02009nas a2200157 4500008004100000022001400041245008700055210006900142260001600211300001400227490000800241520151700249100002001766700001701786856004801803 1978 eng d a0340-759400aFunctional development of the auditory system of the cricket,Teleogryllus commodus0 aFunctional development of the auditory system of the cricketTele cJan-06-1978 a131 - 1380 v1273 a

1. In Teleogryllus commodus and T . oceanicus, vibration of the tibia of the prothoracic leg at audio-frequencies stimulates auditory receptors in the tympanal organ, despite immobilization of the large tympanum by vaseline.

2.Responses of characteristic auditory interneurons in the adult cervical connective are similar whether stimulation is by sound or by vibration of the tibia (Figs. 3–5).

3.Interneurons in second-last (A-2) and last (A-1) immature instars are stimulated by sound and by vibration of the tibia and we conclude that these interneurons are the same as those recorded in adults (Figs. 6, 7). Peripheral receptors and some interneurons in the immature auditory system are, therefore, physiologically competent.

4.At the imaginai moult, auditory threshold at the optimum frequency decreases dramatically (Fig. 8 A). This increase in sensitivity to sound is attributed mainly to the appearance of the auditory tympanum in the adult. There is a much smaller increase in sensitivity to vibration of the tibia at audio frequencies between last instar nymphs and adults (Fig. 8 B).

5.From the A-2 to adult stages of T. commodus, auditory receptors stimulated by sound show a peak sensitivity at 3.8 to 4.0 kHz (Fig. 8 A). Such tuning must be independent of vibration characteristics of the tympanum and of acoustic resonance characteristics depending on the dimensions of the leg trachea.

1 aBall, Eldon, E.1 aHill, K., G. uhttp://link.springer.com/10.1007/BF0135229702185nas a2200217 4500008004100000022001400041245011600055210006900171260001300240300001000253490000700263520154400270653001201814653001401826653001501840653001501855653001501870100002001885700001601905856004601921 1978 eng d a0022-075200aUltrastructural study of the development of the auditory tympana in the cricket Teleogryllus commodus (Walker).0 aUltrastructural study of the development of the auditory tympana c1978 Aug a75-870 v463 a

The cuticle in the tympanal area of immature crickets, Teleogryllus commodus (Walker), is ultrastructurally indistinguishable from that elsewhere on the prothoracic leg. It is only in the pharate adult that changes associated with development of the tympana first appear. In pharate adults and adults the external layer of the tympana consists of a layer of electron-dense material overlying a layer where the electron-dense material is interspersed with cuticle in which the bundles of microfibrils are coarser and more loosely arranged than elsewhere in the leg. The innermost portion of the tympana consists of this same type of cuticle without the electron-dense material. Associated with the appearance of the electron-dense material in the tympana of the pharate adult is a change in the toluidine blue staining properties from blue to deep purple. The reaction of the tympana in acid and base is consistent with their being composed of chitin. There are no major deposits of resilin in the tympana. In the first few days following the imaginal ecdysis the posterior tympanum and underlying trachea come into tight apposition due to the withdrawal of the epidermal cells. The epidermal cells do not withdraw from beneath the anterior tympanum. The surrounding non-tympanal cuticle continues to thicken for several weeks with the result that in the mature adult the posterior tympanum serves as an acoustic window in the thick cuticle of the leg. The functional significance of the anterior tympanum has not been established.

10aAnimals10aepidermis10amicrovilli10amiddle ear10aOrthoptera1 aBall, Eldon, E.1 aCowan, A, N uhttps://bio.acousti.ca/zh-hant/node/17205