@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 {57934, title = {Spatial Mixing between Calling Males of Two Closely Related, Sympatric Crickets Suggests Beneficial Heterospecific Interactions in a NonAdaptive Radiation}, year = {2019}, abstract = {

Sympatry among closely related species occurs in both adaptive and nonadaptive radiations. Among closely related, sympatric species of a nonadaptive radiation, the lack of ecological differentiation brings species into continual contact where individuals are exposed to the risk of reproductive interference. Selection thus should cause divergence in multiple components mediating the reproductive boundary. Besides differentiation of reproductive signals per se, spatial segregation is a commonly proposed mechanism that can mitigate reproductive interference. Studying a pair of broadly sympatric, closely related cricket species from a nonadaptive radiation in Hawaii, we 1) quantified acoustic divergence of male songs and 2) tested alternative hypotheses of spatial distribution of calling males of the 2 species. Acoustic analyses of the recorded songs showed that, while the 2 species differed substantially in pulse rate, no spectral or fine temporal segregation of the pulse structure was evident, indicating the potential for acoustic masking. Moreover, we found that calling males of the 2 species are highly mixed both vertically and horizontally and showed the same preference for calling sites. More surprisingly, calling males were found to form mixed-species calling clusters where heterospecific males are closer to each other than conspecific males. Such an individual spacing pattern suggests low heterospecific aggression and/or high conspecific competition. Because females prefer higher sound intensity, heterospecific males may benefit, rather than interfere, with each other in attracting females. These findings offer a potential mechanism enabling species coexistence in sympatry.

}, keywords = {neighbor spacing, nonadaptive radiation, reproductive barrier, signaling site choice, spatial segregation, sympatric species}, doi = {10.1093/jhered/esz062}, url = {https://academic.oup.com/jhered/advance-article/doi/10.1093/jhered/esz062/5648033}, author = {Xu, Mingzi and Shaw, Kerry L} } @article {57887, title = {Effects of mining truck traffic on cricket calling activity}, year = {2019}, abstract = {

Anthropogenic noise is a global pollutant and several studies have identified its impact on wildlife. This research shows how the noise produced by mining affects crickets\’ acoustic communication. Two passive acoustic monitoring devices (SMII) were installed in a forest fragment located at 500 m from the Brucutu Mine in Brazil. Another two SMII were installed distant 2500 from the mine. The equipment was configured to record from 17:00 to 05:00 h during seven days in April 2013. The authors analyzed the spectral characteristics of acoustic activity of three species of crickets (Anaxipha sp., Gryllus sp., and a Podoscirtinae species) before, during, and after the passing of mine trucks. For comparison the authors analyzed the acoustic characteristics for Anaxipha sp. and Gryllus sp. found in the distant site. Results showed a calling interruption for all the species during truck transit. Gryllus sp. emitted calls with higher maximum frequencies, average power, and larger bandwidth in the site close to the mine. Podoscirtinae species emitted calls with lower minimum frequencies, higher average power, and large bandwidth in the close site. The authors show that insect acoustic behavior varies between areas with different levels of noise. The disruption of this behavior may have negative consequences for their reproductive success.

}, doi = {10.1121/1.5119125}, url = {http://asa.scitation.org/doi/10.1121/1.5119125}, author = {Duarte, Marina H. L. and Caliari, Ernesto P. and Marina D. A. Scarpelli and Lobregat, Gabriel O. and Young, Robert J. and Sousa-lima, Renata S.} } @article {43232, title = {The Seasonal Succession of Orthopteran Stridulation near Raleigh, North Carolina}, journal = {Journal of the Elisha Mitchell Scientific Society}, volume = {67}, year = {1951}, month = {June 1951}, pages = {87-95}, chapter = {87}, author = {B. B. Fulton} } @article {16473, title = {Systematics and Acoustics of North American Anaxipha (Gryllidae: Trigonidiinae)}, journal = {Journal of Orthoptera Research}, volume = {23}, year = {2014}, month = {Jan-07-2014}, pages = {1 - 38}, issn = {1082-6467}, doi = {10.1665/034.023.010210.1665/034.023.0102.s13}, url = {http://www.bioone.org/doi/abs/10.1665/034.023.0102}, author = {Thomas J. Walker and Funk, David H.} } @article {16466, title = {Acoustic preference functions and song variability in the Hawaiian cricket Laupala cerasina}, journal = {Proceedings of the Royal Society B: Biological Sciences}, volume = {267}, year = {2000}, month = {Oct-03-2001}, pages = {577 - 584}, abstract = {

Female preference functions for di\¡erent sexual traits can di\¡er signi\¢cantly, from {\textquoteleft}unimodal\’ to {\textquoteleft}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.

}, keywords = {acoustic communication, crickets, mate recognition, preference, sexual selection, song}, issn = {0962-8452}, doi = {10.1098/rspb.2000.1040}, url = {http://rspb.royalsocietypublishing.org/cgi/doi/10.1098/rspb.2000.1040}, author = {Shaw, K. L. and Herlihy, D. P.} }