Individual male cabbage looper moths, Trichoplusia ni, were tested in a sustained-flight tunnel to the sex pheromone, a 93:7 blend of (Z)-7-dodecenyl acetate and dodecyl acetate. Two experimental procedures were used to investigate the interaction of the two components in the upwind flight response of males. In the first test, chemical components were selectively removed from the moths' flight path at two distances from the source, corresponding to areas of the tunnel in which the blend was or was not active in increasing the number of upwind flights. In the second test, males were offered a choice between plumes, in their normal flight path, which contained different components. Results of both tests showed that males were unresponsive to dodecyl acetate alone at all phases of the flight response, responses to the blend were dependent on the two components being mixed in the same plume, and response to the blend altered the males subsequent flight response to Z7-12:Ac alon
