@article {57637, title = {Sexual dimorphism in auditory mechanics: tympanal vibrations of Cicada orni}, year = {2008}, abstract = {

In cicadas, the tympanum is anatomically intricate and employs complex vibrations as a mechanism for auditory frequency analysis. Using microscanning laser Doppler vibrometry, the tympanal mechanics of Cicada orni can be characterized in controlled acoustical conditions. The tympanum of C. orni moves following a simple drum-like motion, rather than the travelling wave found in a previous study of Cicadatra atra. There is a clear sexual dimorphism in the tympanal mechanics. The large male tympanum is unexpectedly insensitive to the dominant frequency of its own calling song, possibly a reflection of its dual purpose as a sound emitter and receiver. The small female tympanum appears to be mechanically sensitive to the dominant frequency of the male calling song and to high-frequency sound, a capacity never suspected before in these insects. This sexual dimorphism probably results from a set of selective pressures acting in divergent directions, which are linked to the different role of the sexes in sound reception and production. These discoveries serve to indicate that there is far more to be learnt about the development of the cicada ear, its biomechanics and evolution, and the cicada\&$\#$39;s acoustic behaviour.

}, keywords = {biomechanics, hearing, high-frequency reception, laser vibrometry, predation, selective forces, tympanum}, doi = {10.1242/jeb.018804}, url = {http://jeb.biologists.org/cgi/doi/10.1242/jeb.018804https://syndication.highwire.org/content/doi/10.1242/jeb.018804}, author = {Sueur, J. and James F. C. Windmill and Robert, D.} } @article {57601, title = {Auditory Sensitivity of an Acoustic Parasitoid (Emblemasoma sp., Sarcophagidae, Diptera) and the Calling Behavior of Potential Hosts}, journal = {Brain, Behavior and Evolution}, volume = {72}, year = {2008}, month = {Jan-01-2008}, pages = {16 - 26}, abstract = {

Using field broadcasts of model male calling songs, we tested whether Tibicen pruinosa and T. chloromera (Homoptera: Cicadidae) are candidate hosts for acoustic parasitoid flies. The model calling song of T. pruinosa attracted 90\% of the flies (Sarcophagidae: Emblemasoma sp.; all larvapositing females) when broadcast simultaneously with the model T. chloromera song, a phonotactic bias reconfirmed in single song playbacks. In paired broadcasts of model T. pruinosa songs with different relative amplitudes (3 dB or 6 dB), significantly more flies were attracted to the more powerful song, a result consistent with the responses predicted by a model proposed by Forrest and Raspet [1994]. Using intracellular recordings and dye injections, we characterized the sensitivity of auditory units in sound-trapped flies. Intracellular recordings from six auditory units (5 interneurons, 1 afferent) revealed best sensitivity for frequencies near 3-4 kHz, matching the predominant spectral components of the calling songs of both species of cicada. Interestingly, although flies could be attracted to T. pruinosa broadcasts throughout the day, hourly censuses of singing males revealed that calling occurred exclusively at dusk. Furthermore, the duration of the dusk chorus in T. pruinosa was significantly shorter than the midday chorus of the less attractive song of T. chloromera. We propose that the tight temporal aggregation of the dusk chorus time could function to reduce risk from attracted parasitoids.

}, keywords = {Chorus, Cicada, cricket, Diel Behavior, Emblemasoma, frequency tuning, interneuron, Ormia, parasitoid, phonotaxis, Tibicen}, issn = {0006-8977}, doi = {10.1159/000139458}, url = {https://www.karger.com/Article/FullText/139458}, author = {Farris, H.E. and Oshinsky, M.L. and Forrest, T.G. and Ronald R. Hoy} }