@article {50909, title = {Morphological determinants of carrier frequency signal in katydids (Orthoptera): a comparative analysis using biophysical evidence}, journal = {Journal of Evolutionary Biology}, year = {2017}, month = {Apr-09-2018}, abstract = {

Male katydids produce mating calls by stridulation using specialized structures on the forewings. The right wing (RW) bears a scraper connected to a drum-like cell known as the mirror and a left wing (LW) that overlaps the RW and bears a serrated vein on the ventral side, the stridulatory file. Sound is generated with the scraper sweeping across the file, producing vibrations that are amplified by the mirror. Using this sound generator, katydids exploit a range of song carrier frequencies (CF) unsurpassed by any other insect group, with species singing as low as 600 Hz and others as high as 150 kHz. Sound generator size has been shown to scale negatively with CF, but such observations derive from studies based on few species, without phylogenetic control, and/or using only the RW mirror length. We carried out a phylogenetic comparative analysis involving 94 species of katydids to study the relationship between LW and RW components of the sound generator and the CF of the male\&$\#$39;s mating call, while taking into account body size and phylogenetic relationships. The results showed that CF negatively scaled with all morphological measures, but was most strongly related to components of the sound generation system (file, LW and RW mirrors). Interestingly, the LW mirror (reduced and non-functional) predicted CF more accurately than the RW mirror, and body size is not a reliable CF predictor. Mathematical models were verified on known species for predicting CF in species for which sound is unknown (e.g. fossils or museum specimens).

}, doi = {10.1111/jeb.13179}, url = {http://doi.wiley.com/10.1111/jeb.13179}, author = {Fernando Montealegre-Zapata and Ogden, Jessica and Jonsson, Thorin and Soulsbury, Carl D.} } @article {47329, title = {Wing mechanics, vibrational and acoustic communication in a new bush-cricket species of the genus Copiphora (Orthoptera: Tettigoniidae) from Colombia}, journal = {Zoologischer Anzeiger - A Journal of Comparative Zoology}, volume = {263}, year = {2016}, month = {Jan-07-2016}, pages = {55 - 65}, abstract = {

Male bush-crickets produce acoustic signals by wing stridulation to call females. Several species also alternate vibratory signals with acoustic calls for intraspecific communication, a way to reduce risk of detection by eavesdropping predators. Both modes of communication have been documented mostly in neotropical species, for example in the genus Copiphora. In this article, we studied vibratory and acoustic signals and the biophysics of wing resonance in Copiphora vigorosa, a new species from the rainforest of Colombia. Different from other Copiphora species in which the acoustic signals have been properly documented as pure tones, C. vigorosa males produce a complex modulated broadband call peaking at ca. 30 kHz. Since males of this species do rarely sing, we also report that substratum vibrations have been adopted in this species as a persistent communication channel. Wing resonances and substratum vibrations were measured using a \μ-scanning Laser Doppler Vibrometry. We found that the stridulatory areas of both wings exhibit a relatively broad-frequency response and the combined vibration outputs fits with the calling song spectrum breadth. The broadband calling song spectrum results from several wing resonances activated simultaneously during stridulation. Under laboratory conditions the calling song duty cycle is very low and males spend more time tremulating than singing.

}, keywords = {bioacoustics, biotremology, bush-cricket, laser Doppler vibrometer, resonance, tremulation, ultrasound}, issn = {00445231}, doi = {10.1016/j.jcz.2016.04.008}, url = {http://linkinghub.elsevier.com/retrieve/pii/S0044523116300584}, author = {Sarria-S, Fabio A. and Buxton, Kallum and Jonsson, Thorin and Fernando Montealegre-Zapata} } @article {20919, title = {Functional morphology of tegmina-based stridulation in the relict species Cyphoderris monstrosa (Orthoptera: Ensifera: Prophalangopsidae)}, journal = {The Journal of Experimental Biology}, volume = {220}, year = {2017}, month = {Dec-28-20172143}, pages = {1112 - 1121}, abstract = {

Male grigs, bush crickets and crickets produce mating calls by tegminal stridulation: the scraping together of modified forewings functioning as sound generators. Bush crickets (Tettigoniidae) and crickets (Gryllinae) diverged some 240 million years ago, with each lineage developing unique characteristics in wing morphology and the associated mechanics of stridulation. The grigs (Prophalangopsidae), a relict lineage more closely related to bush crickets than to crickets, are believed to retain plesiomorphic features of wing morphology. The wing cells widely involved in sound production, such as the harp and mirror, are comparatively small, poorly delimited and/or partially filled with cross-veins. Such morphology is similarly observed in the earliest stridulating ensiferans, for which stridulatory mechanics remains poorly understood. The grigs, therefore, are of major importance to investigate the early evolutionary stages of tegminal stridulation, a critical innovation in the evolution of the Orthoptera. The aim of this study is to appreciate the degree of specialization on grig forewings, through identification of sound radiating areas and their properties. For well-grounded comparisons, homologies in wing venation (and associated areas) of grigs and bush crickets are re-evaluated. Then, using direct evidence, this study confirms the mirror cell, in association with two other areas (termed \‘neck\’ and \‘pre-mirror\’), as the acoustic resonator in the grig Cyphoderris monstrosa. Despite the use of largely symmetrical resonators, as found in field crickets, analogous features of stridulatory mechanics are observed between C. monstrosa and bush crickets. Both morphology and function in grigs represents transitional stages between unspecialized forewings and derived conditions observed in modern species.

}, issn = {0022-0949}, doi = {10.1242/jeb.153106}, url = {http://jeb.biologists.org/lookup/doi/10.1242/jeb.153106https://syndication.highwire.org/content/doi/10.1242/jeb.153106}, author = {B{\'e}thoux, Olivier and Sarria-S, Fabio A. and Jonsson, Thorin and Mason, Andrew C. and Fernando Montealegre-Zapata} } @article {11175, title = {Ultrasonic reverse stridulation in the spider-like katydid Arachnoscelis (Orthoptera: Listrosceledinae)}, journal = {Bioacoustics}, volume = {23}, year = {2014}, month = {Feb-01-2014}, pages = {67 - 77}, abstract = {

This paper illustrates the biomechanics of sound production in the neotropical predaceous katydid Arachnoscelis arachnoides (Insecta: Orthoptera: Tettigoniidae). Described and previously known from only one male specimen, this genus of predaceous katydids resembles spiders in their general body appearance. To call distant females, male katydids produce songs by stridulation where one forewing possessing a sclerotized file rubs against a row of teeth (scraper) on the other wing. In most katydid species, the songs are produced during the wing-closing phase of the stridulation. Morphological comparative studies of the stridulatory apparatus of the type specimen of Arachnoscelis arachnoides and males of other closely related species suggest that this insect sings with a frequency of ca. 80 kHz to attract conspecific females. We found an abundant population of A. arachnoides in Central Northeast of Colombia and undertook a complete analysis of the biomechanics of stridulation in this species. Using ultrasound-sensitive equipment and high-speed video, we determined that male A. arachnoides sing at ca. 74 kHz and use elastic energy and wing deformation to reach such ultrasonic frequencies. In contrast to most katydids, males of this species produce their calls during the opening phase of the wing; this form of stridulation is discussed.

}, keywords = {biomechanics, Colombia, elastic energy, stridulation, ultrasound}, issn = {0952-4622}, doi = {10.1080/09524622.2013.816639}, url = {http://www.tandfonline.com/doi/abs/10.1080/09524622.2013.816639}, author = {Benedict D. Chivers and Jonsson, Thorin and Cadena-Castaneda, Oscar J. and Fernando Montealegre-Zapata} }