01976nas a2200169 4500008004100000245013200041210006900173520137300242653002701615653001201642653002101654653002001675653001501695100002101710700002001731856005501751 2007 eng d00aListening for males and bats: spectral processing in the hearing organ of Neoconocephalus bivocatus (Orthoptera: Tettigoniidae)0 aListening for males and bats spectral processing in the hearing 3 a

Tettigoniids use hearing for mate finding and the avoidance of predators (mainly bats). Using intracellular recordings, we studied the response properties of auditory receptor cells of Neoconocephalus bivocatus to different sound frequencies, with a special focus on the frequency ranges representative of male calls and bat cries. We found several response properties that may represent adaptations for hearing in both contexts. Receptor cells with characteristic frequencies close to the dominant frequency of the communication signal were more broadly tuned, thus extending their range of high sensitivity. This increases the number of cells responding to the dominant frequency of the male call at low signal amplitudes, which should improve long distance call localization. Many cells tuned to audio frequencies had intermediate thresholds for ultrasound. As a consequence, a large number of receptors should be recruited at intermediate amplitudes of bat cries. This collective response of many receptors may function to emphasize predator information in the sensory system, and correlates with the amplitude range at which ultrasound elicits evasive behavior in tettigoniids. We compare our results with spectral processing in crickets, and discuss that both groups evolved different adaptations for the perceptual tasks of mate and predator detection.

10aacoustic communication10ahearing10aPredator evasion10aReceptor tuning10aultrasound1 aHöbel, Gerlinde1 aSchul, Johannes uhttp://link.springer.com/10.1007/s00359-007-0245-701824nas a2200205 4500008004100000245012200041210006900163300001200232490000800244520115400252653002701406653003001433653001201463653001901475653002701494653001501521100002401536700001701560856004101577 1998 eng d00aRepresentation of behaviorally relevant sound frequencies by auditory receptors in the cricket teleogryllus oceanicus0 aRepresentation of behaviorally relevant sound frequencies by aud a155-1630 v2013 a

Teleogryllus oceanicus is particularly sensitive to two ranges of sound frequency, one corresponding to intraspecific acoustical signals (4-5 kHz) and the other to the echolocation cries of bats (25-50 kHz). We recorded summed responses of the auditory nerve to stimuli in these two ranges. Nerve responses consist of trains of compound action potentials (CAPs), each produced by the summed activity of a number of receptor neurons. The amplitude of the CAP is up to four times larger for stimuli at 4.5 kHz than for stimuli at 30 kHz, suggesting either that the extracellular spikes produced by receptors that respond to 4.5 kHz are larger than those that respond to 30 kHz, or that receptors fire more synchronously in response to stimulation at 4.5 kHz, or that more receptors respond to stimulation at 4.5 kHz. Neither unit spike amplitude nor conduction velocity (which is expected to vary with spike amplitude) differs for the two frequencies, and the responses to 4.5 kHz are not produced by more tightly synchronized receptor populations, as judged by CAP breadth. We conclude that more receptors respond to 4. 5 kHz than to 30 kHz.

10aacoustic communication10acompound action potential10acricket10asensory coding10aTeleogryllus oceanicus10aultrasound1 aPollack, Gerald, S.1 aFaulkes, Zen uhttps://bio.acousti.ca/it/node/5761802304nas a2200181 4500008004100000245008200041210006900123520165300192653002701845653001601872653001201888653002401900653002001924100002501944700001401969700001901983856012002002 2011 eng d00aHigh background noise shapes selective auditory filters in a tropical cricket0 aHigh background noise shapes selective auditory filters in a tro3 a

Because of call frequency overlap and masking interference, the airborne sound channel represents a limited resource for communication in a species-rich cricket community like the tropical rainforest. Here we studied the frequency tuning of an auditory neuron mediating phonotaxis in the rainforest cricket Paroecanthus podagrosus, suffering from strong competition, in comparison with the same homologous neuron in two species of European field crickets, where such competition does not exist. As predicted, the rainforest species exhibited a more selective tuning compared with the European counterparts. The filter reduced background nocturnal noise levels by 26 dB, compared with only 16 and 10 dB in the two European species. We also quantified the performance of the sensory filter under the different filter regimes by examining the representation of the species-specific amplitude modulation of the male calling song, when embedded in background noise. Again, the filter of the rainforest cricket performed significantly better in terms of representing this important signal parameter. The neuronal representation of the calling song pattern within receivers was maintained for a wide range of signal-to-noise ratios because of the more sharply tuned sensory system and selective attention mechanisms. Finally, the rainforest cricket also showed an almost perfect match between the filter for sensitivity and the peripheral filter for directional hearing, in contrast to its European counterparts. We discuss the consequences of these adaptations for intraspecific acoustic communication and reproductive isolation between species.

10aacoustic communication10acompetition10acricket10adirectional hearing10aMatched filters1 aSchmidt, Arne, K. D.1 aRiede, K.1 aRömer, Heiner uhttp://jeb.biologists.org/cgi/doi/10.1242/jeb.053819https://syndication.highwire.org/content/doi/10.1242/jeb.05381902436nas a2200229 4500008004100000022001400041245008800055210006900143260001600212300001600228490000800244520157900252653002701831653001901858653002701877653002901904653002001933653002301953100002501976700001902001856018602020 2016 eng d a0022-094900aFunctional relevance of acoustic tracheal design in directional hearing in crickets0 aFunctional relevance of acoustic tracheal design in directional  cMar-10-2017 a3294 - 33000 v2193 a

Internally coupled ears (ICEs) allow small animals to reliably determine the direction of a sound source. ICEs are found in a variety of taxa, but crickets have evolved the most complex arrangement of coupled ears: an acoustic tracheal system composed of a large cross-body trachea that connects two entry points for sound in the thorax with the leg trachea of both ears. The key structure that allows for the tuned directionality of the ear is a tracheal inflation (acoustic vesicle) in the midline of the cross-body trachea holding a thin membrane (septum). Crickets are known to display a wide variety of acoustic tracheal morphologies, most importantly with respect to the presence of a single or double acoustic vesicle. However, the functional relevance of this variation is still not known. In this study, we investigated the peripheral directionality of three co-occurring, closely related cricket species of the subfamily Gryllinae. No support could be found for the hypothesis that a double vesicle should be regarded as an evolutionary innovation to (1) increase interaural directional cues, (2) increase the selectivity of the directional filter or (3) provide a better match between directional and sensitivity tuning. Nonetheless, by manipulating the double acoustic vesicle in the rainforest cricket Paroecanthus podagrosus, selectively eliminating the sound-transmitting pathways, we revealed that these pathways contribute almost equally to the total amount of interaural intensity differences, emphasizing their functional relevance in the system.

10aacoustic communication10ainsect hearing10aInternally coupled ear10alaser Doppler vibrometry10aMatched filters10aSound localization1 aSchmidt, Arne, K. D.1 aRömer, Heiner uhttp://jeb.biologists.org/lookup/doi/10.1242/jeb.145524https://syndication.highwire.org/content/doi/10.1242/jeb.145524https://syndication.highwire.org/content/doi/10.1242/jeb.14552402101nas a2200181 4500008004100000022001400041245016200055210006900217260001600286520134800302653002701650653002101677653002101698653001501719100002401734700002701758856013401785 2017 eng d a0024-406600aSubspecies-specific song preferences and diverged heterospecific discrimination in females of the bush-cricket Isophya kraussii (Orthoptera: Phaneropterinae)0 aSubspeciesspecific song preferences and diverged heterospecific  cSep-09-20173 a

Divergence of the acoustic signals used in mate calling may be an important driver of speciation. Male song may vary accordingly to, in mismatch with or independently of female preferences. Therefore, to estimate the importance of male signal variation between subspecies, female preferences against subspecies-specific signal variants must be tested. We examined the female response probability in the two subspecies of the bush-cricket Isophya kraussii for consubspecific and heterosubspecific male signals, and also for the song of a closely related species (I. camptoxypha), which is sympatric with one, but allopatric to the other subspecies. Performing no-choice playback experiments, we found that females of both subspecies responded to the male song of their own subspecies with significantly higher probability than to heterosubspecific and heterospecific songs. Response specificity for consubspecific vs. heterosubspecific signals was not significantly asymmetric comparing the two subspecies. A significant difference was found, however, in the discrimination of heterospecific calls: females showed stronger discrimination against the song of I. camptoxypha in the subspecies sympatric with that species. Our results are best explained by a tightly covarying, stepwise coevolution of male signals and female preferences.

10aacoustic communication10amate recognition10asignal evolution10aspeciation1 aOrci, Kirill, Márk1 aIorgu, Ionuț, Ștefan uhttp://academic.oup.com/biolinnean/article/doi/10.1093/biolinnean/blx094/4110201/Subspeciesspecific-song-preferences-and-diverged02689nas a2200193 4500008004100000022001300041245010200054210006900156260001600225520202600241653002702267653002502294653001302319653002102332653002502353100002802378700002302406856006602429 2017 eng d a0378595500aThe heterospecific calling song can improve conspecific signal detection in a bushcricket species0 aheterospecific calling song can improve conspecific signal detec cJan-09-20173 a

In forest clearings of the Malaysian rainforest, chirping and trilling Mecopoda species often live in sympatry. We investigated whether a phenomenon known as stochastic resonance (SR) improved the ability of individuals to detect a low-frequent signal component typical of chirps when members of the heterospecific trilling species were simultaneously active. This phenomenon may explain the fact that the chirping species upholds entrainment to the conspecific song in the presence of the trill. Therefore, we evaluated the response probability of an ascending auditory neuron (TN-1) in individuals of the chirping Mecopoda species to triple-pulsed 2, 8 and 20 kHz signals that were broadcast 1 dB below the hearing threshold while increasing the intensity of either white noise or a typical triller song.

Our results demonstrate the existence of SR over a rather broad range of signal-to-noise ratios (SNRs) of input signals when periodic 2 kHz and 20 kHz signals were presented at the same time as white noise. Using the chirp-specific 2 kHz signal as a stimulus, the maximum TN-1 response probability frequently exceeded the 50% threshold if the trill was broadcast simultaneously. Playback of an 8 kHz signal, a common frequency band component of the trill, yielded a similar result. Nevertheless, using the trill as a masker, the signal-related TN-1 spiking probability was rather variable. The variability on an individual level resulted from correlations between the phase relationship of the signal and syllables of the trill. For the first time, these results demonstrate the existence of SR in acoustically-communicating insects and suggest that the calling song of heterospecifics may facilitate the detection of a subthreshold signal component in certain situations. The results of the simulation of sound propagation in a computer model suggest a wide range of sender-receiver distances in which the triller can help to improve the detection of subthreshold signals in the chirping species.

10aacoustic communication10aauditory interneuron10aEnsifera10asignal detection10astochastic resonance1 aAbdelatti, Zainab, A.S.1 aHartbauer, Manfred uhttp://linkinghub.elsevier.com/retrieve/pii/S037859551730211302511nas a2200253 4500008004100000022001300041245012200054210006900176260001600245300001200261490000800273520169800281653002701979653001502006653002202021653002102043653002702064653002102091653001502112653001702127100002302144700002402167856006602191 2017 eng d a0003347200aDivergent mechanisms of acoustic mate recognition between closely related field cricket species ( Teleogryllus spp.)0 aDivergent mechanisms of acoustic mate recognition between closel cJan-08-2017 a17 - 250 v1303 a

Effective recognition of conspeci fi c mating signals reduces the risk of maladaptive hybridization. Dis- secting the signal recognition algorithms that underlie preferences is a useful approach for testing whether closely related taxa evaluate the same or different signal features to achieve mate recognition. Such data provide information about potential constraints and targets of selection during evolutionary divergence. Using a series of mate choice trials, we tested whether closely related, but genetically and phenotypically divergent, fi eld cricket species ( Teleogryllus oceanicus and Teleogryllus commodus ) use shared or distinct recognition algorithms when evaluating acoustic male calling songs. These species overlap in sympatry, show premating isolation based on female discrimination of male calling songs, yet are capable of producing hybrid offspring. Unexpectedly, female selectivity for features of male song differed between the two species. We found that the two species use a combination of shared and unique signal fi ltering mechanisms, and we characterized how information about male carrier frequency, pulse rate and temporal patterning is integrated to achieve song recognition in each species. These results illustrate how comparatively few, simple modi fi cations in key components of signal recognition algo- rithms can lead to striking interspeci fi c discrimination between closely related taxa, despite apparent signal complexity. The fi nding that some steps during signal recognition and fi ltering are shared between the species, while others differ, can help to identify behavioural traits targeted by selection during evolutionary divergence

10aacoustic communication10adivergence10afemale preference10amate recognition10areproductive isolation10asexual selection10aspeciation10aTeleogryllus1 aBailey, Nathan, W.1 aHennig, R. Matthias uhttp://linkinghub.elsevier.com/retrieve/pii/S000334721730182302002nas a2200229 4500008004100000022001400041245010300055210006900158260001600227300001400243490000800257520129000265653002701555653001301582653002101595653001501616653002101631653000901652100001701661700002001678856007401698 2000 eng d a0962-845200aAcoustic preference functions and song variability in the Hawaiian cricket Laupala cerasina0 aAcoustic preference functions and song variability in the Hawaii cOct-03-2001 a577 - 5840 v2673 a

Female preference functions for di¡erent sexual traits can di¡er signi¢cantly, from `unimodal’ to `open ended’. Through the study of acoustic communication in anurans, several studies have reported an association between static (stereotyped) traits versus dynamic (variable) traits and preference function shape (unimodal versus open ended, respectively). Observing a similar pattern in a phylogenetically independent group would suggest that deterministic forces have caused a relationship between signal variability and preference function shape in acoustic signalling systems. We examined this phenomenon in crickets, another animal characterized by intersexual acoustic communication. We measured the within- male variability for three acoustic features of the male calling song in Laupala cerasina and the corresponding shape of the female preference function for each of these features. We o¡er support for the generalization that open-ended preference functions correspond to relatively dynamic courtship traits and unimodal preference functions correspond to relatively static courtship traits. We discuss the evolutionary signi¢cance of these ¢ndings in the context of the natural history of the Laupala species radiation.

10aacoustic communication10acrickets10amate recognition10apreference10asexual selection10asong1 aShaw, K., L.1 aHerlihy, D., P. uhttp://rspb.royalsocietypublishing.org/cgi/doi/10.1098/rspb.2000.104002042nas a2200205 4500008004100000022001400041245007700055210006900132260001600201300001400217490000800231520141900239653002701658653002001685653001801705653001801723653001501741100002501756856005501781 2014 eng d a0340-759400aSelective phonotaxis of female crickets under natural outdoor conditions0 aSelective phonotaxis of female crickets under natural outdoor co cJan-03-2014 a239 - 2500 v2003 aAcoustic mate choice in insects has been extensively studied under laboratory conditions, using different behavioural paradigms. Ideally, however, mate choice designs should reflect natural conditions, including the physical properties of the transmission channel for the signal. Since little is known about the discrimination ability of females between male song variants under natural conditions, we performed phonotaxis experiments with female field crickets (Gryllus bimaculatus) outdoors, using two-choice decisions based on differences in carrier frequency, sound pressure level, and chirp rate. For all three song parameters, minimum differences necessary for a significant preference between two song models were considerably larger outdoors compared to laboratory conditions. A minimum amplitude difference of 5 dB was required for a significant choice in the field, compared to only 1–2 dB reported for lab-based experiments. Due to the tuned receiver system, differences in carrier frequency equal differences in perceived loudness, and the results on choice for differences in carrier frequency corroborate those in amplitude. Similarly, chirp rate differences of 50 chirps/min were required outdoors compared to only 20 chirps/min in the lab. For predictions about patterns of sexual selection, future studies need to consider the different outcomes of mate choice decisions in lab and field trials.10aacoustic communication10aDecision making10aFemale choice10aField cricket10aphonotaxis1 aHirtenlehner, Stefan uhttp://link.springer.com/10.1007/s00359-014-0881-7