@article {58027, title = {Diversity of acoustic tracheal system and its role for directional hearing in crickets}, year = {2013}, abstract = {

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.

}, keywords = {Acoustic tracheal system, cricket, directional hearing, Interaural intensity difference (IID), Pressure difference receiver, Sound localization}, doi = {10.1186/1742-9994-10-61}, url = {http://frontiersinzoology.biomedcentral.com/articles/10.1186/1742-9994-10-61}, author = {Schmidt, Arne KD and R{\"o}mer, Heiner} } @article {57620, title = {Mechanisms of frequency-specific responses of ω neuron 1 in crickets (Teleogryllus oceanicus): a polysynaptic pathway for song?}, year = {2001}, abstract = {

In crickets (Teleogryllus oceanicus), the auditory interneuron \ω neuron 1 (ON1) responds to sounds over a wide range of frequencies but is most sensitive to the frequency of conspecific songs (4.5 kHz). Response latency is longest for this same frequency. We investigate the mechanisms that might account for the longer latency of ON1 to cricket-like sounds. Intracellular recordings revealed no evidence for appropriately timed postsynaptic inhibition of ON1 that might increase its latency, nor was latency affected by picrotoxin. The onset of excitatory postsynaptic potentials (EPSPs) was delayed for 4.5 kHz stimuli compared with ultrasound stimuli, pointing to a presynaptic locus for the latency difference. When ON1 is stimulated with high frequencies, discrete, apparently unitary EPSPs can be recorded in its dendrite, and these are latency-locked to spikes recorded simultaneously in the auditory nerve. This suggests that input to ON1 from high-frequency-tuned auditory receptor neurons is monosynaptic. In agreement with this, brief ultrasound stimuli evoke a single, short-latency EPSP in ON1. In contrast, the EPSP evoked by a brief 4.5 kHz stimulus consists of an early component, similar in latency to that evoked by ultrasound and possibly evoked by ultrasound-tuned receptors, and a later, dominant component. We interpret the early peak as arising from a monosynaptic afferent pathway and the late peak from a polysynaptic afferent pathway. Multiple-peak EPSPs, with timing similar to those evoked by sound stimuli, were also evoked by electrical stimulation of the auditory nerve.

}, keywords = {audition, auditory interneuron, cricket, excitatory postsynaptic potential, Insect, monosynaptic pathway, omega neuron 1 (ON1), polysynaptic pathway, song, Teleogryllus oceanicus}, author = {Faulkes, Z and Gerald S. Pollack} } @article {57618, title = {Representation of behaviorally relevant sound frequencies by auditory receptors in the cricket teleogryllus oceanicus}, journal = {Journal of Experimental Biology 1998 Jan;201 (Pt 1):155-63.}, volume = {201}, year = {1998}, pages = {155-163}, chapter = {155}, abstract = {

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.

}, keywords = {acoustic communication, compound action potential, cricket, sensory coding, Teleogryllus oceanicus, ultrasound}, author = {Gerald S. Pollack and Zen Faulkes} } @article {57601, title = {Auditory Sensitivity of an Acoustic Parasitoid (Emblemasoma sp., Sarcophagidae, Diptera) and the Calling Behavior of Potential Hosts}, journal = {Brain, Behavior and Evolution}, volume = {72}, year = {2008}, month = {Jan-01-2008}, pages = {16 - 26}, abstract = {

Using field broadcasts of model male calling songs, we tested whether Tibicen pruinosa and T. chloromera (Homoptera: Cicadidae) are candidate hosts for acoustic parasitoid flies. The model calling song of T. pruinosa attracted 90\% of the flies (Sarcophagidae: Emblemasoma sp.; all larvapositing females) when broadcast simultaneously with the model T. chloromera song, a phonotactic bias reconfirmed in single song playbacks. In paired broadcasts of model T. pruinosa songs with different relative amplitudes (3 dB or 6 dB), significantly more flies were attracted to the more powerful song, a result consistent with the responses predicted by a model proposed by Forrest and Raspet [1994]. Using intracellular recordings and dye injections, we characterized the sensitivity of auditory units in sound-trapped flies. Intracellular recordings from six auditory units (5 interneurons, 1 afferent) revealed best sensitivity for frequencies near 3-4 kHz, matching the predominant spectral components of the calling songs of both species of cicada. Interestingly, although flies could be attracted to T. pruinosa broadcasts throughout the day, hourly censuses of singing males revealed that calling occurred exclusively at dusk. Furthermore, the duration of the dusk chorus in T. pruinosa was significantly shorter than the midday chorus of the less attractive song of T. chloromera. We propose that the tight temporal aggregation of the dusk chorus time could function to reduce risk from attracted parasitoids.

}, keywords = {Chorus, Cicada, cricket, Diel Behavior, Emblemasoma, frequency tuning, interneuron, Ormia, parasitoid, phonotaxis, Tibicen}, issn = {0006-8977}, doi = {10.1159/000139458}, url = {https://www.karger.com/Article/FullText/139458}, author = {Farris, H.E. and Oshinsky, M.L. and Forrest, T.G. and Ronald R. Hoy} } @article {57564, title = {Effect of the Temporal Pattern of Contralateral Inhibition on Sound Localization Cues}, year = {2005}, abstract = {

We studied the temporal coding properties of identified interneurons in the auditory system of crickets, using information theory as an analytical tool. The ascending neuron 1 (AN1), which is tuned to the dominant carrier frequency (CF) of cricket songs, selectively codes the limited range of amplitude modulation (AM) frequencies that occur in these signals. AN2, which is most sensitive to the ultrasonic frequencies that occur in echolocation calls of insectivorous bats, codes a broader range of AM frequencies, as occur in bat calls. A third neuron, omega neuron 1 (ON1), which is dually tuned to both ranges of carrier frequency, was shown previously to have CF-specific coding properties, allowing it to represent accurately the differing temporal structures of both cricket songs and bat calls. ON1 is a source of contralateral inhibition to AN1 and AN2, enhancing binaural contrast and facilitating sound localization. We used dichotic stimulation to examine the importance of the temporal structure of contralateral inhibition for enhancing binaural contrast. Contralateral inhibition degrades the coding of temporal pattern by AN1 and AN2, but only if the temporal pattern of inhibitory input matches that of excitation. Firing rate is also decreased most strongly by temporally matched contralateral inhibition. This is apparent for AN1 in its mean firing rate; for AN2, high-frequency firing is selectively suppressed. Our results show that the CF-specific coding properties of ON1 allow this single neuron to enhance effectively localization cues for both cricket-like and bat-like acoustic signals.

}, keywords = {auditory, communication, cricket, information theory, phonotaxis, temporal coding}, doi = {10.1523/JNEUROSCI.0646-05.2005}, url = {http://www.jneurosci.org/cgi/doi/10.1523/JNEUROSCI.0646-05.2005}, author = {Marsat, Gary and Gerald S. Pollack} } @article {57423, title = {High background noise shapes selective auditory filters in a tropical cricket}, year = {2011}, abstract = {

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.

}, keywords = {acoustic communication, competition, cricket, directional hearing, Matched filters}, doi = {10.1242/jeb.053819}, url = {http://jeb.biologists.org/cgi/doi/10.1242/jeb.053819https://syndication.highwire.org/content/doi/10.1242/jeb.053819}, author = {Arne K. D. Schmidt and Riede, K. and Heiner R{\"o}mer} } @article {50731, title = {Anurogryllus Saussure, 1877 (Orthoptera: Gryllidae: Gryllinae) from southern Brazil: new species and new records}, journal = {Zootaxa}, volume = {4290}, year = {2017}, month = {Oct-07-2017}, pages = {559}, abstract = {

The aim of this work was to extend the taxonomic knowledge of the species of Anurogryllus Saussure, 1877 that occurs in the southern municipalities of Rio Grande do Sul State, Brazil. We found three different species, Anurogryllus tapes sp. nov. collected in municipalities of Cangu\çu and Cap\ão do Le\ão, Anurogryllus patos sp. nov. from Cap\ão do Le\ão and Anurogryllus toledopizai (de Mello, 1988) recorded from Cangu\çu, Cap\ão do Le\ão e S\ão Louren\ço do Sul. Here we present the descriptions of morphology, male genitalia and calling songs.

}, keywords = {bioacoustics, calling song, cricket, Ensifera, Orthoptera, Pampa biome}, issn = {1175-5326}, doi = {10.11646/zootaxa.4290.310.11646/zootaxa.4290.3.9}, url = {https://biotaxa.org/Zootaxa/issue/view/zootaxa.4290.3https://biotaxa.org/Zootaxa/article/view/zootaxa.4290.3.9}, author = {Red{\"u}, Darlan Rutz and Zefa, Edison} } @article {47589, title = {Processing of vibratory and acoustic signals by ventral cord neurones in the cricket Gryllus campestris}, journal = {Journal of Insect Physiology}, volume = {30}, year = {1984}, month = {Jan-01-1984}, pages = {575 - 585}, abstract = {

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.

}, keywords = {central coprocessing, cricket, interneurone, sound, vibration}, issn = {00221910}, doi = {10.1016/0022-1910(84)90086-6}, url = {http://linkinghub.elsevier.com/retrieve/pii/0022191084900866}, author = {K{\"u}hne, Roland and Silver, Susan and Lewis, Brian} } @article {47331, title = {Contribution to the taxonomy of Gryllus Linnaeus, 1758 in South America: Part I: Redescription of Gryllus argentinus Saussure, 1874 (Orthoptera, Grylloidea, Gryllidae)}, journal = {Entomological Science}, volume = {14}, year = {2011}, month = {Jan-01-2011}, pages = {87 - 93}, abstract = {

The genus Gryllus includes 82 described species that occur in America from Canada to Argentina as well as in several areas of Africa, Europe and Asia. There are 12 species in South America, which were described in the nineteenth century based on a small number of samples and inconsistent characters such as body coloration and external morphology. The aim of this article is to redescribe Gryllus argentinus Saussure, 1874 collected in the urban areas of Pelotas, Cap\ão do Le\ão and Rio Grande, in the state of Rio Grande do Sul, southern Brazil, highlighting phallic sclerites, calling song and body morphometry. We designate the lectotype male, provide a combination of diagnostic characteristics and discuss the taxonomic situation of South American Gryllus species.

}, keywords = {bioacoustics, Brazil, cricket, genitalia, insects, pars stridens}, doi = {10.1111/ens.2011.14.issue-110.1111/j.1479-8298.2010.00412.x}, url = {http://doi.wiley.com/10.1111/ens.2011.14.issue-1}, author = {Luciano de P. Martins and Zefa, Edison} } @article {17274, title = {New species of Endecous (Grylloidea, Phalangopsidae, Luzarinae) from the Igua{\c c}u National Park (Brazil), including bioacoustics, cytogenetic and distribution data}, journal = {Zootaxa}, volume = {4237}, year = {2017}, month = {Jan-03-2017}, pages = {454}, abstract = {

In this study we describe two new species of cavicolous-straminicolous crickets for southern Brazil. Endecous chape n. sp. and E. naipi n. sp. are sympatric crickets that inhabit the Atlantic Semideciduous Forest of the Igua\çu National Park and adjacent areas. The descriptions were based on morphological characters, mainly from male genitalia and tegmina of adult males. Furthermore, we describe the chromosomes and the calling song of one of the new species, E. chape n. sp., presenting a discussion about the morphology of the phallic complex of Endecous and a distribution map for the species of the genus. The type-material is deposited in the Museu de Zoologia da Universidade de S\ão Paulo (MZSP), and in the Cole\ç\ão de Insetos do Departamento de Zoologia (Zoology Department Insect Collection), Universidade Estadual Paulista\—UNESP\—Botucatu campus.

}, keywords = {calling song, chromosomes, cricket, insects, Orthoptera, taxonomy}, issn = {1175-5326}, doi = {10.11646/zootaxa.4237.310.11646/zootaxa.4237.3.2}, url = {http://biotaxa.org/Zootaxa/issue/view/zootaxa.4237.3}, author = {Pedro G. B. Souza-Dias and Neucir Szinwelski and Marcos Fianco and Elliott Centeno de Oliveira and Francisco de A.G. de Mello and Zefa, Edison} }