02297nas a2200157 4500008004100000245013200041210006900173520170500242100001801947700002001965700002101985700002102006700001802027700002702045856006702072 1998 eng d00aStimulus transmission in the auditory receptor organs of the foreleg of bushcrickets (Tettigoniidae) I. The role of the tympana0 aStimulus transmission in the auditory receptor organs of the for3 a

The auditory organs of the tettigoniid are located just below the femoral tibial joint in the forelegs. Structurally each auditory organ consists of a tonotopically organized crista acustica and intermediate organ and associated sound conducting structures; an acoustic trachea and two lateral tympanic membranes located at the level of the receptor complex. The receptor cells and associated satellite structures are located in a channel filled with hemolymph fluid. The vibratory response characteristics of the tympanic membranes generated by sound stimulation over the frequency range 2–40 kHz have been studied using laser vibrometry. The acoustic trachea was found to be the principal structure through which sound energy reached the tympana. The velocity of propagation down the trachea was observed to be independent of the frequency and appreciably lower than the velocity of sound in free space. Structurally the tympana are found to be partially in contact with the air in the trachea and with the hemolymph in the channel containing the receptor cells. The two tympana were found to oscillate in phase, with a broad band frequency response, have linear coherent response characteristics and small time constant. Higher modes of vibration were not observed. Measurements of the pattern of vibration of the tympana showed that these structures vibrate as hinged flaps rather than vibrating stretched membranes. These findings, together with the morphology of the organ and physiological data from the receptor cells, suggest the possibility of an impedance matching function for the tympana in the transmission of acoustic energy to the receptor cells in the tettigoniid ear.

1 aBangert, Marc1 aKalmring, Klaus1 aSickmann, Thomas1 aStephen, Richard1 aJatho, Martin1 aLakes-Harlan, Reinhard uhttps://linkinghub.elsevier.com/retrieve/pii/S037859559700177901757nas a2200121 4500008004100000245003800041210003800079300001000117490000800127520143900135100002001574856004101594 1981 eng d00aUltraljud hos svenska vårtbitare0 aUltraljud hos svenska vårtbitare a27-410 v1023 a

Of the 10 Swedish species of bush crickets 9 stridulate with their elytra. The author recorded the songs of these species in their natural habitats, using instrumentation tape recorder and ultrasonic detectors. Song rhythm patterms and frequencies are presented for each species with comments on the ultrasonic components, audibility as a distance in the field with and without detectors etc. For 8 of the 9 stridulating species detectors seem to be necessary for efficient survey work and population studies in the field.

In 5 species differences found between the songs used in daytime and at night were analysed and discussed. The most important differences were found in species singing close to the ground (Platycleis denticulata, Metrioptera brachyptera, M. bicolor), whereas no corresponding difference was found in species singing from trees or high busghes (Tettigonia viridissima, Leptophyes punctatissima). The very intense songs heard at night have distinct and discrete tooth-pulses, while corresponding songs in daytime contain continuous sound waves and less conspicuous tooth-pulses in the file pulse-train. It is suggested taht this phenomenon could be something more than a mere influence of temperature on song rhythym. They could be adaptations to more efficient spread of sound waves under the acoustical conditions taht prevail above ground at night.

1 aAhlén, Ingemar uhttps://bio.acousti.ca/it/node/17245