Figure 1

Hearing threshold and phonotactic behaviour of E. auditrix . A The hearing threshold of E. auditrix is depicted as a solid black line (modified after [8]). The calling song spectra have been analyzed by Fast Fourier Transformation: host cicada O. rimosa (dotted red line), periodical cicadas M. cassinii and M. septendecim (stippeld green and blue lines). Note the overlap of hearing range with the spectrum of M. cassinii, whereas M. septendecim can hardly be detected acoustically. B Phonotaxis of E. auditrix in behavioural tests in the laboratory (columns; left y-axis) and in attraction experiments in the field (black squares; mean, s.e.m.; right axis). In the laboratory arena phonotaxis was tested towards calling songs (80 dB SPL at 50 cm); the arrival at the loudspeaker is plotted as percentage of the number of animals (22 replicates for each song). In the field, flies were counted which arrived at the loudspeaker during a three minute broadcast of the respective song model (100 dB SPL at 1 m distance) (5 replicates for each model).