1979] 
O’Neill — Behavior of Philanthus psyche 
35 
different (* 2 = 89.8; 8 d.f.; p < 0.001). Thus, there may be an 
optimal wind velocity range above and below which the males scent 
mark less often. Indeed, for the above males, 76% of all abdomen 
draggings were done at wind velocities between 41 and 100 m/min¬ 
ute, while only 31.8% of the overall wind velocity readings were in 
this range (N - 287). A general conclusion might be made that males 
do not scent mark randomly with respect to the wind, but in some 
manner (possibly during the weaving flight) cue to the wind velocity 
and adjust their marking behavior accordingly. In fact, detection of 
wind velocity during weaving flight may be its function alternative 
or simultaneous to monitoring airborne pheromone concentration. 
Sower et al. (1973) have shown that for a species which releases a 
sex pheromone in discrete pulses, there are both upper and lower 
limits to wind velocity between which communication is feasible. 
