02141nas a2200157 4500008004100000022001300041245009300054210006900147260001600216300001600232490000700248520145600255100002001711700001901731856023301750 2013 eng d a0960982200aA Tympanal Insect Ear Exploits a Critical Oscillator for Active Amplification and Tuning0 aTympanal Insect Ear Exploits a Critical Oscillator for Active Am cJan-10-2013 a1952 - 19570 v233 a

A dominant theme of acoustic communication is the partitioning of acoustic space into exclusive, species-specific niches to enable efficient information transfer. In insects, acoustic niche partitioning is achieved through auditory frequency filtering, brought about by the mechanical properties of their ears [1]. The tuning of the antennal ears of mosquitoes [2] and flies [3], however, arises from active amplification, a process similar to that at work in the mammalian cochlea [4]. Yet, the presence of active amplification in the other type of insect ears—tympanal ears—has remained uncertain [5]. Here we demonstrate the presence of active amplification and adaptive tuning in the tympanal ear of a phylogenetically basal insect, a tree cricket. We also show that the tree cricket exploits critical oscillator-like mechanics, enabling high auditory sensitivity and tuning to conspecific songs. These findings imply that sophisticated auditory mechanisms may have appeared even earlier in the evolution of hearing and acoustic communication than currently appreciated. Our findings also raise the possibility that frequency discrimination and directional hearing in tympanal systems may rely on physiological nonlinearities, in addition to mechanical properties, effectively lifting some of the physical constraints placed on insects by their small size [6] and prompting an extensive reexamination of invertebrate audition.

1 aMhatre, Natasha1 aRobert, Daniel uhttps://linkinghub.elsevier.com/retrieve/pii/S0960982213010348https://api.elsevier.com/content/article/PII:S0960982213010348?httpAccept=text/xmlhttps://api.elsevier.com/content/article/PII:S0960982213010348?httpAccept=text/plain01615nas a2200145 4500008004100000245005200041210005200093260001900145520117200164100002001336700002801356700002501384700001901409856004101428 2012 eng d00aSound reception and radiation in a small insect0 aSound reception and radiation in a small insect aNantes, France3 a

Insects are small; this is a fact of their life. In some contexts this is an advantage, such as insects do not injure themselves through the effects of gravity. In other contexts this is a disadvantage, especially in the context of sound production and reception. The wavelengths of sound that insects such as crickets produce and receive are several times larger than their body size. For sound production, this is particularly challenging and inefficient, as sub-wavelength radiation (size to lambda ratio > 1:100) requires great energy expenditure to produce sufficient sound pressure. In receiving sound, they face the reciprocal problem and are inefficient receivers. In addition,  because of their size they cannot rely on cues other animals use to detect the direction of sound. Nonetheless, sound is extremely important to these insects as they use it for mate attraction and to evade predators. We investigate this problem by combining the technique of microscanning laser Doppler vibrometry with finite element modelling; and explain some of the biomechanical tricks a tiny tree cricket uses to overcome the disadvantages of size.

1 aMhatre, Natasha1 aMontealegre-Z, Fernando1 aBalakrishnan, Rohini1 aRobert, Daniel uhttps://bio.acousti.ca/ja/node/5799101733nas a2200169 4500008004100000022001400041245008900055210006900144260001600213300001600229490000800245520119600253100001801449700002601467700001901493856005101512 2010 eng d a0001-496600aSound emission and reception tuning in three cicada species sharing the same habitat0 aSound emission and reception tuning in three cicada species shar cJan-03-2010 a1681 - 16880 v1273 a

Many animal species acoustically communicate at the same place and time generating complex acoustic environments. However, the acoustic parameter space is usually structured, with each species emitting identifiable signals. While signal partitioning has been reported, very few analyses include the mechanical spectral response of auditory organs. The loud chorus generated by . The vibration pattern of L. plebejus shows traveling waves as previously observed in Ctra. atra. The spectral properties of both calling songs and tympanal auditory systems primarily indicate that each species uses its own frequency band.y, except for C. orni, which is sensitive to the lowest frequency band of its song. In contrast, female TMs are broadly tuned to the male songs. Ctra. atra females differ by tuning to frequencies slightly higher than the male song. Hence, acoustic space partitioning occurs for both emitter and receiver, but does not seem to fully preclude interference risk as some spectral overlap exists. In addition to the local physical ecology of each species, selective attention to conspecific signals is likely to be enhanced by further mechanical and neuronal processing.

1 aSueur, Jerome1 aWindmill, James, F.C.1 aRobert, Daniel uhttp://asa.scitation.org/doi/10.1121/1.329103601444nas a2200205 4500008004100000245006500041210006500106520072400171653002400895653002900919653001200948653002900960653001300989100001901002700002501021700002001046700002201066700001901088856013101107 2014 eng d00aEnergy localization and frequency analysis in the locust ear0 aEnergy localization and frequency analysis in the locust ear3 a

Animal ears are exquisitely adapted to capture sound energy and perform signal analysis. Studying the ear of the locust, we show how frequency signal analysis can be performed solely by using the structural features of the tympanum. Incident sound waves generate mechanical vibrational waves that travel across the tympanum. These waves shoal in a tsunami- like fashion, resulting in energy localization that focuses vibrations onto the mechanosensory neurons in a frequency-dependent manner. Using finite element analysis, we demonstrate that two mechanical properties of the locust tympanum, distributed thickness and tension, are necessary and sufficient to generate frequency-dependent energy localization.

10aenergy localization10afrequency discrimination10atension10atravelling flexural wave10atympanum1 aMalkin, Robert1 aMcDonagh, Thomas, R.1 aMhatre, Natasha1 aScott, Thomas, S.1 aRobert, Daniel uhttps://royalsocietypublishing.org/doi/10.1098/rsif.2013.0857https://royalsocietypublishing.org/doi/pdf/10.1098/rsif.2013.085702319nas a2200181 4500008004100000245008700041210006900128520167300197653002101870653001201891653001601903653001801919100001501937700002101952700001901973700002501992856012002017 2011 eng d00aMatching sender and receiver: poikilothermy and frequency tuning in a tree cricket0 aMatching sender and receiver poikilothermy and frequency tuning 3 a

Animals communicate in non-ideal and noisy conditions. The primary method they use to improve communication efficiency is sender-receiver matching: the receiver's sensory mechanism filters the impinging signal based on the expected signal. In the context of acoustic communication in crickets, such a match is made in the frequency domain. The males broadcast a mate attraction signal, the calling song, in a narrow frequency band centred on the carrier frequency (CF), and the females are most sensitive to sound close to this frequency. In tree crickets, however, the CF changes with temperature. The mechanisms used by female tree crickets to accommodate this change in CF were investigated at the behavioural and biomechanical level. At the behavioural level, female tree crickets were broadly tuned and responded equally to CFs produced within the naturally occurring range of temperatures (18 to 27°C). To allow such a broad response, however, the transduction mechanisms that convert sound into mechanical and then neural signals must also have a broad response. The tympana of the female tree crickets exhibited a frequency response that was even broader than suggested by the behaviour. Their tympana vibrate with equal amplitude to frequencies spanning nearly an order of magnitude. Such a flat frequency response is unusual in biological systems and cannot be modelled as a simple mechanical system. This feature of the tree cricket auditory system not only has interesting implications for mate choice and species isolation but may also prove exciting for bio-mimetic applications such as the design of miniature low frequency microphones.

10afrequency tuning10ahearing10aOecanthinae10atree crickets1 aMhatre, N.1 aBhattacharya, M.1 aRobert, Daniel1 aBalakrishnan, Rohini uhttp://jeb.biologists.org/cgi/doi/10.1242/jeb.057612https://syndication.highwire.org/content/doi/10.1242/jeb.05761202263nas a2200205 4500008004100000245006100041210006000102520159300162653001801755653002101773653002201794653002301816653000901839100001401848700002201862700001601884700001801900700001901918856012001937 2011 eng d00aMechanical filtering for narrow-band hearing in the weta0 aMechanical filtering for narrowband hearing in the weta3 a

This paper constitutes a major attempt to associate tympanic deflections with the mechanoreceptor organ location in an acoustic insect. The New Zealand tree weta (Hemideina thoracica) has tympanal ears located on each of the prothoracic tibiae. The tympana exhibit a sclerotized oval plate, membranous processes bulging out from the tibial cuticle and many loosely suspended ripples. We used microscanning laser Doppler vibrometry to determine how such a tympanal membrane vibrates in response to sound and whether the sclerotized region plays a role in hearing. The tympanum displays a single resonance at the calling frequency of the male, an unusual example of an insect tympana acting as a narrow bandpass filter. Both tympana resonate in phase with the stimulus and with each other. Histological sections show that the tympanal area is divided into two distinct regions, as in other ensiferans. An oval plate lies in the middle of a thickened region and is surrounded by a transparent and uniformly thin region. It is hinged dorsally to the tympanal rim and thus resembles the model of a ‘hinged flap’. The thickened region appears to act as a damping mass on the oscillation of the thin region, and vibration displacement is reduced in this area. The thinner area vibrates with higher amplitude, inducing mechanical pressure on the dorsal area adjacent to the crista acustica. We present a new model showing how the thickened region might confer a mechanical gain onto the activation of the crista acustica sensory neurons during the sound-induced oscillations.

10aensiferan ear10alaser vibrometry10amechanical tuning10atympanum vibration10aweta1 aLomas, K.1 aMontealegre-Z, F.1 aParsons, S.1 aField, L., H.1 aRobert, Daniel uhttp://jeb.biologists.org/cgi/doi/10.1242/jeb.050187https://syndication.highwire.org/content/doi/10.1242/jeb.05018703077nas a2200265 4500008004100000245012200041210006900163520220600232653001302438653001202451653002102463653002602484653001502510653001902525653001602544653001202560653001302572100001802585700001502603700001302618700001602631700002502647700001902672856012002691 2013 eng d00aLow-pass filters and differential tympanal tuning in a paleotropical bushcricket with an unusually low frequency call0 aLowpass filters and differential tympanal tuning in a paleotropi3 a

Low-frequency sounds are advantageous for long-range acoustic signal transmission, but for small animals they constitute a challenge for signal detection and localization. The efficient detection of sound in insects is enhanced by mechanical resonance either in the tracheal or tympanal system before subsequent neuronal amplification. Making small structures resonant at low sound frequencies poses challenges for insects and has not been adequately studied. Similarly, detecting the direction of long-wavelength sound using interaural signal amplitude and/or phase differences is difficult for small animals. Pseudophylline bushcrickets predominantly call at high, often ultrasonic frequencies, but a few paleotropical species use lower frequencies. We investigated the mechanical frequency tuning of the tympana of one such species, Onomarchus uninotatus, a large bushcricket that produces a narrow bandwidth call at an unusually low carrier frequency of 3.2 kHz. Onomarchus uninotatus, like most bushcrickets, has two large tympanal membranes on each fore-tibia. We found that both these membranes vibrate like hinged flaps anchored at the dorsal wall and do not show higher modes of vibration in the frequency range investigated (1.5–20 kHz). The anterior tympanal membrane acts as a low-pass filter, attenuating sounds at frequencies above 3.5 kHz, in contrast to the high-pass filter characteristic of other bushcricket tympana. Responses to higher frequencies are partitioned to the posterior tympanal membrane, which shows maximal sensitivity at several broad frequency ranges, peaking at 3.1, 7.4 and 14.4 kHz. This partitioning between the two tympanal membranes constitutes an unusual feature of peripheral auditory processing in insects. The complex tracheal shape of O. uninotatus also deviates from the known tube or horn shapes associated with simple band-pass or high-pass amplification of tracheal input to the tympana. Interestingly, while the anterior tympanal membrane shows directional sensitivity at conspecific call frequencies, the posterior tympanal membrane is not directional at conspecific frequencies and instead shows directionality at higher frequencies.

10aauditory10akatydid10alaser vibrometry10aOnomarchus uninotatus10aOrthoptera10apseudophylline10atettigoniid10atrachea10atympanum1 aRajaraman, K.1 aMhatre, N.1 aJain, M.1 aPostles, M.1 aBalakrishnan, Rohini1 aRobert, Daniel uhttp://jeb.biologists.org/cgi/doi/10.1242/jeb.078352https://syndication.highwire.org/content/doi/10.1242/jeb.07835201885nas a2200193 4500008004100000245009700041210006900138520127800207653001701485653001101502653002901513653001201542653002001554653001301574100001801587700002601605700001901631856004101650 2006 eng d00aTuning the drum: the mechanical basis for frequency discrimination in a Mediterranean cicada0 aTuning the drum the mechanical basis for frequency discriminatio3 a

Cicadas are known to use sound to find a mate. While the mechanism employed by male cicadas to generate loud calling songs has been described in detail, little information exists to explain how their ears work. Using microscanning laser Doppler vibrometry, the tympanal vibrations in the cicada Cicadatra atra are measured in response to acoustic playbacks. The topographically accurate optical measurements reveal the vibrational behaviour of the anatomically complex tympanal membrane. Notably, the tympanal ridge, a distinct structural element of the tympanum that is a link to the receptor cells, undergoes mechanical vibrations reminiscent of a travelling wave. In effect, the frequency for which the maximum deflection amplitude is observed regularly decreases from the apex to the base of the ridge. It is also shown that whilst female ears are mechanically tuned to the male's song, the male's tympanum is only partially tuned to its own song. This study establishes the presence of a peripheral auditory mechanism that can potentially process auditory frequency analysis. In view of the importance of acoustic signalling in cicadas, this unconventional tympanal mechanism may be employed in the context of species recognition and sexual selection.

10abiomechanics10aCicada10afrequency discrimination10ahearing10atravelling wave10atympanum1 aSueur, Jerome1 aWindmill, James, F.C.1 aRobert, Daniel uhttps://bio.acousti.ca/ja/node/5762200969nas a2200169 4500008004100000022001300041245004500054210004500099260001600144300001400160490000700174520032400181100002100505700002100526700001900547856023300566 2012 eng d a1360138500aTowards understanding plant bioacoustics0 aTowards understanding plant bioacoustics cJan-06-2012 a323 - 3250 v173 a

Little is known about plant bioacoustics. Here, we pres- ent a rationale as to why the perception of sound and vibrations is likely to have also evolved in plants. We then explain how current evidence contributes to the view that plants may indeed benefit from mechanosen- sory mechanisms thus far unsuspected.

1 aGagliano, Monica1 aMancuso, Stefano1 aRobert, Daniel uhttps://linkinghub.elsevier.com/retrieve/pii/S1360138512000544https://api.elsevier.com/content/article/PII:S1360138512000544?httpAccept=text/xmlhttps://api.elsevier.com/content/article/PII:S1360138512000544?httpAccept=text/plain01984nas a2200181 4500008004100000022001400041245008600055210006900141260001600210300001600226490000800242520141700250100001801667700002101685700001901706700002601725856005101751 2018 eng d a0001-496600aThe micromechanics and bioacoustic behaviour of Bunaea alcinoe moth scales0 amicromechanics and bioacoustic behaviour of iBunaea alcinoeI mot cJan-09-2018 a1775 - 17750 v1443 a

Through the 65 million year acoustic arms race between moths and bats, different moth species have evolved different defence strategies against bat echolocation. For non-toxic moth species without hearing capability, passive acoustic camouflage is thought to be the most efficient way to evade bat predation. Being the elementary building blocks covering moth wing surfaces, scales have been hypothesized as the main organ creating such acoustic camouflage. There is, however, no understanding for the relation between scale microstructure and wing acoustic performance. This report represents the first effort to numerically and experimentally characterize moth scale biomechanics and vibrational behaviour. 3D microstructures of Bunaea alcinoe moth scales have been characterized using various microscopies. A parameterized finite element model has been built to replicate the double-layered perforated scale bio-nanomaterial. Both experimental and numerical analyses have proved that the first three resonance frequencies of a single scale lie within the bat echolocation frequency range. Here, we propose numerical models that explain how the resonances can contribute to the acoustic performance of wings. This study contributes to the on-going discussion of the evolution of ultrasonic camouflage in moths. We aim to use our findings to generate biomimetic light-weight noise mitigation materials.

1 aShen, Zhiyuan1 aNeil, Thomas, R.1 aRobert, Daniel1 aDrinkwater, Bruce, W. uhttp://asa.scitation.org/doi/10.1121/1.506785201618nas a2200181 4500008004100000022001400041245005500055210005500110260001600165300001600181490000800197520109600205100002101301700001801322700002601340700001901366856005101385 2018 eng d a0001-496600aStealthy moths avoid bats with acoustic camouflage0 aStealthy moths avoid bats with acoustic camouflage cJan-09-2018 a1742 - 17420 v1443 a

Intense predation pressure from echolocating bats has led to the evolution of a host of anti-bat defences in nocturnal moths. Some have evolved ears to detect the ultrasonic biosonar of bats, yet there are many moths that are completely deaf. To enhance their survival chances, deaf moths must instead rely on passive defences. Here, we show that furry morphological specializations give moth bodies and wing joints acoustic stealth by reducing their echoes from bat calls. Using acoustic tomography, echo strength was quantified in the spatial and frequency domains of two deaf moth species that are subject to bat predation and two butterfly species that are not. Thoracic fur determines acoustic camouflage of moths but not butterflies. Thoracic fur provides substantial acoustic stealth at all ecologically relevant ultrasonic frequencies, with fur removal increasing a moth’s detection risk by as much as 38%. The thorax fur of moths acts as a lightweight porous sound absorber, facilitating acoustic camouflage and offering a significant survival advantage against bats.

1 aNeil, Thomas, R.1 aShen, Zhiyuan1 aDrinkwater, Bruce, W.1 aRobert, Daniel uhttp://asa.scitation.org/doi/10.1121/1.506772501293nas a2200169 4500008004100000022001400041245008500055210006900140260001600209300001600225490000800241520069000249100001900939700001500958700002000973856013000993 1992 eng d a0036-807500aThe evolutionary convergence of hearing in a parasitoid fly and its cricket host0 aevolutionary convergence of hearing in a parasitoid fly and its  cJan-11-1993 a1135 - 11370 v2583 a

Parasitism is a widespread and diverse life strategy that connects species throughout the animal kingdom. Female parasitoid flies of the genus Ormia must find a specific cricket host on which to deposit their parasitic maggots. To reproduce, female flies must perform the same task as female crickets: find a singing male cricket. These flies have evolved a unique hearing organ that allows them to detect and locate singing male crickets. Through evolutionary convergence, these flies possess a hearing organ that much more resembles a cricket's ear than a typical fly's ear, allowing these parasitoids to take advantage of the sensory ecological niche of their host.

1 aRobert, Daniel1 aAmoroso, J1 aHoy, Ronald, R. uhttp://www.sciencemag.org/cgi/doi/10.1126/science.1439820https://syndication.highwire.org/content/doi/10.1126/science.143982001924nas a2200157 4500008004100000022001300041245014500054210006900199260001600268300001400284490000700298520136100305100001601666700001901682856006501701 1995 eng d a0022191000aEffects of a tachinid parasitoid, Ormia ochracea, on the behaviour and reproduction of its male and female field cricket hosts (Gryllus spp)0 aEffects of a tachinid parasitoid Ormia ochracea on the behaviour cJan-03-1995 a269 - 2770 v413 a

The larvae of the tachinid parasitoid fly, Ormia ochracea, develop within the body of their host, the field crickets Gryllus integer and Gryllus rubens. The fly will also develop within the cricket Gryllus bimaculatus, which is not the natural host. For the first 3 days after entering a cricket, the first instar larvae grew inside the large thoracic muscles, but did little damage to the muscles during this time. They then migrated into the abdomen where they moulted, attached themselves to the body wall and fed primarily on the host's muscle and fat body, sparing the digestive system and CNS. Usually the host's reproductive system was only partially damaged. After the larvae entered the abdominal cavity, the host's mating, egg-laying and fighting ability (males) declined. This decline probably occurred due to the tissue damage wrought by the parasitoid. Less energy-demanding behaviours, such as grooming and feeding, were not affected during the entire period of infestation. During the first instar (when the parasitoid is embedded in the host's muscle), male crickets showed an increased tendency to attack other males. This increased incidence of agonistic behaviour occurred before the parasitoid caused significant tissue damage to the host and must therefore have been due to some other effect of the parasitoid.

1 aAdamo, S.A.1 aRobert, Daniel uhttp://linkinghub.elsevier.com/retrieve/pii/002219109400095X02082nas a2200229 4500008004100000022001400041245007400055210006900129260001600198300001600214490000700230520136400237653002301601653001601624653003101640653002001671100002901691700002501720700003301745700001901778856005501797 2011 eng d a0028-104200aTympanal mechanics and neural responses in the ears of a noctuid moth0 aTympanal mechanics and neural responses in the ears of a noctuid cJan-12-2011 a1057 - 10610 v983 a

Ears evolved in many groups of moths to detect the echolocation calls of predatory bats. Although the neurophysiology of bat detection has been intensively studied in moths for decades, the relationship between sound-induced movement of the noctuid tympanic membrane and action potentials in the auditory sensory cells (A1 and A2) has received little attention. Using laser Doppler vibrometry, we measured the velocity and displacement of the tympanum in response to pure tone pulses for moths that were intact or prepared for neural recording. When recording from the auditory nerve, the displacement of the tympanum at the neural threshold remained constant across frequencies, whereas velocity varied with frequency. This suggests that the key biophysical parameter for triggering action potentials in the sensory cells of noctuid moths is tympanum displacement, not velocity. The validity of studies on the neurophysiology of moth hearing rests on the assumption that the dissection and recording procedures do not affect the biomechanics of the ear. There were no consistent differences in tympanal velocity or displacement when moths were intact or prepared for neural recordings for sound levels close to neural threshold, indicating that this and other neurophysiological studies provide good estimates of what intact moths hear at threshold.

10aauditory threshold10aLepidoptera10amoth auditory biomechanics10aneurophysiology1 aHofstede, Hannah, M. ter1 aGoerlitz, Holger, R.1 aMontealegre-Zapata, Fernando1 aRobert, Daniel uhttp://link.springer.com/10.1007/s00114-011-0851-700644nas a2200181 4500008004100000022001400041245006300055210006300118260002000181300001400201490000800215100003300223700001600256700002500272700001600297700001900313856013000332 2012 eng d a0036-807500aConvergent Evolution Between Insect and Mammalian Audition0 aConvergent Evolution Between Insect and Mammalian Audition cApr-15-20122141 a968 - 9710 v3381 aMontealegre-Zapata, Fernando1 aJonsson, T.1 aRobson-Brown, K., A.1 aPostles, M.1 aRobert, Daniel uhttp://www.sciencemag.org/cgi/doi/10.1126/science.1225271https://syndication.highwire.org/content/doi/10.1126/science.122527101817nas a2200265 4500008004100000022001400041245012000055210006900175260001600244300001600260490000800276520100400284653002501288653001701313653001601330653001901346653001801365100001401383700003301397700001901430700001801449700001601467700001201483856005601495 2012 eng d a0027-842400aWing stridulation in a Jurassic katydid (Insecta, Orthoptera) produced low-pitched musical calls to attract females0 aWing stridulation in a Jurassic katydid Insecta Orthoptera produ cJun-03-2012 a3868 - 38730 v1093 a

Behaviors are challenging to reconstruct for extinct species, particularly the nature and origins of acoustic communication. Here we unravel the song of Archaboilus musicus Gu, Engel and Ren sp. nov., a 165 million year old stridulating katydid. From the exceptionally preserved morphology of its stridulatory apparatus in the forewings and phylogenetic comparison with extant species, we reveal that A. musicus radiated pure-tone (musical) songs using a resonant mechanism tuned at a frequency of 6.4 kHz. Contrary to previous scenarios, musical songs were an early innovation, preceding the broad-bandwidth songs of extant katydids. Providing an accurate insight into paleoacoustic ecology, the low-frequency musical song of A. musicus was well-adapted to communication in the lightly cluttered environment of the mid-Jurassic forest produced by coniferous trees and giant ferns, suggesting that reptilian, amphibian, and mammalian insectivores could have also heard A. musicus' song.

10abiological asymmetry10abiomechanics10abushcricket10acall evolution10aTettigoniidae1 aGu, J.-J.1 aMontealegre-Zapata, Fernando1 aRobert, Daniel1 aEngel, M., S.1 aQiao, G.-X.1 aRen, D. uhttp://www.pnas.org/cgi/doi/10.1073/pnas.1118372109