Exposure to male pheromones enhances Anastrepha suspensa (Diptera : Tephritidae) female response to male calling song

Anastrepha suspensa (Loew) females are attracted to traps baited with male pheromone and/or broadcast calling song, but a high variability in female r esponsiveness has hindered attempts to use such attractants in practical tr apping systems. Prior experience is one factor that may contribute to varia bility in female responses. To investigate this possibility, female respons es to male calling song were compared after 38-40-h prior exposure to diffe rent combinations of live males, live females, synthetic pheromone componen ts, and broadcast song. The broadcast song, obtained from a sexually succes sful male, contained a series of wing-fanning pulse trains averaging 0.31-s in duration, separated by 0.36-s quiet intervals. Within the pulse trains, the frequency rose quickly from similar to 125 to 148 Hz and then slowly d eclined to similar to 120 Hz. The proportions of females responding to the broadcast calling song were greatest when females were first exposed to liv e males or pheromone components. These proportions significantly exceeded 0 % difference between the proportions under silent and broadcasting speakers . The proportion of females that responded after prior exposure to broadcas t song alone was significantly higher than the proportion that responded af ter no prior exposure to sexual stimuli, but it did not significantly excee d 0%.