Wing resonances in the Australian field cricket Teleogryllus oceanicus
Wing resonances in the Australian field cricket Teleogryllus oceanicus
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DOI：
10.1242/jeb.00281
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发表时间：
2003-05-01
影响因子：
2.8
通讯作者：
Bennet-Clark, HC
中科院分区：
文献类型：
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作者：
Bennet-Clark, HC
为了研究澳大利亚蟋蟀Teleogryllus oceanicus前翅的共振激发方式、发声过程中两翅之间的相互作用、脉冲频率的变化以及脉冲过程中声幅的变化，对前翅的解剖学和力学进行了研究。左翼的拨片接合和释放右翼下侧的锉刀上的齿。右锉的平均齿数为252;在锉的后部，齿的间距更近，这是在歌曲脉冲开始时啮合的。锉的前部通过一个短的柔性区域与竖琴的基部分开。竖琴所在的翅膀背侧区域，除了竖琴顶端的横脉外，在很大程度上与侧区域的驱动静脉机械隔离。两个翅膀的竖琴在面积上没有显着差异，但左翅膀的琴拨明显长于右翅膀的琴拨。拨片的后边缘具有大约0.5 μ m的半径，这允许拨片接合锉的20 μ m高的齿。琴拨与翅膀之间有一个0.5 μ m厚的新月，可以纵向扭转，从而使锉齿脱离。锉的S形形状允许拨片在锉的大部分长度上与牙齿啮合。oceanicus由四个类似脉冲的啁啾和随后的成对脉冲的颤音组成。所有脉冲的主频率约为4.8 kHz，但逐周期分析表明，不同类型的脉冲是由通过不同弧线的翅膀闭合运动产生的。左翼的自由共振频率为4.56 kHz [品质因数（Q）=25.1]，右翼的自由共振频率为4.21 kHz（Q=23.9）。在响亮的声音驱动下，竖琴的最大振动出现在约4.5 kHz处;在较低的声级下，振动仅限于从锉向远端延伸的竖琴的横脉。左翼的共振由同一个翅膀的振动驱动，无论是在拨片还是在肛门区域，都发生在与歌曲相似的频率上，并且具有相似的Q，但近似反相，这表明拨片的运动（例如通过锉齿）导致竖琴的相反运动。当右翼直接在锉刀上驱动时，共振频率为5.88 kHz，但是当通过左锉刀和左拨片的长度在锉刀上驱动时，共振频率为4.83 kHz。振动的幅度从锉的后端到中部逐渐增大，然后向锉的前端下降。将左拨片推过右锉的中间产生4.82 kHz（Q=23.4）的阻尼声脉冲串。从锉前端激发的点击频率较低。从左翼通过它的拨片和右翼时，通过左拨片驱动激发的共振频率相似的song.The共振的背场持续消融后的竖琴，但平均共振频率增加了1.12倍，类似的Q完整的翅膀。在竖琴的远端或背场的近端部分上的水滴提高了共振频率。通过在竖琴或锉刀上增加重量，共振频率降低;降低的因素表明共振系统的质量约为1.4 mg，这与竖琴加锉刀加机翼肛门面积的质量（左翼，1.27 mg;右翼，1.15 mg）一致，但远比竖琴重（0.22 mg）。早期的竖琴是共鸣器的建议不被支持;相反，它提出了共振系统的主要弹性组件是文件加上第一肛门静脉，质量组件是文件，肛门区域和竖琴的组合质量。
The anatomy and mechanics of the fore-wings of the Australian cricket Teleogryllus oceanicus were examined to study how resonances of the wings were excited, to model the interactions between the two wings during sound production, to account for the frequency changes that occur within the pulses and to determine the variation in sound amplitude during the pulses.Sound is produced after raising the wings by closing the right wing over the left; the plectrum of the left wing engages and releases teeth on the file on the underside of the right wing. The mean number of teeth on the right file is 252; the teeth are more closely spaced in the posterior part of the file, which is engaged at the start of the song pulses. The anterior part of the file is separated from the base of the harp by a short flexible region. The dorsal field of the wing, in which the harp is situated, is largely mechanically isolated from the driving veins of the lateral field, except for a cross vein at the apex of the harp. The harps of the two wings did not differ significantly in area but the plectrum of the left wing was significantly longer and wider than that of the right wing. The posterior edge of the plectrum has a radius of approximately 0.5 mum, which allows it to engage the 20 mum-tall teeth of the file. The plectrum is separated from the wing by a 0.5 mum-thick crescent that allows it to twist lengthways and thus disengage the file teeth. The sigmoid shape of the file allows the plectrum to engage teeth over most of the length of the file.The calling song of T. oceanicus consists of a chirp of four similar pulses followed by a trill of pairs of pulses. The dominant frequency of all pulses is approximately 4.8 kHz but cycle-by-cycle analysis suggests that the different types of pulse are produced by wing-closing movements through different arcs. Free resonances of the left wing occurred at 4.56 kHz [quality factor (Q)=25.1] and of the right wing at 4.21 kHz (Q=23.9). Driven by loud sound, maximum vibration of the harp was seen at approximately 4.5 kHz; at lower sound levels, the vibration was confined to the cross-veins of the harp that extend distally from the file. Resonances of the left wing driven by vibration of the same wing, either at the plectrum or on the anal area, occurred at similar frequencies to those of the songs and had similar Qs but were approximately anti-phase, demonstrating that movement of the plectrum (e.g. by the file teeth) causes an opposite movement of the harp. When the right wing was driven directly on the file, the resonant frequency was 5.88 kHz but, when driven on the file via a length of the left file and the left plectrum, it was 4.83 kHz. The amplitude of the vibration increased from the posterior end of the file to the middle then fell towards the anterior end of the file. Pushing a left plectrum across the middle of the right file produced trains of damped sound pulses at 4.82 kHz (Q=23.4). Clicks excited from the anterior end of the file had lower frequencies. The resonances excited from both the left wing via its plectrum and from the right wing when driven via the left plectrum were similar in frequency to that of the song.The resonance of the dorsal field persisted after ablation of the harp but the mean resonant frequency increased 1.12-fold with a similar Q to the intact wing. Droplets of water on the distal end of the harp or proximal part of the dorsal field raised the resonant frequency. The resonant frequency was lowered by the addition of weights to the harp or the file; the factor of the decrease suggested that the mass of the resonant system was approximately 1.4 mg, which accords with the mass of the harp plus file plus anal area of the wing (left wing, 1.27 mg; right wing, 1.15 mg) but is far heavier than the harp (0.22 mg). An earlier suggestion that the harp is the resonator is not supported; instead, it is proposed that the major elastic component of the resonant system is the file plus 1st anal vein and that the mass component is the combined mass of the file, anal area and harp.