degree of competition with other 
males, the physiological limitations of the species, predation risks 
and other factors (Brown 1964, Alcock et al. 1978). Exact proba¬ 
bilities associated with a given mating strategy may be extremely 
difficult to obtain, especially when matings are rarely observed 
and when females presumably mate only once in their lifetime. 
However, relative probabilities may be obtained by studying the 
daily and seasonal activities of males and females. A compara¬ 
tive approach, utilizing the ecological and ethological character¬ 
istics of closely related species may also help in understanding 
the factors determining the optimal mating strategy. 
Males of Philanthus psyche are territorial in an area where 
potential mates are most likely to occur, that is, the nesting area. 
here are four other rendezvous places at which copulation is 
known to occur in the Sphecidae (Alcock et al. 1978). These are- 
the hunting area, flowers (nectar sites), landmark flyways and the 
