Fig. 1. Examples of the range of variability in walking tracks of P. americana males tracking responses to (Ai–iii) continuous windborne plumes of female pheromone, (Bi–iii) loss of directional wind while tracking a plume, and (Ci–iii) loss of the pheromone plume while tracking it in wind in Series 1 experiments. The first panel (i) shows a response with the fewest turns, the second panel (ii) an example of a typical number of turns, and the last panel (iii) the responses with the largest number of turns. Continuous lines represent tracking while wind and pheromone were both present. Dotted lines represent behavior after the loss of wind or pheromone. Black circle at right side of plots represents the point of release of the cockroaches. Note that the first position was digitized when we could clearly resolve the cockroach and its walking path. When present, wind direction was from left to right and the pheromone source was on the left-hand edge of the arena (the arena is depicted by the black boxes in which the tracks are plotted).