03010nas a2200181 4500008004100000245009100041210006900132520234200201653002902543653001202572653002402584653004202608653003302650653002302683100002202706700001902728856008102747 2013 eng d00aDiversity of acoustic tracheal system and its role for directional hearing in crickets0 aDiversity of acoustic tracheal system and its role for direction3 a

Background: Sound localization in small insects can be a challenging task due to physical constraints in deriving sufficiently large interaural intensity differences (IIDs) between both ears. In crickets, sound source localization is achieved by a complex type of pressure difference receiver consisting of four potential sound inputs. Sound acts on the external side of two tympana but additionally reaches the internal tympanal surface via two external sound entrances. Conduction of internal sound is realized by the anatomical arrangement of connecting trachea. A key structure is a trachea coupling both ears which is characterized by an enlarged part in its midline (i.e., the acoustic vesicle) accompanied with a thin membrane (septum). This facilitates directional sensitivity despite an unfavorable relationship between wavelength of sound and body size. Here we studied the morphological differences of the acoustic tracheal system in 40 cricket species (Gryllidae, Mogoplistidae) and species of outgroup taxa (Gryllotalpidae, Rhaphidophoridae, Gryllacrididae) of the suborder Ensifera comprising hearing and non hearing species.

Results: We found a surprisingly high variation of acoustic tracheal systems and almost all investigated species using intraspecific acoustic communication were characterized by an acoustic vesicle associated with a medial septum. The relative size of the acoustic vesicle - a structure most crucial for deriving high IIDs - implies an important role for sound localization. Most remarkable in this respect was the size difference of the acoustic vesicle between species; those with a more unfavorable ratio of body size to sound wavelength tend to exhibit a larger acoustic vesicle. On the other hand, secondary loss of acoustic signaling was nearly exclusively associated with the absence of both acoustic vesicle and septum.

Conclusion: The high diversity of acoustic tracheal morphology observed between species might reflect different steps in the evolution of the pressure difference receiver; with a precursor structure already present in ancestral non-hearing species. In addition, morphological transitions of the acoustic vesicle suggest a possible adaptive role for the generation of binaural directional cues.

10aAcoustic tracheal system10acricket10adirectional hearing10aInteraural intensity difference (IID)10aPressure difference receiver10aSound localization1 aSchmidt, Arne, KD1 aRömer, Heiner uhttp://frontiersinzoology.biomedcentral.com/articles/10.1186/1742-9994-10-6101238nas a2200121 4500008004100000245006600041210006600107520081600173100003100989700002301020700002501043856004801068 1983 eng d00aTympanal membrane motion is necessary for hearing in crickets0 aTympanal membrane motion is necessary for hearing in crickets3 a

1. Sound guided through the tracheal tube to the internal tracheal spaces in the region of the cricket ear is capable of eliciting auditory neural responses in the prothoracic ganglion if the tympanal membrane is allowed to vibrate freely. If the tympanal membrane motion is prevented mechanically neural responses are abolished (Fig. 3) whereas the sound pressure in the tracheal air spaces behind the tympanum is increased.

2. If the motion of the tympanum, as measured with laser vibrometry, is prevented by adjusting the internal and external sound pressure, then neural responses cease simultaneously (Fig. 5).

3. These findings demonstrate that motion of the large tympanum is a necessary requisite in the sound transduction process of the cricket ear.

1 aKleindienst, Hans, -Ulrich1 aWohlers, David, W.1 aLarsen, Ole, Næsbye uhttp://link.springer.com/10.1007/BF0060545502531nas a2200133 4500008004100000245007900041210006900120520206600189100002902255700002302284700001902307700001802326856005302344 2008 eng d00aMatched Filters, Mate Choice and the Evolution of Sexually Selected Traits0 aMatched Filters Mate Choice and the Evolution of Sexually Select3 a

Background: Fundamental for understanding the evolution of communication systems is both the variation in a signal and how this affects the behavior of receivers, as well as variation in preference functions of receivers, and how this affects the variability of the signal. However, individual differences in female preference functions and their proximate causation have rarely been studied.

Methodology/Principal Findings: Calling songs of male field crickets represent secondary sexual characters and are subject to sexual selection by female choice. Following predictions from the ‘‘matched filter hypothesis’’ we studied the tuning of an identified interneuron in a field cricket, known for its function in phonotaxis, and correlated this with the preference of the same females in two-choice trials. Females vary in their neuronal frequency tuning, which strongly predicts the preference in a choice situation between two songs differing in carrier frequency. A second ‘‘matched filter’’ exists in directional hearing, where reliable cues for sound localization occur only in a narrow frequency range. There is a strong correlation between the directional tuning and the behavioural preference in no-choice tests. This second ‘‘matched filter’’ also varies widely in females, and surprisingly, differs on average by 400 Hz from the neuronal frequency tuning.

Conclusions/Significance: Our findings on the mismatch of the two ‘‘matched filters’’ would suggest that the difference in these two filters appears to be caused by their evolutionary history, and the different trade-offs which exist between sound emission, transmission and detection, as well as directional hearing under specific ecological settings. The mismatched filter situation may ultimately explain the maintenance of considerable variation in the carrier frequency of the male signal despite stabilizing selection.

1 aKostarakos, Konstantinos1 aHartbauer, Manfred1 aRömer, Heiner1 aTregenza, Tom uhttps://dx.plos.org/10.1371/journal.pone.000300500351nas a2200109 4500008004100000245006200041210006200103300001200165490000700177100001600184856004100200 1982 eng d00aAcoustic communication and baffling behaviors of crickets0 aAcoustic communication and baffling behaviors of crickets a33–440 v651 aForrest, TG uhttps://bio.acousti.ca/fr/node/5314204414nas a2200145 4500008004100000022001400041245007000055210007000125260001600195300001400211490000700225520397000232100001804202856004804220 1971 eng d a0340-759400aBiophysik der Schallerzeugung durch die Vorderflügel der Grillen0 aBiophysik der Schallerzeugung durch die Vorderflügel der Grillen cJan-01-1971 a272 - 3140 v743 a

In several cricket species (Gryllus campestris L., Gryllus bimaculatus de Geer, and Acheta domesticus L.) the sound-radiating parts of the tegmen have been determined for the calling song. The oscillatory properties of these structures have been analysed.

1.
Extirpation of one harp-area (Fig. 2) lowered the sound pressure level of the first maximum (4–5 kHz) in the sound frequency spectrogram by 18 dB on the average (Fig. 4). This drop was partially reversed by installation of plastic substitutes (Fig. 5).

2.
The radiated sound can be changed by excising teeth on the pars stridens. By this means the damping characteristics of the tegminal resonator were calculated. The logarithmic decrements were between 0.086 and 0.262, depending on the animal.

3.
The sound level distribution on the surface of the tegmen of stridulating males was measured for the 5 kHz-component of the calling song. The fact that a distinct maximum of sound pressure was located on the harp (Fig. 7) demonstrates the sound-radiating function of this structure.

4.
The sound distribution around stridulating animals was measured in the equatorial and median planes (Fig. 8). The sound-radiation is directed. Microphone probe measurements in the 12 mm long cavity under the elevated tegmina showed a caudad directed sound-level-gradient of 9.3 dB on the average.

5.
The cavity under the tegmina has no resonator properties.

6.
The resonance frequency of the harp was calculated to be 5.6 kHz. This value corresponds closely to the measured resonance frequency of the harp, which varies with different specimens of Gryllus campestris from 4.2–5.4 kHz.

7.
Motion pictures of the wing covered with cork powder and excited with sound showed in a direct way the resonator properties of the harp and the mirror (Fig. 9).

8.
The resonance curve of the harp was determined (Fig. 10), and it was shown that the harp is a uniform and linear resonance system (Figs. 11 and 12). The harp frame has no resonator function (Fig. 13).

9.
The amplitude of the harp displacement in response to a sound pulse is an exponential function for the building-up-transient as well as for the dying-out-transient (Figs. 14 and 15).—From the resonance curve and the dying-out-transient the expected phaseshift between the driving force and the resonator displacement can be calculated. Calculated and experimentally determined values for the phase-shift are in good agreement (Fig. 17).

10.
Characteristics of the harp resonator (Q-factor, resonance frequency, response-threshold) were determined. The resonators of the right and left tegmen are differently tuned.

There is a close correlation between the resonance frequency of the harp and the location of the first maximum in the sound frequency spectrogram of the calling song (Table 3).

11.
In comparison with the pressure level of the radiated sound, the response threshold of the harp is rather low. For this reason a stridulating cricket can throw the harp of another animal into resonance (Fig. 18). This has been shown experimentally over distances up to 150 cm.

12.
The harp was artificially damped with a mass and the displacement of the resonance frequency was determined (Fig. 19). From this displacement the mass of the harp was calculated.

13.
In comparison with the harp the mirror is more strongly damped and it is tuned to a higher frequency of 7.2 kHz (Fig. 20 and Table 2).

14.
The tegminal resonators (harp and mirror) of Gryllus bimaculatus and Acheta domesticus (Fig. 21 and Table 2) are comparable to those of Gryllus campestris which have been studied in detail.

1 aNocke, Harald uhttp://link.springer.com/10.1007/BF0029773001621nas a2200181 4500008004100000245009300041210006900134300001000203490000800213520106600221653001701287653001301304653001601317653001601333100002701349700002201376856004101398 2008 eng d00aBioacoustic studies on some cricket species (Insecta:Orthoptera: Gryllidae) from Romania0 aBioacoustic studies on some cricket species InsectaOrthoptera Gr a57-640 vLIV3 a

There are 9 cricket species known from Romania belonging to the family Gryllidae. The ordinary stridulation of 7 species of those has been analyzed in this paper. The species belonging to the subfamily Gryllinae: Gryllus campestris, Acheta domestica, Melanogryllus desertus, Modicogryllus frontalis and Modicogryllus truncatus stridulate especially in the afternoon and in the evening, rarely during daytime, meanwhile the species Pteronemobius heydenii from the subfamily Nemobiinae stridulate only during daytime and especially by sunny weather, while the only species belonging to the subfamily Oecanthinae from our country fauna, Oecanthus pellucens, stridulate at night, very rarely during daytime (mostly in autumn). Details of the stridulatory vein and identification criteria for the studied cricket species are presented in this paper; also we have annalysed the spectrograms and the oscillograms for the ordinary stridulation of the 7 species. The species Modicogryllus truncatus, collected at Mărăşeşti, is a new report for Moldavia.

10abioacoustics10acrickets10aoscillogram10aspectrogram1 aIorgu, Ionuț, Ștefan1 aMustata, Gheorghe uhttps://bio.acousti.ca/fr/node/4779202044nas a2200229 4500008004100000022001300041245010800054210006900162260001600231300001400247490000700261520134900268653002501617653001201642653001701654653001001671653001401681100001901695700001801714700001701732856006501749 1984 eng d a0022191000aProcessing of vibratory and acoustic signals by ventral cord neurones in the cricket Gryllus campestris0 aProcessing of vibratory and acoustic signals by ventral cord neu cJan-01-1984 a575 - 5850 v303 a

The responses of single vibratory receptors and ascending ventral cord interneurones were studied extracellularly in Gryllus campestris L. The physiology of the vibration receptors resembled those found in tettigoniids and locusts. The frequency responses of the subgenual receptors provide two possible cues for central frequency discrimination: differences in mean tuning between groups of receptors in the different leg pairs and a range of receptors tuned to different frequencies within one subgenual organ.

Most of the ascending vibratory interneurones were highly sensitive in either the low or high frequency range. Broadbanded neurones were less sensitive. The characteristic sensitivity peaks of these units are due mainly to receptor inputs from a particular leg pair, although most central neurones receive inputs from all 6 legs. Only one neurone type, TN1 received excitatory inputs from both auditory and vibratory receptors; its responses were greatly enhanced by the simultaneous presentation of both stimulus modes. The responses to sound stimuli of AN2, on the other hand, were inhibited by vibration. No other auditory interneurones investigated were influenced by inputs from vibration receptors. Central processing of vibratory information in the cricket is compared with that of tettigoniids and locusts.

10acentral coprocessing10acricket10ainterneurone10asound10avibration1 aKühne, Roland1 aSilver, Susan1 aLewis, Brian uhttp://linkinghub.elsevier.com/retrieve/pii/002219108490086602330nas a2200229 4500008004100000022001400041245008500055210006900140260001300209300001100222490000700233520169200240653001201932653002201944653001201966653001201978653002701990653001002017100001802027700001402045856004102059 1966 eng d a0022-094900aThe neuromuscular mechanism of stridulation in crickets (Orthoptera: Gryllidae).0 aneuromuscular mechanism of stridulation in crickets Orthoptera G c1966 Aug a151-640 v453 a

Study of the insect neuromuscular system appears very promising as a means of
explaining behaviour in terms of cellular operation. The relatively small number of
neurons, the ganglionic nature of the nervous system, the simplicity of the neuro-
muscular arrangement, and the repetitiveness of behavioural sequences all lend them-
selves to a solution of this problem. As a result, an increasing number of investigators
have been turning their attention to insects and especially to the large orthopterans.
Recently, Ewing & Hoyle (1965) and Huber (1965) reported on muscle activity
underlying sound production in crickets. The acoustic behaviour is well understood
(Alexander, 1961) and in the genera Gryllus, Acheta and Gryllodes communication is
mediated by three basic songs composed of three types of pulses. While working
independently on this system at the University of Cologne (W.K.) and the University
of Michigan (D.B.) using various Gryllus species, we found a number of basic
differences between the muscle activity in our crickets and that reported by Ewing
& Hoyle (1965) for Acheta domesticus. These two genera, Gryllus and Acheta, are so
nearly identical that they are distinguished solely by differences in the male genitalia
(Chopard, 1961). The present paper constitutes a survey of muscle activity patterns
producing stridulation in four species of field crickets. Since the work of the two
authors was carried out independently, non-overlapping experiments will be initialled
to indicate the investigator.

10aAnimals10aElectrophysiology10ainsects10amuscles10aneuromuscular junction10asound1 aBentley, D, R1 aKutsch, W uhttps://bio.acousti.ca/fr/node/17213