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/plain01618nas a2200145 4500008004100000245005200041210005200093260001900145520117200164100002001336700002801356700002501384700001901409856004401428 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/pt-pt/node/5799101444nas 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.2013.085701255nas a2200145 4500008004100000245004800041210004800089260001600137300001400153490000800167520084400175100002001019700001601039856005401055 2018 eng d00aTree cricket baffles are manufactured tools0 aTree cricket baffles are manufactured tools cJan-09-2018 a691 - 6930 v1243 a

Tree crickets use sound to attract mates and make acoustic baffles to increase their sound production efficiency. It has been recently discovered that these insects use a flexible yet inherited behavioural programme to make acoustically optimal baffles. Whether these baffles qualify as tools, however, remains controversial. Here, baffle‐using and baffle‐making behaviours are analysed using the most current and authoritative definition of tool use. The current definition of tool use does not require the tool to be detached from the substrate and includes attached but manipulable external objects. Given this schema, tree cricket baffles, which are attached but manipulated prior to use, must be considered tools. The mode of manufacture for a baffle is “Subtract,” and the mode of use is “Drape”.

1 aMhatre, Natasha1 aBertram, S. uhttp://doi.wiley.com/10.1111/eth.2018.124.issue-9